By the summer, tomato plants should be growing strongly with plenty of leaves, flowers and developing fruits, but it’s worth taking a leaf out of the commercial growers’ books to improve your harvest and discover the secret to tasty tomatoes.
While the plants themselves might look healthy and vigorous, this in itself could lessen your overall crop, cause fruit to split and impair their flavour. To grow tasty tomatoes, you need to treat ‘em mean.
How often to water tomato plants
It can be tempting to think that a constant supply of water is crucial for tomato plants to grow and for the fruits to form. But like any plant, they need air at the roots as well as moisture if they are to grow well.
Allowing the compost or soil to dry out between watering is good practice and this means that it is a good idea not to water tomato plants every day in early summer. However, by the time the plants have grown large and filled their container with roots it may be necessary to apply water every day in hot weather.
Why cut leaves back on tomato plants
The real mean-ness comes with all that lush foliage, once the fruits start to form and swell. Then it is a good idea to reduce the leaf area on the plants so that less moisture is lost from them by evaporation. This will prevent the plants from drying out quickly in hot weather which would readily stop the supply of water to the swelling fruit. Any slow up in this supply can cause skins to ‘set’ and result in fruit splitting when the supply returns.
This is a much better way of regulating water flow through the plant, rather than continually apply water at the base. Reducing the leaf area lessens the demand for water from the leaves, allowing it to be consistently supplied to the fruits. And with such a ‘just enough’ amount of water, the sweetness and taste of the resulting tomatoes is usually dramatically improved.
How much leaf to cut from tomato plants
But it is important not to remove too much foliage and to take it off from the right place. As a rule it is best to leave all the leaves intact until the first truss of fruit has set and is swelling. At this stage, all the leaves under the truss can be reduced in size, but not cut off altogether.
Each individual tomato leaf is made up of different sections or leaflets, joined to a central rib or vein. Reducing the number of these leaflets drastically cuts down on the surface area and thus the amount of moisture that can be lost from it. This is done by cutting across the central rib of the leaf just above the bottom pair of leaflets.
The remaining portion of the leaf can continue to make sugars for the plant which are channeled into more growth and fruit production. But as they are under the developing truss, more water from the roots can flow directy to the fruit.
This technique can then be repeated further up the plant, as more trusses form. Don’t be too eager to reduce the leaves though; wait until the fruit is swelling before cutting them back.
Cutting back foliage to ripen fruit
Once the fruit on each truss has fully formed, the remainder each leaf under that truss can be cut back flush to the main stem of the plant. This will prevent water loss below the truss so that the fruits remain soft skinned without splitting as they ripen. Again, this is repeated up the plant as each truss reaches this stage.
Such foliage removal has the added benefit of allowing light to get through to ripen the fruit quickly. And it also improves air circulation around and through the plants to prevent fungal problems.
So reduce the leaves on your tomato plants and taste the difference in your crop.