Top tomatoes
Golden tomatoes pack many health-enhancing compounds, writes
Lthe traditional time to plant out summer vegetable seedlings — it is time to get planting tomatoes. Something I am keen to put forward is some of the heritage tomato varieties, where much work and planning has taken place. I and 12 colleagues from independent garden centres nationwide have worked with the Whanganui-based Heritage Food Crops Research Trust to bring out a new series of tomatoes under the Ican brand.
These are plants selected for their beneficial health-giving properties using the results of 2021 scientific studies.
The first tomatoes introduced to Europe were golden orange in colour and came from Mexico. The golden colour would have come from tetra-cis-lycopene, a powerful antioxidant readily absorbed by the human body.
Red tomatoes, discovered in Peru and northern Chile, contain all-trans-lycopene, which is not so readily absorbed by humans. In the course of history, as varieties of tomatoes were crossed to produce new ones to appeal to the consumer, the recessive “orange” tetra-cislycopene was removed in favour of the “red” all-trans-lycopene.
The health potential of golden tomatoes lies not just with the abilities of tetra-cislycopene, but the unique intermediate compounds that come with it, such as neurosporene and zeta-carotene, and higher levels of phytoene and phytofluene — all compounds with health benefits.
The Ican High Health Tomato range is five of the top-ranking varieties chosen from the 2021 trials for their high levels of tetra-cis-lycopene, health-enhancing properties and great taste.
❏ Moonbeam: Lovely mild flavour, prolific golf ball-sized fruit. Highest level of TCL 4.2mg.
❏ Golden Bell: A bright-orange, bellshaped fruit of medium size. 3.6mg of TCL. Good levels of phytoene, phytofluene and zeta-carotene.
❏ Golden Grape: Bite-sized golden-orange fruits that kids love. Tasty and highly attractive, great for salads. 3.1mg of TCL.
❏ Wally’s Spanish: Meaty, bright-orange beefsteak variety with great taste. 3.1mg of TCL plus the highest levels of phytoene, phytofluene and zeta-carotene.
❏ Golden Light: A good-producing and tasty low-acid Roma style tomato 7-10cm long. 3.2mg of TCL.
These tomatoes can be eaten raw or cooked and the TCL is better absorbed and stays in the body longer than lycopene from red tomatoes. You do not need to cook them but if you do, you will get even more lycopene than cooked red tomatoes.
How to grow
Tomatoes grow best in a full-sun position but sheltered from the wind. They grow best at 21-24C, do not thrive at temperatures below 10C or above 27C and do not tolerate frost.
Tomatoes tolerate a wide range of fertile and well-drained soils tending acid within a pH range of 5.5 to 7. Some lime may need to be applied to very acid soils when growing tomatoes.
The plants perform best if they are rotated with other vegetable crop. If pests and diseases are not a major problem and the soil is boosted with regular applications of compost and fertiliser then rotation may not be necessary.
Tomatoes are also grown very successfully in containers and this is another popular option.
Prepare the soil by working in Tui
Tomato Mix or other such products. Mix in the soil at least 30cm deep.
Work in tomato fertiliser before planting; tomatoes need high levels of phosphate, but low levels of nitrogen. Dressings of fertiliser such as Ican Tomato Food during the growing season are most beneficial.
The use of slow-releasing manutec tomato tablets or jobes tomato spikes I have found the most effective for the ongoing feeding of tomatoes, capsicums and cucumbers in pots and containers.
Sowing and planting
Tomato seeds planted now will produce a crop in February-March whereas tomato plants planted out now can produce ripe fruit from late December depending on weather.
For a successional crop, you may like to sow some seeds now as well as planting out some seedlings. Seed is best sown in a seed-raising mix in clean seed trays. Fill trays to about 20mm below the top then firm and level carefully.
Soak the tray and mix until it is thoroughly wet before the seed is sown and stand for a while to drain excess water.
Sow seeds evenly across the tray and cover with a 3-5mm layer of seed-raising mix.
The best temperature for germinating tomato seeds is 21 to 24C. Germination will occur at much lower temperatures, but it is slower. It is beneficial to cover seed trays with a piece of glass and paper during germination and to turn the glass over daily so as to remove any condensation.
Seedlings should be pricked out when the seed leaves (cotyledons) are fully expanded.
Before pricking them out, loosen them by sliding a small label/iceblock stick/ narrow teaspoon or similar under the roots, lift the plants by one of their seed leaves, not the stem, to avoid damage.
Only healthy seedlings should be pricked out, into a good-quality potting mix such as Tui Tomato Mix. Discard remaining seedlings. Transplant into 5-6cm pots at the two or three-leaf stage and give the seedlings ample ventilation, space and light.
They can stand short periods of low temperature as long as day temperatures don’t fall below 7C, soil temperature is about 10C and the risk of frost is over.
If necessary cover with cloches or plastic over a frame or stake supports in the early stages to provide shelter.
Routine care
Once established, tomato plants grown in containers need more-frequent watering and tomato fertiliser to complement the loss of leached-out nutrients.
Avoid watering the foliage as this may lead to fungus infection, apply water directly to the soil over the root area or use a watering can, soaker hose, micro irrigation drippers or similar.
In mid-to-late summer some like to remove the growing tip (terminal shoot) to three leaves above a fruit truss to discourage further height and encourage the remaining fruit to ripen. Laterals should be removed about once a week, beginning about three weeks after planting. They readily bend and break off from a healthy plant. Do this when the plants are dry — less risk of disease infection.
The same applies to unwanted foliage. As leaves grow older they shade one another and the fruit. Removing some improves air circulation and further reduces the risk of disease and allows more sunlight to ripen the fruit.
Grafted tomatoes can be grown without the need to have any laterals removed, because the more-vigorous root system will support the larger plant.
Gareth Carter is the general manager at Springvale Garden Centre. For more gardening information, go to