Stress – mild stress that is!
Any action that causes mild stress to a tomato plant will encourage it to produce tomatoes more quickly, that is, become more generative than vegetative. It’s one reason why branch removal, by pruning leaves and trusses is a way of encouraging fruit to grow and ripen early.
We want a plant’s energy directed to the fruit and not the leaves – but leaves produce sugars and are necessary too, so a balance is required in order to achieve the best results … plant vigour and plenty of tomatoes!
Getting the balance right between leaves and fruit (vegetative and generative), through the life cycle of a plant, is a science in itself and is best done by observation. However, here are a few tips to get started.
- Too many leaves will keep a plant in its vegetative state and reduce the number of fruit it produces.
- Too few leaves will reduce the amount of energy a plant has and may also reduce the sweetness of the fruit – especially if leaf branches are removed nearest to developing trusses before the toms have ripened.
Leaf Branch Removal – for tall varieties
- Remove leaf branches up to the first truss.
- If there are three leaf branches between two trusses, the middle branch can be removed.
- When a truss is ripe, all branches below the ripe truss can be removed.
The following is based on a UK season.
How many fruit per truss?
It depends very much on the variety and growing conditions.
A medium size variety that has struggled outside may only produce six tomatoes on the first truss. A vigorous grafted variety such as Elegance, also a medium variety, may produce around twenty.
Your plants will show you by the amount of fruit that are of a reasonable size on each truss. You can remove the stragglers on the end and any extra flower shoots.
From a vigorous cherry variety, you could get around fifty tomatoes on a truss in a good season!
Number of trusses per plant
Four to six outside – five to eight under cover
This also depends very much on the size of fruit and vigour of plant.
I would grow four trusses (maximum) on a large variety but seven or eight on a cherry.
When to remove the growing tip
Growing tips should not be removed until the first truss has set fruit and the plant is well into its reproductive stage.
The reason for this is that as soon as the growing tip is removed, nitrogen is redirected back down the plant and will delay fruiting.
The growing tip should be removed two leaf branches above the top truss.
It’s been an unusual week with record temperatures posing a challenge or two for us tomato growers – it’s not just the plants that are slightly stressed!
Pruning Leaves and Trusses was originally a Tomato Growing Newsletter.