Photo of The Irish Times article on how I grow my extra-early potatoes - by Fionnuala Fallon. 20.1.11
You can still sow peas for pea shoots - 'Meteor' or Oregon Sugar Pod are good varieties widely available. Soaking overnight and pre-sprouting somewhere warm first is helpful to prevent rotting or mouse attack! Some varieties of non-hearting leafy cabbage greens such as Unwins 'Greensleeves', that have been specially bred for winter sowing, could start to produce useful leaves in the tunnel early in the new year if sown now. 'Cavalo Nero' and 'Ragged Jack' or Russian Red kales can still be sown for baby leaves/micro salads, as can some of the hardier oriental greens like mizuna, mibuna, oriental mustards, cress and oriental salad mixes - depending on the weather these can grow on quite quickly now if it's mild. If the weather is very cold after they've germinated, they will still grow on slowly, with growth speeding up early in the new year when the light increases.
Seedling micro-green crops like mustard and cress grown on damp kitchen towel or in seed compost and sprouting seeds can also be a useful addition to winter salads - and this is easy to do in a warm kitchen. Make sure you rinse any jar-sprouted seeds well and regularly - preferably 2/3 times a day, with filtered water, to avoid bacteria, moulds or spoilage diseases building up. The warmer your kitchen - the more often you will need to rinse them - but the faster they will grow.
It's often worth sowing a fast-growing early carrot variety such as 'Early Nantes' or 'Amsterdam Forcing' in pots, deep containers, or even in long modules like loo roll middles, for planting out into the tunnel later - these will overwinter perfectly if covered with fleece and will crop in late winter/very early spring - thereby avoiding early carrot fly. With a little more warmth - say a kitchen windowsill, parsley can still be sown - the flat leaved variety 'Italian Giant' is much hardier and is by far the most productive and best-flavoured.
Sow some hardy annuals for bees & to attract beneficial insects
Calendula, borage and limnanthes (poached egg plant) will all flower extra early next year if sown now and these will attract beneficial insects like hover flies to help with pest control and also bees to help with pollination of crops like early broad beans.
Germination of all of the above will naturally be far quicker given average room temperature in your house and the faster they germinate the less likelihood there is of seed rotting. If you germinate things in the house - you must put them out into the tunnel/greenhouse into good light as soon as they have germinated, otherwise they get drawn and spindly from lack of light - and they'll be far more prone to diseases. Another reminder that if it's necessary to water any seedlings in modules - then water them from below by sitting in a tray of water briefly for a minute or so. Never saturate them - and ventilate well. This will hugely cut down the risk of 'damping off' disease. Using a good organic, peat-free seed compost - like the Klassman which I use - is worthwhile too, I find that seedlings are far healthier in that. I then cover any seeds that need it with vermiculite which also promotes good drainage as well as air-circulation around seedling's delicate stems. If frost is forecast you can use fleece for overnight protection - but uncover them in the mornings to let the air in and dry the fleece well before using again otherwise it will give no protection.
There's still just time to sow a green manure crop, as soil temperatures are still above 50degF/10degC after a relatively mild autumn. Mustard, red clover, phacelia and Hungarian grazing rye are good ones to sow in the tunnel or greenhouse or for outside. Claytonia also makes a good green manure which encourages worm activity and is also a useful, fast-growing edible salad in winter. These are all for digging in in early spring. They provide protection and cover for soils to prevent leaching of nutrients, provide carbon which is food for worms and soil dwelling bacteria - eventually becoming humus which encourages beneficial soil microbes and benefits plant health. Clover and phacelia also have very pretty nectar producing flowers which attract bees and other beneficial insects if you leave some at the end of a bed to flower in spring. Overwintered biennial herbs such a s parsley and coriander will flower early next year and do the same. Borage also makes a very good green manure. It makes a lot of green matter which encourages worms and also has a long tap root which draws up useful magnesium from low down in the soil profile. If you leave one or two plants to grow on it also adds a nice cucumber flavour to healthy spring smoothies and salads! Keep green manure seed beds damp until germination occurs and if we have a very cold winter, cover with fleece if hard frost is forecast while the seedlings are still small. Sow all seeds thinly to avoid overcrowding.
Garlic cloves can be sown/planted now - both outside and also in tunnels
For a really early crop of big bulbs next year - most varieties need cold weather for good root development. Choose firm, plump and healthy outside cloves from this year's crop, or buy certified virus-free ones from garden centres - not supermarket bought bulbs which will be unsuitable for this climate and may even bring in diseases like onion white rot - this can survive in the soil for about 20 years and be spread around the garden on your boots - infecting all members of the onion family including leeks! For the same reason I don't use onion sets in the vegetable garden. If I want some extra early onions - then I grow some sets in pots or containers. This way they're much earlier than any grown in the ground - and if you're unlucky enough to get any disease you can just throw the remains, along with the compost they were grown in, into the food/green waste recycling bin - rather than composting them and again spreading disease around the garden! I grow all my main crop onions from seed sown in early March - it's very easy and by doing this I avoid the possibility of onion white rot. Seed-sown onions also are far less likely to 'bolt' in difficult weather - a major problem this year - and they always keep far better. Mine always keep until well into spring - if they last that long!
To produce your earliest ever crop of potatoes in the New Year
If you haven't saved any early or second early tubers from your own spring crop, then keep an eye out for suitable varieties of potatoes such as 'Annabelle' in the veg departments of shops before Christmas. As long as the tubers you buy haven't been treated with anti-sprouting chemicals - these will be raring to go and will happily send out nice, fat, eager-to-grow shoots, if you take them out of the bag and bring them into the warm. These can then be used for planting 'extra early' potatoes in pots in mid-January, so that you can have your first new potatoes at Easter! (M&S usually have the best quality 'Annabelle' which readily grow when planted).
Some seed suppliers such as Tuckers may also have Lady Christl available before Christmas - although sadly they no longer do mail order. I have grown this variety for many years and it's the fastest 'bulking up' variety I've ever found for doing these 'extra-earlies', having usable sized tubers underneath them after only 8 weeks of growth - well before any other early variety. I start them all off in 2 litre pots which are easier to keep together in a group which can be easily covered with fleece if frost threatens.
Duke of York, Apache, Sharpe's Express and the purple-fleshed variety Violetta are also good for doing these as they are second-early varieties - but any potato variety will do - it still works. Although others may not be as early - especially maincrop varieties. But whichever variety you have - if they're grown in a polytunnel or greenhouse - they will still be miles earlier than any grown outside, so are well-worth growing!
Below there's a link to an article written by Irish Times journalist Fionnuala Fallon in 2011 on how I plant my 'extra early' potatoes, sadly without the photos, so I've taken a picture of the main picture in the paper, which you can see above.
(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.)