Growing Tomatoes

Tomatoes are easily the most popular home grown produce. There is also something immensely satisfying about picking your own tomatoes for months on end. They produce more than other vegetables from a small space with yields of 5 kg per plant not uncommon.

Key points for success
  • Warm, sunny site.
  • Free draining soil
  • Fertilser and water

Tomatoes are warm season plants. From a spring planting they produce fruit continuously from December until the end of May. This continual crop can come from the ongoing care of tall varieties growing on stakes or supports or from the easy care method of successive plantings of dwarf varieties, every 3 to 4 weeks.

Selecting the site

Tomatoes grow best in a warm, sunny position. They should not be grown in the same area of soil for 2 years in a row. It is best to move them to a new site each year and return to each site one year in four.

The soil

Tomatoes grow in most soils, but the usual rules apply. They require good drainage, compost added to improve structure and the planting area raised in clay soils.

The plants

Tomatoes can be grown from seed or purchased as plants.
There are many varieties, with fruit which varies in size, shape, taste, colour, acidity, as well as the growing habit of the plants. So if you are a tomato fanatic try the different varieties until you find your favourite, it can be fun.

Most reliable and best yielding are ‘hybrids’ which are vigorous and have resistance to many soil fungal diseases affecting tomatoes. Alternatively, your favourite varieties grafted onto disease resistant rootstock will also perform well. (Supatoms or Graft–Toms).

New good performing hybrids include:

  • Alicante; Dynamo; Red Sunrise; for medium round fruit with good yield and taste
  • Sweet 100 is a vigorous tall variety with bunches of small cocktail size fruit which hang like grapes.

Of the older varieties the following are most popular:

  • Grosse Lisse is the most popular of older varieties. It has medium, large, round, fleshy fruit of good flavour.
  • Beefsteak is a large flat fruit, still popular.
  • Dr Walters is a large fruiting low acid variety.
  • Roma is the traditional egg shaped fleshy, non acidic tomato, popular for cooking and sauce making.

There are a number of new interesting varieties including dwarf spreading or hanging types of cocktail size tomatoes in red or yellow, which are very suited to pots or hanging baskets on the patio.

There are also a number of heirloom varieties, which are interesting. It is fun to try one or two different varieties each year.

When to plant

Being a warm weather crop, tomatoes don’t really start growing until temperatures are up to 20°C with night time minimums above 10°C. Hence in most areas they can be planted from late October onwards. (Be aware of the need to protect from late frosts). 

A later planting in December January, will ensure a good supply of tomatoes through until the end of May or later.

How to Plant

If raising from seed refer to the information sheet on seed raising. 

Plants are best planted out 50 to 60cm apart when 15 to 20cm high. Before planting add a dressing of Lime, and work ‘Tui’ General or Tomato food into the soil.  Tall varieties will require stakes or support.


Tomatoes will yield much more if they are well fed.  Hence in addition to the fertiliser applied prior to planting, commence weekly liquid feeding once the first truss of fruit has formed with Tui Tomato Food or iCan Fast Food.


Tomatoes require lots of water regularly. They must not be allowed to dry out as this drastically reduces yield. Irregular watering leads to blossom end rot, a sunken black patch on the bottom of the fruit. Water daily in hot weather once fruit has developed.

After Care

Dwarf varieties can be left to sprawl on the ground. Most varieties are tall varieties requiring staking. Hybrids and grafted varieties have much more vigour and will sustain 2 or 3 main leaders. 

Tomatoes need to be supported by tying to a stake or fence, or by planting them inside a four posted support. Most gardeners use a stake, and tie the main tomato stems to the stake at 30cm intervals. 

The main stems come from the central leader of the young plant plus the first strong lateral or side shoot.  Once these two stems are established all other side shoots (laterals) should be pinched out to keep the plant tidy and manageable. 

Pinching out the new side shoots should be done twice a week as they can get out of hand very quickly.

Pests and Diseases

Many problems with tomatoes are associated with temperature, watering and feeding.

Blight and botrytis may be a problem in cool wet seasons, and are controlled by spraying with Growsafe Free Flo Copper.

Fungus can be dealt with by spraying with Yates Fungus Fighter.

Insect pests of tomatoes are;  Aphids, white fly, tomato caterpillar, and possibly the new pest - tomato and potato psylid. Fortunately all are controlled by spraying with eco friendly Yates Mavrik.