Sowing seeds for a spring harvest in a heated greenhouse

[hedgehogneil]

Hello, I installed a new Rhino greenhouse this year and have just installed a heater. I think 7 degrees is the lowest temperature to maintain that avoids everything dying and doesn't run up too much of a bill. I have also a heated seed mat, albeit not used yet.

I want to grow some things in the greenhouse over winter and have sown some salad in troughs but I wanted to grow some black kale as well. If I sow seeds now using the mat to help get them started, is it a problem in terms of the timing given the date to sow on the packet is no later than July.

Seed sowing dates always confuse me as I don't know if it applies to a heated greenhouse where I have some sort of climate control and element protection.

Black kale is an example, but if there's anything else I decide to try and sow for a spring harvest, is it just a case of give it a go or should I strictly obey the packet?

Thanks and apologies if it's a stupid question, just wanted to try and reap some return on the not insignificant investment of the greenhouse!
Neil.

[Jungle Jane]

Shorter daylight hours can affect growth but I would try lots of seeds,not tender plants like tomatoes or peppers. Plant leaves might be smaller,let us know what happens it’ll be interesting to see. A heated greenhouse will be really handy in March for sowing tomatoes & peppers & leaving them out there day & night,I can’t do that,I bring mine in & out every day it’s so time consuming congratulations getting all sorted,it sounds like a lovely greenhouse.

[burnie]

I've got a rhino, sound piece of kit, good luck with your growing, I don't grow much over winter up here in NE Scotland, lack of light as has been mentioned being one of the main reasons, maybe think of adding grow lights as well as some heat?

[Can the Man]

Try carrots and beetroot they are fairly hardy and should grow. You could also try some potatoes to have for Christmas. I put in some pentland javelin and some roosters to try them.

[veggiechicken]

Seed sowing dates always confuse me as I don't know if it applies to a heated greenhouse where I have some sort of climate control and element protection.

Black kale is an example, but if there's anything else I decide to try and sow for a spring harvest, is it just a case of give it a go or should I strictly obey the packet?

My advice (which I follow) is ignore the seed packet advice, sow a few seeds when you can and if its a success do it again next year. If its not - lesson learnt.
Over winter the problem is light levels. Even winter hardy plants will slow down if there's not enough light. They go into limbo over winter and then go mad with the first hint of spring sunshine (as we all do).
You can grow many seeds all year round as micro greens and kale is ideal for cutting small. Don't expect the mega leaves that you might grow in the garden though.
Winter growing is about managing your expectations as well as your GH temperature.
I don't heat my GHs but still manage to grow veg over winter.

[hedgehogneil]

Hello, thanks for the replies. I shall begin by thinking I know more than the person who wrote the packet instructions and give lots of things a go! If there's anything to note next spring I will share for any interest.
Thank you,
Neil.

[bramble]

As everyone else points out.
It's not just about the heating
Shorter days, with dark mornings and evenings.
Very low light levels make it a challenge to keep growing in the winter.
It's not impossible, do give it a go,