Feeding those lovely plants
If the plants growing in a well prepared greenhouse border soil, they will be happy without additional feeding until the tomatoes on the first truss are the size of small marbles. At this stage start feeding with one of the available tomato liquid feeds, applied every seven to ten days in accordance with the instructions on the label.
I have to admit that I never used any fertilizer from the shops, always made my own. I will tell you how, but first I have to warn you that this fertilizer only suitable for plants grown in the soil. For those plants in growing bags or pots I strongly recommend a special tomato fertilizer from the shop.
Making your own liquid feed:
It is an old traditional method used widely for many years and in my experience it does work, I always have beautiful, strong growing plants and extremely tasty fruits.
Collect some stinging nettles (Urtica dioica) and/or some comfrey (Symphytum officinale), if you have both that is the best. Place the leaves into a bucket or some container poor some water over it, at this point you might need something on the top to keep the leaves under water. Cover the mixture and leave it for about 7 days. The leaves will rot down and you will have a smelly liquid feed. Judging by the smell of it, you will think that it has to work, but trust me it does.
Dilute the mix until the feed becomes sort of light green colour and water your plants with it once a week. Be aware it will be smelly, but it will do your plants good and you save money! And you can use on any old fruiting veg not only tomatoes, give your aubergines and peppers a treat too.
Sub Arctic Plenty, One Of The Earliest Tomatoes
Stopping the plants
As you all know for sure there are two main type of tomato plants considering the growing habit of the plants. Bush (determinate) type tomatoes do not need side shoot pinching and all that, just let them grow as they wish and they will provide you with plenty of fruits. The cordon (indeterminate) types need more care and attention.
Pinch out the side shoots from the start, these are the small new growth which appears in the leaf joints. This way you will reduce the plant to one main stem, and will encourage vertical growth, which is necessary for the plant to develop nice long trusses and tasty fruits.
Stop the vertical growth by pinching out the very top of the plant, when the plant has five trusses. This is just a general guide, in colder climate you should stop the plant at 4 trusses and in a warm climate, especially in a greenhouse you could get away even with six.
Removing The Leaves As The Fruits Ripen
It is believed by many gardeners that leaf removal will help the fruit to ripe more quickly by exposing the tomatoes to the sun. In fact, the speed of ripening depends on the prevailing temperature and not on direct sunlight. Direct sun on the fruits can be positively harmful, especially in a greenhouse, by overheating them and turning them a bolchy, orang, sometimes with a hard, green ring at the stalk end, known as green back.
The leaves are the factory where the sun’s energy is used to convert the elements into food for the plant. It is sort of a sabotage to remove the leaves from the tomato plants. Nevertheless, you should break off the first few lower leaves at the base of the plants as they wither and brown, this will help air circulation and lower the risk of disease that might develop in the rotting vegetation.
In the greenhouse too it is a good idea to remove the lowest leaves, they will be shadowed by more vigorous growth from above anyway. These early leaves may be whithering and therefore becoming more susceptible to rotting and disease. Removing them will also make it easier to get to the container for watering.
You may also find that the foliage on greenhouse plants becomes very thick. In these circumstances, to reduce the risk of fungal disease developing in the still, trapped air, remove a couple of leaves here and there from each plant, to open them out a bit and let the air circulate freely.
Curly Tomato Leaves
If you have a small greenhouse you may find that your plants have curly leaves. It is due almost entierly to the big contrast between day and night temperatures. The plants make a surplus of food during the warmth of the day, but cannot absorb it at night because the low temperature slows down their biological activity. The result is a stop start growth pattern wich produces the curly leaves. This is not such a problem with outdoor tomatoes, where the day and night temperature range is not so great.
Summer temperature control is not easy in a small greenhouse where night temperatures may plunge to below 10 Celsius, then during a sunny day may easily reach to 35 Celsius. To cool the plants by day, cover the glass with plastic shading cloth or paint the glass with shading paint. An other way to cool down the greenhouse is to sprinkle water on the path inside, but be careful not to overdo it, as excessive humidity can encourage fungal diseases.