How to Grow Tomatoes in Growbags or Containers

Growing tomatoes in containers, either in a greenhouse or outdoors, is an easy way to produce a good sized tomato crop in the smallest garden or patio, or even on a small balcony. Growbags, plant pots, tubs and hanging baskets are all suitable containers, but the secrets of how to grow tomatoes successfully are a sunny position, and regular watering and feeding.

Tomato Growing Containers

Almost any well drained container of 9 inch diameter or more will do, including

• Growbags. A standard growbag will take 3 cordon (upright) tomato plants or two trailing or bush plants.
• Pots. A 9-12 inch pot will take one cordon, trailing or bush tomato. A bush variety grown in an ornamental pot makes an attractive patio feature as well as providing a good tomato crop.
• Larger Containers, Barrels or Tubs. A 2 foot diameter barrel or ornamental tub will take 4 plants. Planted with one cordon tomato and 3 bush or trailing tomato plants this should yield enough tomatoes to keep the average family supplied for much of the summer.
• Hanging Baskets. Suitable for trailing or bush varieties. Plant a single plant in a 10-12 inch basket, or two in a 16 inch one.

Always clean containers thoroughly before re-using, and if they have previously been used for tomato plants, sterilise with a solution of Jeyes fluid.

Where to Grow Container Tomatoes

Tomatoes can be grown:

• In a Greenhouse. A frost free greenhouse is the ideal location for container grown tomatoes, producing the earliest and largest tomato yields. Furthermore, containers with fresh, disease free compost will normally give better crops than plants grown in ordinary greenhouse soil. Not all varieties are suitable for greenhouse cultivation.
• In a Mini Greenhouse. If you don’t have a greenhouse, a mini plastic frame like the one illustrated is an excellent alternative, perfect for 3 tomato plants in a growbag.
• Outdoors. Most modern tomato varieties can be grown out doors, but will crop later and give smaller yields than greenhouse grown plants. Site containers,pots and growbags in a bright, sheltered position, preferably in full sun.

Tomato Seeds or Tomato Plants

You really need a greenhouse to grow your own tomato plants from seed, but it’s also possible to raise them on a warm, bright windowsill.

Seed firms like Mr Fothergill’s and Suttons offer a wide choice of varieties

Sow 2-3 tomato seeds in 9cm pots in February or March, thinning to a single seedling in each pot. Grow on, harden off and plant out once all danger of frost is past.

Most people, if only growing a few tomatoes, find it easier and more economical to buy young tomato plants from a local nursery or garden centre in May. Choose compact plants with dark green leaves. Again, grow on, harden off and plant out once all danger of frost is past.

More on tomato varieties.

Planting Tomato Plants in Growbags

Only use good quality, standard size growbags. Tomatoes are hungry plants and cheap or undersized bags are a false economy. Then:

• Cut a cross the size of the rootball at each planting station (2 for bush or trailing varieties, 3 for cordons).
• Peel back the plastic and plant a little deeper than the existing pot soil level. Firm the compost and replace the plastic.
• Bury a 9cm pot up to its rim between each pair of tomato plants as a watering aid. This helps the water to get down to the roots.
• Stake and tie in cordon varieties.
• Water thoroughly.

Planting Tomatoes in Other Containers

• Fill the container to 1 inch below the rim with good quality multi-purpose compost.
• Plant the appropriate number of plants for the container into the compost, set a little deeper than the original pot soil level, and evenly spaced.
• Stake and tie in cordon varieties.
• Firm the compost and water thoroughly.

Growing Tomatoes On in Growbags or Containers

Always keep tomatoes moist, but never waterlogged. Fluctuations in watering will give poor quality fruit. Container grown tomato plants may need water twice daily in hot or windy weather.

Start feeding with a special tomato feed such as Tomorite once the first fruit have set.

Keep greenhouse-grown tomatoes well ventilated in wark weather.

Pruning Tomatoes

Prune cordon varieties to prevent excess green growth and give a better fruit crop as follows :

• Pinch out the side shoots appearing in the leaf axils to prevent excess green growth.
• Remove leaves below the first truss once that has set, and any other yellowing leaves as they appear.
• Pinch out growing tips above the fourth or fifth truss of fruit outdoors, or the sixth truss in a greenhouse.

Pests and Diseases

Tomato plants from a reliable grower, planted in good clean compost and containers, well watered, fed and ventilated should grow healthy and disease free.

Nevertheless, watch out for attack by aphids, whitefly or red spider mite. Remove and burn any yellowed, mottled and distorted leaves which may be affected by a virus.

More on tomato pests and diseases.

Additional Information

More on growing your own tomatoes.