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Starting Tomatoes from Seed

tomatoes

There are many different ways of growing tomatoes, both in the greenhouse and outside. I will cover the varieties I grow for myself and my observations and methods.

Sowing the seed

I start off all my tomatoes in the same way between late February and early March by sowing thinly into a standard potting compost in small 2½” pots, lightly covered with compost and placed in a heated propagator. A warm windowsill will also suffice.

My experience has been that starting tomatoes off too early is counter-productive. The day length is too short and the light intensity too low to get strong seedlings. Consequently the seedlings become 'drawn' - long, thin spindly shoots trying to get out of the shade into the sunlight, which is just not there. Although you can rescue these by planting deeply, later sown seeds seem to catch up and even overtake the earlier.

Also, when moved into the greenhouse, it is harder to maintain a reasonable temperature – unless you can afford a heated greenhouse. Even in mid-March you need to watch out for really cold nights. In Britain we hardly have climate but we do have weather!

To defend against cold nights I place horticultural fleece over the seedlings, using some short sticks to keep the fleece from pressing down on the seedlings.

This year (2005) has been pretty variable in terms of temperature and particularly cold in March so my tomatoes have not been the best. However, I'm hopeful of a decent enough crop for our needs. I kept the seedlings indoors in the window as the outside temperature was quite low and they did get drawn to the light.

Potting On the Tomato Seedlings

When these have germinated and are about an inch high, I move them into individual modules in a seed tray, which are grown on in the greenhouse. Pots indoors will do if you do not have a greenhouse.

When they outgrow the modules, I select the best and move them on to 3" pots. I always 'plant deep', about half way up the stem at each stage. This encourages root formation, which the plant will need to supply the demands I am going to make upon it.

You could probably cut out the module stage – but I always expect to lose a few seedlings on transplanting so this gives me 'spares'. Moving from modules to pots does not place any strain on the plant so I do not plan on losses at this stage.

Some particularly vigorous varieties may need to move to an even larger pot before they reach their final position.

You can, of course, buy tomato plants from nurseries but I prefer to grow my own from seed as you can generally only buy the most popular varieties this way.

Moving the tomato seedlings on.	Click Image for larger version
In this picture you can see the seedlings in the small pot - they are pulled from the low light level in the house. The module insert is filled with compost.
Having removed the seedlings from the pot, dib a hole into the compost and drop the seedling in. By planting deep the plant is encouraged to form more roots
Finished! Six healthy tomato seedlings ready to grow on
Due to cold weather in March 2005, the modules with the tomato seedlings are being brought on in the window instead of the greenhouse. Unfortunately they do get drawn by the lower light level.