Topics for July: Holiday time and watering plants.....Rough guide to watering Tomatoes in containers & in the ground.....Side shoots on Tomatoes....Pollination of Tomatoes.....Other Tunnel Crops.....Free Watercress for Healthy Winter Salads......Thinking ahead to other late autumn and winter crops
Midsummer abundance, photo taken early morning. So full of crops that Gerry Kelly and I only had time to talk about just a few on radio in From Tunnel to Table
To say that polytunnel or greenhouse gardening can be challenging at times would be an understatement - especially with this year's long heatwave! But the rewards are many as you can see from the pictures both above and below. The picture above was taken at 6 am as currently for the rest of the day - the sun is so bright that it's impossible to take a photograph where you can see anything - there's so much glare! I don't know how the plants are able to cope with it - and some are really stressed. So is the gardener too! There is no doubt that it is climate-change which is causing the erratic extremes of weather that we have seen recently - but it's a fact - and we just have to learn to cope with it somehow! That's one of the reasons why growing so many different varieties of tomatoes for the Totally Terrific Tomato Festival is so valuable - because that way I can get a very good picture of how different tomato cultivars deal with the differing conditions here over the course of the summer. How they respond not just to heat - but also later in the early autumn to perhaps colder, more humid conditions. That's extremely important - as tomatoes are one of the most important food crops for gardeners and for commercial producers - not just here in Ireland but worldwide.
If I was putting up a polytunnel now I would definitely put in those side-opening vents which would make a huge difference right now to the soaring temperatures inside. It's been well over 100 deg F or 45 deg C most days for over a month or more and that's most unusual for Ireland. Years ago when we lived nearer to the coast a few miles away before we moved here - I had one of those small 'Garden Relax' plastic greenhouses, the forerunner of polytunnels, that were one of the first kinds available to amateur gardeners then. I also had a glasshouse - and with that it was much easier to prevent it from overheating in hot weather as I could use a paint called CoolGlass - which could be painted onto the outside of the roof very easilywith a household brush. It shaded the greenhouse when it was dry - and then became clear if there was a shower of rain. Sadly, there isn't anything like that yet for polytunnels! When we moved here, where it's high up and a lot more windy - I put up a new glasshouse, then another, and then another - before I finally gave in and had to be content with only polytunnels! The great thing aboujt polytunnels is that they can flex slightly in the wind - whereas a glasshouse just cracks - and once the wind gets in anywhere, and one or two panes blow out - then the whole house just shatters!
A Polytunnel is your own personal 'Mediterranean Fruit-fest' at this time of year!
Protection from the elements and warmth, even on cloudy days in summer, means that with the almost Mediterranean climate in a polytunnel at this time of year - you get so much more in return for the work you put in compared to growing fruit and vegetables outside. They're a great 'uplifter' on a grey gloomy day and also an incredibly cost-effective method of food production - no matter what size they are - if every inch inside is used as efficiently as it should be. They're also a way of keeping us gardeners sane when the weather's against us! Inside a polytunnel it can feel more like southern Europe - especially on a sunny day or even when it's so foul that you wouldn't even put a cat out - which can often happen in our Irish 'summers'! Mine certainly feels like that right now - a Mediterranean banquet! It's a real feast of colours, scents and tastes - of tomatoes, basil, cucumbers, sweet potatoes, courgettes, French beans, melons, peaches, raspberries, strawberries, figs, lemons, oranges, blackberries, cherries, cape gooseberries and grapevines literally dripping with fast-swelling, emerald bunches. The list goes on - with scarlet geraniums, nasturtiums, feverfew, orange marigolds and many valuable herbs like Perilla dotted about wherever they can be squeezed in, attracting insects like butterflies, hoverflies and with the constant hum of happy bees. I also grow some flowers in big pots which like hot dry conditions too - like some of the most richly scented but slightly more fussy roses that don't flower well outside here - like Emporeur du Maroc - which really hates our damp weather. It's scent hits me when I open the polytunnel in the early mornings at this time of year. It flowers in the polytunnel for months, repeat-flowering well, and it's wonderful for using in recipes especially for making Rose Petal Syrup. With the scent of the citrus blossom, lemon verbena and Jasmine filling the air too - it's really like being in another country altogether! Who needs Mediterranean holidays? I think the money's far better spent on a polytunnel where you can grow healthy food and enjoy relaxing in sunlight almost all year round! It's absolute heaven - and I can't bear to be away from mine for very long!
Things grow so incredibly fast in the almost tropical atmosphere that it can be all too easy to let yourself become a 'polytunnel slave' (a willing one in my case!) and rush round all the time watering, tending and harvesting. There just seems to be so much to do and so little time - even if you're up well before 6 am and working until it's dark! It's definitely necessary to relax in a deckchair in the sun occasionally though, admire it all and just enjoy the moment - something I try to do for least few minutes to do each day no matter how busy I am. I've never seen organic peaches or grapes for sale anywhere other than on very rare occasions in farmer's markets and even then they're imported from a long way away and a horrendous price - but they're easy to grow once you know how. At this time of year if you have a tunnel - you can bite into gloriously mouthwatering, properly ripe tomatoes warmed by the midsummer sun, with just a hint of a basil leaf. Or perhaps pick a few cherries and raspberries for a pre-breakfast snack, then sink your teeth into a lusciously yielding peach running with juice. I feel really sorry for all those poor souls who have to buy their fruit laced with chemicals, plastic wrapped, picked half ripe, bred to have skins tough enough to withstand the rigours of travelling hundreds of miles across Europe or further afield to reach the customer's plates days, or even weeks later!
I'm lucky enough to have two large polytunnels now to enjoy gardening in - I used to have four when I was producing organic crops commercially. Now it's a bit of a luxury to be able to grow whatever I want and to have fun experimenting with exciting new crops - rather then being tied to the same old purely commercial crops. But do you know something - they're still not big enough - I could fill at least four more polytunnels and still need more covered space! I would love to have a dedicated vine tunnel for instance. Just as the old walled gardens had their vine houses many decades ago - and a fig tunnel and a citrus tunnel and.................! The problem is - I could do with a few assistant gardeners as well!Ah well........a polytunnel is also definitely a place to dream in. And dreams are free!
They may not be the most beautiful structures in the world from the outside - but polytunnels are like people - it's what's on the inside that really counts! The more traditional greenhouses are very beautiful things I'll grant you - and who wouldn't want to own one? But they're also an expensive luxury item! Not only that - but as I've already said - being on a windy site here I lost three, before I gave up and decided that the only way I would ever be able to grow anything in the teeth of year-round south-westerly gales was in polytunnels! They may be slightly less attractive - but they're around half the price. Still not a cheap item - but I've proved over many years that any decent sized tunnel, if used properly all year round, will pay for itself in about 2-3 years. There's quite a lot you can do inside not only to improve their rather utilitarian looks, but also attract in all sorts of beneficial insects and bees, to keep pests away and pollinate your crops. If the many treats inside are eye-catching enough - one tends to overlook the less than beautiful surrounding structure.
What I call my 'Polytunnel Potager' can look really stunning inside all year round with the addition of many flowers and herbs growing alongside the vegetables! Not only that - it's a far more natural way to grow anything. Nature doesn't do acres of bare soil between neat rows of vegetables, as I said to Gerry Kelly recently on our 'From Tunnel to Table' radio programme. In a polytunnel - just as in Nature - diversity is strength! I've always studied and tried to reproduce the way that Nature grows things as closely as possible - giving each plant the conditions it needs to grow as well as it can and accompanying it with other plants that it might grow with naturally. The latest soil science is now proving that just as I had always believed - plants are far healthier when they're grown as communities with many different plant families all growing all mixed together, using the soil in different ways - instead of as long rows of isolated mono-crops with bare soil in between. The plants are healthier because growing them like this encourages different the bacteria and fungi in the soil which help all the plants to grow better and to produce the compounds they need to protect themselves from pests and diseases. As many of those same phytochemical compounds are the ones tht when we eat them also help to protect us from disease too - why would any sane person grow any other way? Surely it's only common sense? Why would anyone use chemicals that destroy all the vital soil life which Nature specifically co-evolved plants to work with - in a beautifully designed symbiotic relationship? It never made any sense to me - but perhaps in the short term it makes financial sense to those selling agricultural chemicals!
At this time of year, if the voluptuous abundance of your polytunnel doesn't make you feel smugly satisfied, or if seeing a friend's productive one doesn't make you long to own one yourself so that you too can grow all manner of good things - then you are a totally lost cause as far as any sort of fruit or vegetable gardening goes! There really is no hope for you!!If you don't have one, but are just thinking about it - then do go and have a look at one owned by a good gardener now, and just imagine how much money it could save you - because it really will! A polytunnel can fill your freezer and keep you in salads and a huge variety of other super-fresh, super-healthy vegetables, fruits and herbs all year round! Granted - polytunnels can be a huge amount of work - but they're really what you make of them - that's up to you. You could just grow perennial crops instead of changing them 3-4 times a year with the seasons as I mosltydo - although this way you do get less out of them.
The Totally Terrific Tomato Festival goes back to it's roots!
This year I'm once again growing a lot more different varieties of tomatoes for the Totally Terrific Tomato Festival - that this year is being held at our wonderful National Botanic Gardens Glasnevin in Dublin, for the very first time. I'm so excited about this as I first organised a tomato day there back in the early 1990's, on a much smaller scale, with Jeremy Cherfas - who was then director of the Heritage Seed Library of the then HDRA (now called Garden Organic) kindly donating some heritage seed and he came over from the UK to speak at it. That was my small seedling of an idea - which then became the Totally Terrific Tomato Festival which has grown stronger each year - now running for several years since I decided to resurrect it in 2012. I knew that people were becoming more interested in preserving so-call Heritage varieties - so I felt that the time was right. I also felt that making them aware of the importance of preserving genetic diversity was becoming increasingly important. This year it's being held on the 18th and 19th of August and will run for a fortnight after the initial weekend of talks and demonstrations.
For a 'tomatoholic' like me - it's the perfect excuse to go a bit over the top a bit on the tomato front! It's also a great way to trial new varieties and compare them with my tried and trusted 'old reliables'. When one's sowing tomatoes in March it's impossible to know what the summer will bring in terms of weather - some may hate cold nights - while others may be less fussy. In May again this year, temperatures were so hot that the developing plants were quite literally 'fried' at the top - looking as if someone had blasted them with a blow-torch! They were curling up their top leaves and looking 'fern like' - almost as if they had been sprayed with weedkiller. A lot of people have asked me about this leaf curling. It's the extremes of temperatures affecting the plants. Unfortunately in a polytunnel you have less control than in a greenhouse where you can apply shading paint to the glass. Even if you have one of those expensive, side opening tunnels, the sun can still scorch the tops of plants when it's at it's most intense. If any tomato variety can withstand those extremes and still produce a really good-tasting and worthwhile crop - then it's a pretty good one in my book! I'm growing most varieties both in the ground and in pots so that I can compare which do better in one or the other, or both. The ones in pots do need quite a lot of watering at this time of year or they can get stressed pretty quickly.
Holiday time and watering plants
Talking of watering crops - that reminds me! If you must go away on holiday - I've always found mid-October to be the very best time for a polytunnel owner. By then you've had the best of the summer and early autumn crops, and your tunnel should already be fully planted with crops to see you through the winter. These crops won't need too much tending or watering in October unless you're going away for weeks - as the weather's cooling down a bit. The tunnel needs much less fussing over at that time of year, and instead of the usual deflated feeling when you return from holidays - because of nothing to look forward to except long, cold, miserable grey days - it's nice to be able to look forward to continuous all-weather gardening, eating fresh salads and other delicious treats every day throughout the grey winter days! On the other hand - watering can be a huge problem if you go away in high summer. A few years ago I had a query from someone who'd spent a fortune on an automatic watering system for his polytunnel, got it all properly set up and went away with the family for a couple of weeks. He came back to find all the tomatoes blighted and everything dead poor man! I honestly think they're a complete waste of time and money for home gardeners, who want to grow a broad range of different crops in their tunnels, all with differing requirements. Even if you have the same one crop throughout your tunnel - there's still no guarantee it will work properly anyway. I have a friend who hates watering and spends ages fiddling about with hers! She could have watered her tunnel ten times over in the time she spends faffing around with all the bits and pieces!
I always think it's rather unfair of people to expect non-gardening neighbours, or even experienced gardening friends or family, to attempt to look after their polytunnel or greenhouse in the height of summer unless it's very small. Things can go badly wrong so very quickly. You've lost a whole summer's crops if they do - and perhaps good friends too! It's far too much of a responsibility. In the autumn most holidays are far cheaper anyway. If you can't afford one because you've just spent hundreds of euros or even a thousand on a new polytunnel - then instead of feeling deprived - just congratulate yourself instead for making a clever investment that will give you huge returns for many years to come! Most holidays cost far more than a small polytunnel - which unlike a holiday will bring you joy and good health every single day, all year round for many years - and also a comfortable place to sit in warm sunshine even on a frosty day in midwinter. (You won't believe this - but I promise you I have a friend who even has an old sofa in hers!)
I made a decision years ago to not fly anywhere any more - but only to go to places where I could go by car. It's far more carbon-friendly than flying to some noisy, garish and utterly pointless holiday resort! I love the quieter parts of the Mediterranean, where I pick up lots of ideas for food and planting - but even those are far less quiet nowadays. I have a confession to make here - my very rare holidays now are usually spent taking off in the car for just a couple of days and visiting gardens - or the best nurseries either here or in the UK - hunting for unusual fruits or 'jungle' plants - my secret addiction! I used to manage sometimes to combine this with work, in the form of my portrait sculpture - but sadly I can no longer do that now since smashing my right shoulder! Although my right arm's still ok for not too heavy gardening - I now no longer have the perfect control and reach necessary for very finely detailed portrait work. Luckily my gardening, especially in the polytunnels, more than satisfies my creative urges now.
At this time of year, I usually get up around 5.30 and do all the watering, feeding and side-shooting etc. of tomatoes before 9 am - as then it can become far too hot to hang around for long in the tunnels. Then mid-morning and mid-afternoon I damp down the tunnel paths with plenty of water so that it's evaporation helps to lower the temperature a little and keeps the air moving. I'm having to water the tomatoes and aubergines in containers twice a day at the moment. They're doing well though - and the aubergines in particular thoroughly enjoyed the recent very hot days of last week. 'Bonica F1' is the variety I always grow now, after trying many other varieties over the years. It's always the best performer whatever the weather does in our 'summers'. We often get low grey cloud for days on end here up on a hill not far from the coast. That is death to most aubergines - but no this one. As long as you're careful to gently pull fading petals away from the end of the developing flowers just as they start to fade to brown after the fruit has set - it always produces it's huge fruits. If you don't do this - they often start to rot. Do try it next year if you haven't tried aubergines before, or had no luck with them It's thoroughly reliable and came top in the RHS trials of aubergines a few years ago.
As tomato crops everywhere are starting to develop their fruits now- I'm getting a lot of questions about feeding and watering them.People always want to know how often you should water but there's no absolute formula.It's impossible to say - because you should only water when they need it - and every tomato plant and situation is different. It's something you just have to learn to 'play by ear'. Every garden situation is different depending on how you're growing things, whether they're in the ground or in containers of commercial potting compost or in the soil. It also depends where your greenhouse or tunnel is situated - whether it's in a very sunny spot or partly shaded and even how big it is, especially with a tunnel - as smaller tunnels can tend to have less air circulation. So these are just very general guidelines. Every year is different too -the weather obviously has a huge influence on how often things need watering - and as with most gardening - it's all about common sense and observation really - getting to know your plants, playing it by ear and noticing their needs daily in order to get the very best crops. Oddly enough - even different varieties vary in how you can get away with watering them. Sungold for instance, will split immediately if you water it just a bit too much when it has already 'set' it's skin and is ripening - but Rosada won't - unless you absolutely flood it! It's much more good-natured and far less temperamental. Individual varieties can all vary in their water requirements. Just like people - they're all different! You can't possibly make hard and fast rules - every tunnel, greenhouse or garden varies. Never just water a bit every day as a matter of course - that can lead to over-watering, and also cause roots to stay far too close to the surface, rather than going deeper to search for water and nutrients. Give plants a good soaking at night when watering in warm weather, so that it doesn't evaporate quickly as it would if watering during the day. And in the autumn do the reverse - if plants really need watering - then do it in the mornings - so that damp cold air isn't hanging around at night which can cause disease.
Rough guide to watering Tomatoes in containers.
I get a lot of questions about this. I grow some of my my tomatoes, peppers and aubergines in 10lt containers on grow bag trays. This is because I only ever use a quarter of the 'in the ground' ground space in my tunnel for the tomato family - which also naturally includes peppers and aubergines. In the tunnel - just as in the outside garden - I always operate a strict minimum four course rotation. Many people say there's no need to and don't bother for a few years, getting away with it for a while - but without doing that you can encounter soil problems like diseases and nematodes sooner or later. The containers I use are either recycled empty coleslaw buckets from the local deli, which I cut drainage holes in around the base - or sometimes 12 litre containers which I get from the local horticultural supply shop very cheaply compare to the DIY multiples! They are a similar size to the average large bucket. I start to feed with the brilliant Osmo organicTomato Food (which is high potash and encourages fruit production) as soon as the first truss has set. Why is Osmo so brilliant? Because you will never get magnesium or any other sort of deficiency when using this feed - and as it's also organic, it's safe to use and totally natural. When Dermot O'Neill came out to look at my tomatoes a few years ago for RTE's Mooney Show - he was amazed at how healthy my tomatoes in containers looked and how much fruit they were producing!
When plants are in containers - the roots are restricted and they can't forage far to find their own food, so they're obviously totally dependent on you. I start feeding when the first truss has set, I then use the tomato feed at every other watering - half strength (i.e. at one watering I feed at half strength, and at the other watering - I just use plain water.) I keep a water butt at tunnel temperature in the tunnel for watering the tomatoes - so that I don't use freezing cold water directly from the hose. Plants don't enjoy cold showers any more than people do! I don't water automatically - I play it by ear depending on how dry the growing medium is. I use a fifty/fifty peat-free and garden soil mix which I find best cushions the plants against heat or any variations in watering - I'm only human! Consistently just moist is they key - neither being permanently soaked and sitting in water - nor alternatively bone dry with the compost shrinking away from the side of the containers. I don't like to feed at full strength all the time as I feel the roots are more vulnerable but if I think something is looking just a little hungry - I will sometimes feed at full strength once or twice. The Osmo feeds are very gentle as they don't contain synthetic chemicals but just natural safe plant foods and won't burn plant roots - so you can feed at full strength if necessary, just as long as the compost is moist first.
It's fine to water into the top of the container top as long as youdon't do it right against the base of the stem. Thisavoids possibly causing rots where the base of the stem joins the roots especially in cold weather. This is always a vulnerable spot - particularly with aubergines and peppers. Always water around the edge of the container if possible - letting it drain through into whatever the plants are sitting in or on - they should usually soak this up over the next couple of hours if it's not too much. I sit my buckets on grow bag trays and if the plants haven't soaked up all the water after a few hours - I would tip it out. I never leave them sitting in water in the trays more than overnight - and only then if the plants have dried out a bit too much - but I try to prevent that. As I've already said - you sort of have to 'play it by ear' and get a 'feel' for it. I will often lift the edge of the container to feel it's weight before the plants get too big - over-watering is death to all plants in containers. If the top looks dry-ish but it still feels quite heavy, then it's probably ok for water but don't forget that the plants will make it feel heavier as they get bigger. If I'm not sure, I'll sometimes just scratch the surface of the compost to feel it. If the top is dry and the container feels a bit light then I know that water is needed immediately. Sometimes the compost will look a bit lighter in colour too - depending on the make. I never let plants get really parched to the point of almost wilting with the compost shrinking away from the sides of the container - this makes it far harder to re-wet any compost and can also make them drop their flowers or fruit. Drying out too much or erratic watering can stress the plants very badly and makes them far more vulnerable to physiological problems like 'blossom end rot' - which is caused by poor calcium transport in the plant tissues due to lack of consistent watering. Erratic watering also makes them much more attractive to pests like aphids and red spider. Stressed plants are always more vulnerable. Just like you and I - their immune systems are affected too, and they may not always be able to mobilise their defences as fast as they can when growing in ideal conditions in soil in the ground.
I know it does seems like a lot of trouble but when you get used to it, it becomes routine and is well worth it. You will have terrifically healthy crops of delicious tomatoes this way. Last year I grew about 70 plants in containers - mostly getting 8 fabulous trusses of fruit per plant. They certainly repaid all the TLC! All the expert books say you can only get 4 trusses from tomatoes when growing in containers. I do love to prove all those so-called 'experts' wrong! Successful organic growing is all about understanding your plants' needs, anticipating and preventing any possible problems. Proper old fashioned good gardening in other words! There's no substitute for knowing your plants!
Last year's Tomato Report 2016 gives information on the soil/organic potting compost mix I use in my containers. Many Garden Centres now stock all the Osmo organic feeds etc. and Klasmann Deilmann organic seed and potting composts - they're also available from Whites Agri, Lusk. Co. Dublin and Fruithill Farm in Cork. I wouldn't use anything else now - even for ornamental plants - all plants love it and grow very healthily. It's worth every cent of the extra expense! It's also well-worth knowing that I'm not destroying all the wonderful biodiversity in bogs in order to grow my plants - which is what peat users are doing!
Tomato plants growing in the ground
These are much easier to deal with as because the roots aren't restricted - so they're naturally far less vulnerable to fluctuations in watering. The same rules still apply of not watering directly against the base, not using freezing water from the hose and not letting them dry out completely. In the ground plants only need feeding about twice a week with the high potash Osmo Tomato Food - but again it depends on your soil and how fertile it was at planting. If I think plants are running out of steam and the leaves are maybe starting looking a bit 'yellowy' then I would give them a boost with the Osmo Universal feed which stimulates growth - but if they're growing in the ground and it's reasonably fertile - this shouldn't be needed. The last thing you want is too much lush leafy growth, which can cause disease if too crowded. If you only have a small number of plants to feed though - it's possible to make a fairly balanced feed from comfrey, nettles and borage stuffed into a water barrel. It stinks to high heaven - but is very effective! It's impossible to make enough to feed a lot of plants regularly though.
Side shoots on Tomatoes
Last month when talking about side shoots - I forgot to say that all tomato plants constantly keep trying to outwit you - as they are really genetically programmed to be bushes in actual fact - so they go on trying to be those by producing more side shoots all the time even where you've already taken some out. This is how they perpetuate themselves in the wild - by 'flopping' shoots over and 'walking' along to a new spot. You just have to be strict with them - otherwise they can very soon become a tangled, disease ridden, unproductive mess!
You mustkeephaving a good look at least every couple of days and nip out any more which may develop. I look over the plants every day, as I can guarantee I'll miss the odd shoot because I grow so many plants. Don't just do it once a fortnight, as I saw one gardening 'expert' journalist recommending recently in a local newspaper - they could be 60cm or 2 feet long by then at this time of year! The journalist in question, who shall remain nameless, is obviously not an experienced tomato grower! As you can see from the pictured examples here - which I left deliberately, to photograph -in just a week they can be very long, wasting the plant's valuable fruiting energy and seriously reducing air circulationif you leave them there! On the continental beefsteaks in particular, especially 'Pantano Romanesco' and occasionally even on cherry types, they may also make new 'side shoots' - like the ones pictured here, on the end or even the middle of flower/fruit trusses, so check there too and nip out immediately if necessary, otherwise they can attract moisture and set up ideal conditions for disease.
1. Side shoot developing on end of flower truss.
2. One week later - flower truss with new shoot on end getting much larger.
3. Same flower truss, after remedial action with secateurs!
Air circulation is absolutely vital to tomatoes, particularly all the continental beefsteaks, which can rapidly go down with botrytis (grey mould) and also blight at this time of year in very humid, damp conditions. Ventilating as much as possible, even on dull or rainy days, is most important. Leaving doors shut can even hinder pollination of flowers, as too high a temperature can actually damage the plants and the bees can't get in either! My tunnel doors are always open every day - unless there's a howling gale blowing from the wrong direction. And if the temperature on a very hot day still gets too high - then 'damping down' the paths, not the plants, will help to reduce the temperature by water evaporating - keeping the atmosphere 'bouyant' and the air moving.
Unlike conventional chemical growers, organic gardeners don't use systemic chemical fungicides, only occasionally surface, copper-based ones (I don't). I am amazed that anyone would still recommend spraying tomato plants with water - apparently in order to help pollination! That's rubbish! I'e also seen people recommending that you spray with garlic if you see aphids! It's totally unnecessary and as I mentioned again later - wetting tomato foliage in particular encourages disease. Aphids are again a sign of stressed plants probably grown with too much manure or other chemical fertiliser. Now I know some of the old 'conventional' text books used to recommend spraying with water many years ago - but they also used to recommend all sorts of nasty fungicides too! Things have moved on a bit since then, and cultivating plants organically means first and foremost giving plants the optimum conditions they need to promote healthy growth - that can mean taking a little bit more trouble occasionally but it really works. The old-fashioned 'fire brigade' mentality - of reaching for the sprayer for a quick fix whenever something goes wrong - instead of preventing it in the first place - doesn't have any place in an organic garden. I know it's a bit challenging trying to give everything the best conditions you can when you're growing so many different crops in one tunnel - but it is achievable with a little thought and care
Pollination of Tomatoes
Don't mist over tomato plants as I've already said! Tomatoes don't like the humid conditions that cucumbers do. Misting them frequently with water produces just the sort of damp conditions which are ideal for encouraging blight. Blight and other fungal spores ideally need a fine film of moisture on the leaves in order to germinate and multiply rapidly! All that is really required for good pollination is the right temperature, with even moisture at the roots, and encouraging pollinating insects into the tunnel to do their job, by growing flowers to attract them. Many of the more enlightened big commercial growers now use bees and even flies to pollinate crops in their vast greenhouses - something that crop research stations have always done. As I'm constantly saying -just grow lots of single, nectar producing flowers among your crops, both inside and outside, and you won't have any pollination problems.
Other Tunnel Crops
Cucumbers and melons are also growing really well in large containers now. Again, fruiting much earlier than those in the ground - by a couple of weeks. I'm experimenting a lot more again this year with containers, I have far more growing experience now than I had 37 years ago when my whole vegetable garden was grown in containers for two years, while renting a house en route to where we live now! That year I grew 45 lb of Runner beans on wigwams in recycled Marks and Spencer carrier bags (they were the strongest!). The other cucumbers are doing nicely in the ground, they're at the side of the tunnel where they don't get draughts and it's a bit more humid - they and melons are just about the only plants that really love sauna-like conditions! But even though they like warmth - they must be kept evenly moist at the roots - if they dry out at all at the roots and the air is humid they'll get powdery mildew very quickly - particularly as the air gets colder at night in autumn.
Aubergine 'Bonica' pictured here is growing in the same 10 litre buckets in a well-drained peat-free compost/soil mix and have just set their first fruits. I'm always careful to watch the flowers after they are just set - and when they start to fade I gently pull the browning flower downwards away from the calyx as that's where rots can set in- which is one of the main problem with aubergines in our climate. The other problem is stem rot where the stem joins the roots at the top of the compost. I avoid this by planting them slightly mounded up in the buckets and never watering against the stem but always around the outside of the bucket.
The yellow courgette Atena which I always grow as part of the cucurbitaceae rotation in the tunnel is already producing well. They will go on until early November with luck, the last few weeks under fleece. French bean 'Cobra' is as delicious and reliable as ever, and also Calabrese 'Green Magic'. It's really important to keep on top of picking all of these, and also watering regularly. If the plants dry out for too long in hot weather or if the pods, fruit or shoots get too big, that sends a hormone message back to the plant to say 'job done - we're on course to produce seed' and the plants will stop producing any more.
If you're growing early sweetcorn in the tunnel, when the plants start producing pollen give them a bit of a shake every day - wait until about midday if possible when the atmosphere has dried out a bit - so that the pollen dusts around nicely - it's often too humid first thing in the morning just after the doors are opened. Even if you've only got one plant in your greenhouse as one questioner at one of my recent talks said she had - it will still pollinate better if you do this. I always shake the outside plants too if there's no breeze to do the job - but that's rarely the case here on my very windy hill!
My tunnel sweetcorn 'Lark F1' is planted between pumpkins as usual - Queensland Blue, Jumbo Pink Banana, Golden and Blue Hubbards, Hokkaido etc. They are some of the best dense, deep orange fleshed ones for really long term storage and I won't ever risk the entire crop outside again in case we get yet another poor summer. They are too valuable for the winter larder. I will at least be assured of some then whatever the weather. I am being really strict with them though - and keeping them under severe 'house arrest' - pinching out all the shoots at four leaves or they would take over the entire tunnel. I've planted more outside too. The sweet corn is sown 2 or 3 to a pot and not thinned, then planted out 60cm/2ft intervals in a row. That way they pollinate each other well even though they're in a row rather than a block and produce at least 2 delicious cobs per plant.
If you're growing sweet potatoes, they don't want too rich a soil starting off otherwise they just produce masses of foliage - not tubers. They need similar soil to carrots, deep and well drained. They just get a light dusting of seaweed meal when planting and mulching with moisture retaining grass clippings to prevent weed growth. After that they only need watering occasionally to prevent them drying out. Like Oca and Yacon they don't start to produce their tubers until August - so from then on they get fed weekly with a high potash tomato feed - I use the Osmo food for them too. If you want to try growing them it's still worthwhile planting them now - and if they're a bit hungry in their pots by now just give them a liquid feed just to encourage them, then plant as above. Once you have good varieties you can keep tubers from your own crop each year and propagate slips from them.
The early peach on the north-east side at the end of the tunnel is covered with a fleece curtain, fixed with clothes pegs, once the fruit starts to change colour - as the rapidly ripening fruit screams 'eat me' at every blackbird within ten miles! There's always one or two in there doing a 'recce' - but no matter how gorgeous they look, they never touch them until they are just ripe - just when I say to myself "I'll pick them tomorrow" - I can almost guarantee they'll have a go at them. They seem to have a radar for ripening fruit! It doesn't seem to matter what netting I put up at the doors either - they always manage to ruin a few if I don't do this, but hiding them hiding them generally does the trick! The peach on the other side of the door doesn't ripen until early September. I bought both trees from Lidl - one just marked 'peach' and the other 'nectarine' from Lidl seven years ago. Magically one turned out to be a yellow-fleshed early peach and the other a late white-fleshed one - serendipity at work! Couldn't have planned it better! They're due for their summer pruning now. Leaving one or two good shoots to develop at the base of each branch to bear fruit next year, one shoot at the top to draw up the sap to the ripening fruit, and pruning other shoots two leaves beyond any ripening peaches. All other new shoots will be removed completely to let in air and light.
It's really important to prune tunnel-grown peaches properly, otherwise they quickly become an unproductive mess, taking over the entire tunnel, as they can make five or six feet of growth in a year. That happened to me many years ago when I didn't know how to prune them properly and the tree almost went through the roof! Practical experience is always the best teacher - you never forget your mistakes! The most important thing to remember is that they always fruit on the new green shoots made the previous year. Mine are trained as sort of half fan/half bushes or 'fushes' at the north end of the tunnel either side of the door, with roughly 9ft or 2 & 3/4m of width each, a space which is often wasted or full of rubbish in many tunnels. There, they are in full sun, but don't cast any shade on anything else, don't get peach leaf curl as they are protected from rain, and produce over 100 peaches every year! With my mini-gardens of flowers and perennial herbs like thyme and oregano at their feet they look good all year round and not an inch of space is wasted.
Some of the figs are ripening their early crop now - the necks of the fruit have weakened and fruits have started to 'flop', now drooping downwards, they will need another few days yet. Brogiotto Nero is the earliest - but Rouge de Bordeaux won't be far behind and then all the others will follow. I wait until I can see the first fruits starting to crack at the 'navel' end - that means they're really ripe. There is nothing more disappointing or wasteful than picking an unripe fig - they are so precious. It's what the Italians call the 'Breba' (overwintered) crop that's ripening now, and this autumn's main crop is just developing as smaller figlets on this year's new green shoots. Figs are very reliable in large containers - withstanding even really low temperatures in winter for short periods. I've got over a dozen varieties now with a range of ripening times. With even non-organic figs around one euro each in shops - they're well worth growing, very nutritious and dead easy. They are much more productive in a tunnel - really appreciating the extra warmth and shelter. Many varieties will crop twice a year.
While I'm on the subject of fruit - don't be tempted as I very stupidly was a couple of years ago by those lovely juicy-looking grapes trained as bushes in containers, which some of the garden retailers have at this time of year - the dead give away if you look at the label is that they usually have Italian wine names on them! They are grown in massive nurseries somewhere like Sardinia or southern Italy, and are totally unsuitable varieties for growing in Irish gardens - or even Irish greenhouses - we just don't get enough light and sun. If you only want vine leaves for 'Dolmades' that's fine - but they won't ripen their wood enough to produce decent grapes in our climate! I've also seen 'Muscat of Alexandria' for sale everywhere recently - that will do well in a warm greenhouse here - but not outside. Even in a greenhouse or tunnel it won't ripen until mid-late October or even November and is completely useless outside - but the labels don't mention that - if the importers even actually know! Mine is in a large tub, which I think hurries it up a bit - and it is utterly delicious, with a juicy muscat taste - in late OCTOBER! You could possibly ripen it in a warm porch too. Keep grapes under control (see June). I'm feeding all my grapes and figs in containers with every other watering now as the bunches of grapes are developing very fast. Never let them dry out completely, or the grapes shrivel and stop developing. The vines in the ground are all fed with tomato food once a week.
Free Watercress for Healthy Winter Salads
It's worth taking some new cuttings of watercress now, to produce nice plants for September planting to give good winter crops. It's by nature a creeping plant, and as soon as it's shoots are 4-5 in/10cm long - it starts to produce lots of roots at every leaf node in order to root itself into the soil. This is a great thing for grateful gardeners who may be short of salads - because as soon as you cut off those rooted side shoots and replant them they take off like rockets - and you will have a metre square bed of watercress in no time at all! It's a terrific plant for the damp, shadier parts of the garden or tunnel polytunnel which many other plants don't like. If you can buy a nice bunch, or a very fresh bag of watercress, choose the healthiest looking shoots, take off the lower leaves which may rot quickly in the water and infect the stems, put them in a jar of water for a few days and they will quickly start to produce roots. You can then pot these up in organic potting compost and away you go! When they're big enough - plant them out in really fertile, moist soil.
Contrary to popular opinion - watercress doesn't need running water - and indeed is not safe growing in damp mud or running water in a stream, as it may act as host to the tiny snail which can pass on liver fluke - not something you want! Keep the plants well watered after planting though, or they will become tough and too peppery, particularly at this time of year. Also pinch off any flower buds you see developing, or they will flower and set seed, which stops them producing the lovely lush growth you want. Watercress is a brassica, so needs to occupy that spot in your rotation, but is otherwise mostly trouble-free and hugely productive all winter. I keep watercress growing indefinitely by propagating plants like this. I always keep a pot of newly rooted shoots in a shady spot in the tunnel or outside in summer and then I propagate more for the winter from those. Mine just goes on from year to year. Even more plants for free - nothing better!!
Think ahead to late autumn and winter crops
Sorry to spoil the summer party but if you don't think about autumn and winter crops now - you won't have very much! Many of these are better sown outside in modules now and brought under cover later on, as it's far too hot in tunnels at the moment. See my 'What to Sow Now in July' list.
It's also time to order saffron bulbs now as they will need planting by the end of August. If you like living dangerously - you could wait until the beginning of August - when they're often discounted hugely so that seed/bulb companies can get rid of them. That's how I got mine originally. They're quite hardy and will grow outside, but they like to be baked in summer. Not only that - in my experience, we never get dry enough autumns to collect the saffron's valuables styles as it's always far too wet here! So I grow mine in the tunnel now - you can even grow them in well drained containers. Good drainage and a summer baking is all that they need. If you live in the drier climate of Essex you may be able to grow it outside. Saffron Walden was named after saffron - it grew well there in the Middle Ages. It's worth taking a bit of trouble with it as it's so expensive to buy. The ultimate in cheffy 'one-upmanship' is a risotto made from your very own home grown saffron!!
Don't forget that forcing chicory needs to be sown in the next week or so - or it won't be big enough to force for chicons in the winter. I also grow the very reliable 'Sugar Loaf' chicory, which folds up it's huge outer leaves all by itself and makes lovely crunchy, light green 'cos-like' hearts after Christmas - not too bitter, delicious and very welcome healthy winter salad. It grows exceptionally well in the tunnel too - and the hens love the outer crunchy green leaves in late winter when there's not much in the way of greens about for them.
Swiss chard also benefits from being sown before the end of July for winter cropping in the tunnel, it's well worth sowing into modules outside soon to plant in the tunnels later - where it's incredibly productive until the following late spring.
It's also a good time to sow another crop of carrots now as they should miss late carrot fly. An early, fast-growing variety such as Nantes is good they'll produce good sized sweet roots in the autumn
(P.S.I really enjoy sharing my original ideas and 40 years experience of growing and cooking my own organic food with you. It's most satisfying and naturally also very complimentary if others find "inspiration" in my work......But if you do happen to copy any of my material, or repeat it in any way online - I would appreciate it very much if you would please mention that it originally came from me, as it's the result of many years of hard work and often hard won-experience. Thank you.)