Growing in greenhouse in winter

[Gattusso]

Hello this is my first full year of growing my own and was wondering does anybody know if the likes of cauliflower /cabbage/carrots can be grown in greenhouse over winter seems a shame to have it dormant. The greenhouse is unheated (can be heated if needed)

[Noosner]

Hmm... things like cauli, kale, cabbage and sprouts are fine with winter cold - in fact I think it improves some of them - so you might as well grow them outdoors.

With other veg such as carrots, I think it isn't just a question of heat, but of light. If you can afford to add hydroponic lighting as well as heating, I think you can probably do just about anything! But in the normal run of things I don't think there is enough light in winter to grow carrots.

I may be wrong, and someone may come along in a minute with a variety that grows in winter. You can certainly grow some varieties of lettuce in winter e.g. winter marvel, although they do grow quite slowly.

[veggiechicken]

Hello Gattusso and welcome to the Grapevine.
You can grow lots of things in the GH in the winter. Last year, I grew carrots in tubs, lettuces and mixed salad leaves and I have some cabbage growing in there all year round.
My advice, as always, is give it a go

[Bren In Pots]

I sow my winter lettuce in modules at the end of August then it gets planted in the border when the toms have finished.

[Gattusso]

Thanks all I'll certainly try different things through the winter. not going to invest in grow lights just yet too much of a novice.

[arpoet]

Putting lights and heat into the greenhouse ups the costs of growing. I prefer to use the space and shelter for giving next years spring and early summer crops and head start. Early tatties in tubs that can be moved out when conditions are right are one thing. So are starting off Broadies and peas and onion sets, etc.

[Two_Sheds]

anybody know if the likes of cauliflower /cabbage/carrots can be grown in greenhouse over winter

No.

These winter crops are fine to over-winter (outside or in a polytunnel), but almost nothing can be sown in autumn expecting a winter crop.

Light is what makes plants grow, and there just isn't enough of it in winter.

[Scarlet]

I grow Durham early cabbage in mine. Sow in modules now. Plant in the beds when the toms come out. You can use in early spring as greens or leave a while for them to head up. It works for me as they are finished in time for planting in the toms late May.

[teakdesk]

Quote Originally Posted by Gattusso...
anybody know if the likes of cauliflower /cabbage/carrots can be grown in greenhouse over winter

No.

These winter crops are fine to over-winter (outside or in a polytunnel), but almost nothing can be sown in autumn expecting a winter crop.

Light is what makes plants grow, and there just isn't enough of it in winter.

True, plants need light and a temperature of about 15degC to grow.

In late Autumn and late Winter there are often sunny days but not enough heat to initiate growth.

However, when the sun shines the temperature of my cold, unheated greenhouse can get to the magical 15degC so I have both light and heat together = growth.

So I can extend the growing season of cabbage, lettuce and even pots of potatoes by growing them in the greenhouse.

But as you say, I couldn't sow seed late in the year and expect a crop even if I heated my greenhouse, but by planning earlier I can help my crop using the cold greenhouse!

[Alison]

I use my tunnel to extend the growing season at both ends, things grow for longer into the autumn and start earlier in the spring that outside as although the light is very important, the protection helps too. I always put spring cabbage, calabrese and caulis in my tunnel in about October and they crop very early before the toms go in and before anything outside. Need next to no care or protection either which is a big bonus. Also plant up winter salads, spring onions, spinach and chard. All work really well.

[bario1]

Parsley sown in the next month or so also seems to do fine in a pot over winter.

[Thelma Sanders]

Joy Larkcom says that plants grow at 6C specially if also protected from the wind
Things do slow down completely in the coldest spells - but any sign of mild/bright weather and they are growing again........
I sow Seeds of Italy Misticanza (radicchio/lettuce mix) a few times over the winter period and it does grow - albeit slowly. Lettuce often germinates better at low temperatures than it does in Summer.

I also sow lambs lettuce, rocket, mizuna, tatsoi and endive Cornet De Bordeaux in Autumn for eating through winter, picking off leaves as and when.
Chard and perennial spinach also grow slowly through winter, from an Autumn sowing...obviously putting on a spurt in Spring.

In Joy's book GYO Vegetables she has some brilliant ideas for winter greenhouses and polytunnels - well worth borrowing from the library IMO

[Gattusso]

Thanks Thelma seems as though there is plenty for me to grow during winter spell I shall look out for Joys book may be worth purchasing rather than borrowing. I have a terrible habit of not returning books on time.

[teakdesk]

Joy Larkcom says that plants grow at 6C

Indeed, cool growing plants such as brassicas can grow even at 5 or 6 degC but the growth is very slight. 15 to 25 degC is the preferred temperature range for significant growth in these plants.

Plants that prefer warm conditions such as tomatoes hardly grow below 15degC and 25degC is the best temperature for significant growth.

[Noosner]

Joy Larkcom says that plants grow at 6C specially if also protected from the wind
Things do slow down completely in the coldest spells - but any sign of mild/bright weather and they are growing again........
I sow Seeds of Italy Misticanza (radicchio/lettuce mix) a few times over the winter period and it does grow - albeit slowly. Lettuce often germinates better at low temperatures than it does in Summer.

I also sow lambs lettuce, rocket, mizuna, tatsoi and endive Cornet De Bordeaux in Autumn for eating through winter, picking off leaves as and when.
Chard and perennial spinach also grow slowly through winter, from an Autumn sowing...obviously putting on a spurt in Spring.

In Joy's book GYO Vegetables she has some brilliant ideas for winter greenhouses and polytunnels - well worth borrowing from the library IMO

I totally recommend Joy's book too! It is my Bible (well, one of them)