Robin’s guide to growing tomatoes


Robin Gale-Baker, from Sustainable Macleod discusses how to grow tomatoes. This is one of a series of articles she has written about growing various veggies (see right hand sidebar). She has also written a number of articles about growing various herbs, growing various fruit trees and general growing techniques.

Also, read Helen Simpson’s guide to growing tomatoes.

Additional material from Guy’s tips: reisetomate tomatoes

The picture is of a variety of tomato called reisetomate, which I have been growing this year. Each of the bulbous bits is like a whole tomato and you can pluck them off and eat them individually. A bit like taking segments off a mandarin. It’s actually rather tasty.

‘Reisen’ means ‘to travel’ in German. Apparently, the Germans call this tomato ‘the traveller’ because it can be torn apart one piece at a time without a knife while on a journey.

Tomato plant spacing

At the start of this warm season, my wife and I set up two identical raised beds for growing tomatoes. Let’s call them ‘neglect’ and ‘nurture’. Each bed had 8 tomato frame cages, with each bed growing the same 8 varieties of tomato. In the ‘neglect’ bed, there were 2 tomato plants per cage, no removal of side shoots, and no bird netting. In the ‘nurture’ bed, there was 1 plant per cage, regular maintenance, bird netting and the quiet singing of sweet lullabies. The question being investigated was the extent to which, in terms of tomato yield, the nurturing would offset the halving of the number of plants.

The results were rather different for the different types of tomato. For the large, beefsteak tomatoes, the ‘nurture’ bed yielded more tomatoes, even with half the number of plants, and they were better quality and larger – a major win for the ‘nurture’ bed. For the small tomatoes (say tigerella and below), neglect had less of an effect and the ‘neglect’ bed yielded more (although not twice as many) fruit and of similar quality – a win for ‘neglect’. Finally, for the sauce tomatoes (San Marzano and Roma), many in the ‘neglect’ bed, but none in the ‘nurture’ bed, suffered from blossom end rot – a win for ‘nurture’.

So, in conclusion, large beefsteak and sauce tomatoes should both be grown in ‘nurtured’ beds where the plants are widely spaced (i.e. 1 plant per cage). Small tomatoes are more tolerant of ‘neglect’ and close spacing (e.g. 2 plants per cage).

Top hints for growing tomatoes
  • Plant tomatoes deeply – at least half way up their stems (you can leave the lower leaves on or twist them off). Deep planting anchors the plant; the buried stem will put out roots, taking up more water and nutrients and producing more fruit.
  • Always keep tomato roots moist otherwise the plant will begin to die.
  • Stake your plants or use a tomato cone to prevent wind damage and breakage.
  • Choose heritage tomatoes and save seeds from the fruit for planting the following season.
Positioning tomato plants

Full sun. Choose the third hottest part of the garden for tomatoes, reserving the hottest for eggplants and capsicums.

Soil preparation

Dig over soil with a fork, loosening it and breaking up clods to a spade’s depth. For a 2 x 1 metre bed dig in a barrow load of compost, a bag of cow manure and 2 handfuls of blood and bone. 4 – 5 handfuls of gypsum will also add calcium and break down clay. Add some potash, and sprinkle this around each plant. Add potash again at the time of flowering.

Planting and spacing tomatoes

Sow seeds in punnets and plant out as seedlings. Start raising seeds in June and plant out in September. Protect seedlings if frost is expected. To get a head start, plant seedlings into large pots with lots of compost, and plant well established plants out when you are certain frosts have passed. Plant out seedlings 1 metre apart in rows 1 metre apart. As the plant grows, remove lower leaves. Once the lower 30cm of the stem is free of leaves, the likelihood of spores jumping from the ground onto the leaves and moving upward, infecting the plant with septoria, is much reduced.

Planting tomatoes in pots

Tomatoes can grow well in pots. Use a good quality potting mix and add plenty of compost and well rotted animal manure or pelletised manure. Plant one tomato per pot in a pot at least 40cm in diameter. Stake the plant and keep soil moist at all times.


Laterals are shoots that grow between the stem and a main branch. Most people remove them but a Diggers’ experiment found that it made no difference to the quality or quantity of fruit. If you do pinch them out, insert them into some potting mix, water well and within 7 -10 days they will have roots and you will have extra plants.

Watering tomatoes

Water directly onto soil or mulch, and if mulch, make sure the soil below is moist. Water with a soft stream from the hose or watering can or with dripline. Remember to water to the roots and not the leaves, and to NOT splash soil onto lower leaves. Water seedlings at the time of planting and every second day for the first couple of weeks; thereafter water deeply twice a week. Tomatoes must never dry out and need a lot of water in summer and as fruit develops.

How to avoid blossom end rot

Blossom end rot is a condition that as the name implies, causes rotting on the underside of tomatoes. Technically, it is a result of the plant getting an inadequate supply of calcium but this is usually caused by the plant not getting sufficient water to its flowers and fruit. Strengthen the water delivery system by applying additional potash (available in packets from your nursery) around each plant at the time of flowering, and make sure you are giving the plant adequate water.

How to avoid sunburn

When there is an extreme heat event, tomatoes can burn and blister. Blisters manifest as white, soft skin blemishes. Rig up a quick shade house by banging four star pickets into the corners of the bed, drape with shade cloth or old sheets and secure with yellow star picket caps. Alternatively just drape an old sheet over the plants. Water deeply BEFORE the heat event. A well hydrated plant will not burn or wilt.

Crop rotation

Do not grow in the same place, or where other members of the Solanaceae family such as eggplants, capsicums and potatoes have been grown, for three years.

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