Here it isn't daylight hours it is temperature that is the deciding factor. One thing I have trouble getting my head around is a climate with temps in zones 7 or 8 or 9 , yet you have to wait until the sun reallly starts to shine brightly. When I was doing commercial hydroponics many years ago we could grow tomatoes in the winter under low light conditions using light reflectors, (tinfoil) although this was in the Houston area and a lot different from the UK. But I still can't see why one couldn't grow seedlings. I guess I would just have to be there and see.
Leggy tomatos.............unless they are topless what difference does it make if they are tall? Don't you plant your tomato plants almost up to the first set of true leaves anyway? I know there have been discussions about planting leggy tomatoes on their sides or at an angle or extra deep, supposedly allowing for more root growth. I have done it all and as far as I have observed in more than 60 years of gardening, that there is not that much difference in ROOT growth between a short stocky plant and a tall leggy plant, even applying mycorrizae to both. Most of the difference being that a leggy plant is more prone to wind damage and when the plant grows taller it may need staking in the case of determinates but the plant will still grow out of the tall skinny stage. Otherwise you will stake inderminates anyway. I am not trying to argumentative but I just can't see why. Perhaps living in South Texas clouds my thinking
As you can see I'm in zone 9 but the weather here is pretty much the same all year round and summer temperature rarely gets above 23C/73F, winter temperature rarely below 3C/37F. Temperatures on mainland Britain differ slightly to my own, we must remember my small island is warmed by the surrounding sea. There's also the fact I live in the north west of the country which alters daylight hours. Starting tomatoes from seed before early March means they will definitely be leggy unless grown under lights. Although daylight hours improve in length the weather patterns remain pretty constant (although we do get more sun in the summer) which cuts down the light necessary for the plants to grow well. This autumn/winter has been particularly bad with no more than approximatel twenty four hours of sunshine since the beginning of November, very depressing and not set to improve anytime soon.
The British tend to grow indeterminate tomatoes and keep them uniform by pinching out (stopping) the main stem at the preferred height, We also take out sideshoots so that the plant concentrates on growing fruit rather than growing more stems. If the plants are leggy then there will be fewer branches by the time they are stopped, therefore less fruit. Our growing season is also shorter with less heat so there is no point in growing larger plants as the top will not be producing fruit by the end of our season.
I grow my tomatoes in a cold greenhouse after starting the seeds off in an electric propagator and growing them on indoors until April when they are ready to be moved outside. Even here there is a risk of frost before the middle of May. I grow all my tomatoes in the greenhouse as they are not successful outside in the climate/weather conditions here. I grow them in buckets in compost because my soil is sandy and contains very few nutrients. I 'stop' the plants at approximately 5ft and they are staked with canes. Most plants will be fruiting and ready to pick around mid to late July with the season finishing usually around late September. At the start of September the light and heat is reducing so I strip the plants of their leaves to help remaining fruit ripen.
The green tomatoes here are Manx Marvels, red when ripe.
These tomatoes are Golden Pearl, orange when ripe and slightly bigger than a cherry tomato
Golden Pearl, very sweet when ripe.
Manx Marvels with leaves stripped below. The fruit varies in size as it is a vintage tomato that was grown for the first time in 1948/49 It's a rare tomato that was brought back from extinction by a scientist here in Britain after finding the seeds in an American seed bank. After growing and producing further seed he returned them to the islands people to propagate. There are now growers around Britain too.
