Aphids

How do you stop aphids in winter?
They are one of the main reasons I don’t grow in the polytunnels or bring things into the house. 
But this year I’m trying to start a few things early. My Cosmos that I’ve sown at completely the wrong time of year is actually doing very well. It’s about to flower. But I’ve just evicted it from the tunnel as it’s covered in aphids. Can’t see the little green sh**s on any of the seedlings, at the moment.
I use ladybirds to control them if I have a problem in summer but they won’t survive in winter and they should be hibernating anyway. 
So how do I control them in winter on young delicate plants?

I rarely get them...cosmos wont last through the winter so i would bin. They are easy to start in Spring.

Keep it well ventilated, fast sappy growth encourages aphids - so you want your plants to grow slow. Jeeping the doors open keeps the temps down. I used those fly papers

I have had huge issues with fungus gnats - so ensure you water from the bottoms to encourage a dry top on your compost.

Keep any compost bags as dry as you can - I'm sure lots of my fungus gnat issues came in with soaking wet compost from the shop.

I just squish them. If there's too many to squish by hand I would use a soapy spray. When the weather gets cold they don't reproduce very much so if you can get them now you'll reduce numbers in spring. Remove older, lower leaves and check the growing tips since that's where they like to hang out. I've got lots of brassica whitefly in the greenhouse at the moment, in colder weather they get dozy and don't fly away as quickly. The yellow sticky traps work well for whitefly but have also inadvertently killed hoverflies, parasitic wasps and spiders so I don't like using them anymore.

I stopped growing brassicas because of the white fly. Never had them in the greenhouse since.

I stopped growing brassicas because of the white fly. Never had them in the greenhouse since.

My outside kale is covered in the things notwithstanding they're covered in mesh.  I work on the principle that if any get into the pot it's extra protein for P. Hopefully a frost will kill them off.

I stopped growing brassicas because of the white fly. Never had them in the greenhouse since.

They're only really a problem on brassicas you eat the leaves of i.e. kale, which they seem to adore (and kalettes which are a kale x sprout cross). Which is one of the reasons why I've stopped growing full size kale and just harvest them as baby leaves for salads (also I don't really like big kale leaves, too tough and chewy). We harvest the asian greens they're on in the greenhouse regularly so they don't get time to build up numbers and cover the underside of whole leaves with their nymphs. Otherwise they're just a bit of a nuisance when they fly in your face. I find the mealy cabbage aphid much worse because they can badly stunt the growth of plants they feed on and they absolutely will go for the bits of sprouts and kalettes that you harvest as well as the leaves. It does make you wonder how much insecticide farmers must use on brassicas to keep them so clean.

I stopped growing brassicas because of the white fly. Never had them in the greenhouse since.

They're only really a problem on brassicas you eat the leaves of i.e. kale, which they seem to adore (and kalettes which are a kale x sprout cross). Which is one of the reasons why I've stopped growing full size kale and just harvest them as baby leaves for salads (also I don't really like big kale leaves, too tough and chewy). We harvest the asian greens they're on in the greenhouse regularly so they don't get time to build up numbers and cover the underside of whole leaves with their nymphs. Otherwise they're just a bit of a nuisance when they fly in your face. I find the mealy cabbage aphid much worse because they can badly stunt the growth of plants they feed on and they absolutely will go for the bits of sprouts and kalettes that you harvest as well as the leaves. It does make you wonder how much insecticide farmers must use on brassicas to keep them so clean.

Right with you there on commercial crops and insecticide, how on earth do farmers keep away carrot fly and, as you say, all the nasties that attack brassicas.

The farmers around here often grow carrots and I've never seen them netted. They do put massive swathes of enviromesh type stuff over young lettuces and spinach in spring, probably to shield them from bad weather and keep birds and animals off. There are systemic insecticides which they can treat seed with, so only the insects which feed on the young plants are harmed. They also use pyrethroids (like the stuff in fly killer aerosols) as sprays but they only kill the adult flies and don't control the larvae.

I stopped growing brassicas because of the white fly. Never had them in the greenhouse since.

They're only really a problem on brassicas you eat the leaves of i.e. kale, which they seem to adore (and kalettes which are a kale x sprout cross). Which is one of the reasons why I've stopped growing full size kale and just harvest them as baby leaves for salads (also I don't really like big kale leaves, too tough and chewy). We harvest the asian greens they're on in the greenhouse regularly so they don't get time to build up numbers and cover the underside of whole leaves with their nymphs. Otherwise they're just a bit of a nuisance when they fly in your face. I find the mealy cabbage aphid much worse because they can badly stunt the growth of plants they feed on and they absolutely will go for the bits of sprouts and kalettes that you harvest as well as the leaves. It does make you wonder how much insecticide farmers must use on brassicas to keep them so clean.

My husband absolutely loves "greens" - cabbage, kale and swiss chard. Kale takes forever to cook.  I do like some greens but often end up added extra calories -  in a sauce, gratin, bit of cream et   my boys grew up on roasted kale seaweed - with a little honey.  One year I grew january king on one side of the greenhous/kale the other - There were 1000's in there - never again.
I clean out the greenhouse twice a year now - completely empty it before starting again for Autumn.  And am totally ruthless with kicking plants out. 

Fungus gnats were the worse thing Ive had to get rud of. Seedlings just couldn't get going and it was pretty heartbreaking.

I stopped growing brassicas because of the white fly. Never had them in the greenhouse since.

They're only really a problem on brassicas you eat the leaves of i.e. kale, which they seem to adore (and kalettes which are a kale x sprout cross). Which is one of the reasons why I've stopped growing full size kale and just harvest them as baby leaves for salads (also I don't really like big kale leaves, too tough and chewy). We harvest the asian greens they're on in the greenhouse regularly so they don't get time to build up numbers and cover the underside of whole leaves with their nymphs. Otherwise they're just a bit of a nuisance when they fly in your face. I find the mealy cabbage aphid much worse because they can badly stunt the growth of plants they feed on and they absolutely will go for the bits of sprouts and kalettes that you harvest as well as the leaves. It does make you wonder how much insecticide farmers must use on brassicas to keep them so clean.

Right with you there on commercial crops and insecticide, how on earth do farmers keep away carrot fly and, as you say, all the nasties that attack brassicas.

Yes - flowers too! 
I love making cakes and I've seen a huge increase in people using fresh flowers for decoration.

I dont believe that many people who use flowers have a clue that shop bought can have tons of stuff sprayed on them to keep them insect free - then they stick them all over a cake.