For growing purposes, tomato plants are divided two distinct categories according to their growth habit. ‘Bush’ (determinate) types are left unpinched and need only to be loosely tied to canes to prevent them sagging. ‘Cordon’ varieties (indeterminate), also known as vine tomatoes, need pinching out and training during the growing season to get the best results.
Left to their own devices in the British climate, cordon tomatoes will produce masses of leafy growth with some flowers and little useable fruit, but with regular care your plants will keep producing tomatoes until early autumn.
The cordon growing method refers to training the plant on a single stem, tying this into a cane, and removing all the side shoots that start to form between the stem and leaves. With plenty of light and regular dressings of tomato feed, plants will start to flower soon after the 10th true leaf has formed and will continue to produce flower trusses right up the stem. Under glass – in a porch, greenhouse or conservatory – expect to get up to six trusses of fruit for each cordon-trained plant by mid-September.
Although you can get more trusses to form, the limitations tend to outweigh the benefits, so take out the growing tip back to a leaf joint just above the uppermost truss, so that all the plant’s energy is channelled into the fruit. In favourable locations outdoors, you should aim to get around three trusses to ripen fully.
Read our guide to sowing tomato seeds.
Learn how to raise your cordon crop, below.
You Will Need
- Tomato plants
- Growing bags
Check the main stem of the cordon-trained plant is well supported by tying it to a stout cane at intervals. Tie the soft garden twine on the cane first, then tie in the tomato plant.
Use your thumb and forefinger to nip out any small side shoots developing at the base of the leaves where they meet the stem. Take care not to tear the tissue of the main stem or the remaining leaf.
Cut out any large side shoots that develop between the stem and leaves using sharp secateurs. Snip as low as possible, close to the shoot base, but taking care not to damage the plant.
Once the lowest truss of fruit has formed, you can reduce the foliage below by tracing back along the leaf stalks and cutting back to the pair of leaflets closest to the main stem.
Under glass, cut the main stem once 5-6 trusses (3-4 outdoors) have formed to channel energy into swelling and ripening the fruit. Cut back to a leaf just above the top truss.
Pot up your sideshoots
Try rooting the sideshoots that you have picked off in water, then potting them up to raise new plants.