New 6' x 4' advice for the winter.

I'd like to grow some veg like radish, spring onions. Winter UK south can get to -5C. I will not be heating it. Advice welcome.

 

Hi,

Lots you can try according to site like these, though not sure about Spring Onions, will just depend on how warm or cold the winter is.

If you have the space, keep some house bricks or large containers of water in the greenhouse as these will act as overnight radiators.

How To Grow Winter Salads and Leaves in Greenhouses, Tunnels and under Cloches in The UK - Bite Sized Gardening

Winter Greenhouse: 11 Easy Vegetables to Grow in Yours

 

Essential to consider the available light, shortening days need maximum available so keep aspect clear and glass clean.
Ventilation necessary to avoid grey mould , so daily routine to give at least some fresh air in all but extreme frost periods. Restrict planting to prevent still- air traps. Possibly a fan on timer and even a gro-lamp.
Greenfly/aphids in early spring and late autumn can be problematic . Slugs and snails (and woodlice) at all times. Watch out for mice!
Consider micro-greens*, a useful dietary addition, simple to do and especially in new year when not much growth happens elsewhere. Perhaps start indoors on a windowsill and move out after 2 leaves show.
*brassicas, peas, sunflowers,spinach and lettuce- a good way to use up unsown seeds going out of date. I find radishes grow too slowly to be other than 'woody' after October.
You may find this of interest regarding survivable temperatures:
www.sustainablemarketfarming.com/2021/04/14/winter-kill-temperatures-of-cold-hardy-vegetables-2021/

 

You will struggle to grow anything without light, it is the short days more than the lack of heat that causes plants to shut down for the winter. There was a gardener on one of the Shetland Isles who grew salad crops in the winter using Actinic tube lights, nowadays you'd probably use some form of low wattage LED.

 

I only really grew stuff that basically overwintered in the greenhouse .
The idea being you plant or sow early autumn and then it overwinters and grows rapidly as spring comes along.
You used to be able to get a so called winter hardy version of White Lisbon spring onions and overwintering lettuce, I was never very adventurous but I think with all the foreign veg that are now available there must be lots of stuff to try, just not sure you will be cropping in January, but who knows.

 

Doubtless true but OP says South (England?) I,m right down on the Solent where winter often barely happens. Days are longer (than Angus) and some successes with Winter Density Lettuce, Aqua watercress, Ethiopean Kale, Chinese cabbage,Brown mustard, Mitzuna-green and red.Its definitely worth a go.

 

Here in Cornwall light is more important than heat so keep the glass clean. I grow lettuce, watercress, spring cabbage, spring onions and salad rocket. You need to start them off so they get to a reasonable size before the shortest days. Also regularly pick off mouldy leaves as the cold damp air encourages mould. The watercress was a free packet of seeds and did really well.
Another one is pea shoots - soak marrowfat peas you get for cooking and put quite thickly into seed trays of compost. Cut the shoots at 10cm 4 ins high and they will resprout several times.

 

Yes it makes a huge difference where you are growing, I bet you don't get Polar Bears walking all over your garden either............................