Goldfields gardens: time to plant those summer tomatoes

Lilian WaltersKalgoorlie Miner
Red tomato - stock photo
Camera IconRed tomato - stock photo Credit: Getty Images/Image Source

Tomatoes,Solanum lycopersicum, originated in Peru.

Columbus is often credited with bringing them to Europe, but most historians believe seeds travelled in Spanish ships leaving Mexico in the 1500s.

Many modern hybrids are bred specifically to be machine-harvested green and gas-ripened. Their tough skins are bruise and disease-resistant.

Home-grown, sun-ripened tomatoes have higher sugar content, remain on the bush until perfectly ripe and burst with flavour.

Grow tomatoes in full sun. They appreciate afternoon shade in summer (greater than 35C). Tomatoes have a long growing season (four months at greater than 20C), but struggle in temperatures greater than 38C, which affect pollen production and flowering.

What to plant this weekend

  • Eggplant
  • Cucumber
  • Broccoli
  • Beans
  • Zucchini
  • Chilli
  • Cabbage
  • Leek
  • Radish
  • Beetroot
  • Lettuce
  • Spinach
  • Chokos

Tomatoes are gross feeders. Dig in compost, aged manure and worm castings. Add grey sand or bentonite clay to improve soil texture. A pH 6.5-7.2 is ideal. Overly acidic soil causes blossom-end rot. Add lime.

Plant seeds 5-7mm deep from September to December. Thin seedlings. Never replant in the same spot. Tomatoes self-seed readily. Stagger planting to extend picking season.

Save time by planting seedlings. Leave punnets on the bench for a week. Only water twice. Make sure they’re root-bound and wait for them to flower before planting.

This harsh start activates early flowering/fruiting as a survival mechanism. Tomatoes planted into rich soil before flower-set delay fruiting and focus on growing long stems and lush leaves. Add blood and bone to each seedling hole to strengthen developing root systems.

Plant seedlings deep so the plants grow roots out of the stems. The better the root-system, the more vigorous the plant.

Tip of the week

  • Try an heirloom variety: Mortgage-Lifter, Green-Zebra, Black-Russian, Lemon-Drop, Amish-Paste, Granny’s Throwing Tomato, Aunty Ruby’s, Thai-Pink-Egg

Most varieties require support to stay upright, stop them smothering neighbouring plants, and keep fruit off the ground. Stakes, cages and trellises are best erected before planting to avoid damaging delicate roots.

Train vines on to supports. Tie-down with old pantyhose. Pinch out growing tips to limit growth. Remove lower leaves so disease doesn’t spread with water splash.

Tomatoes are thirsty plants and need regular deep-watering. Dry periods cause fruit to drop and overwatering leads to splitting. Irregular watered results in poor production and haphazard delivery of nutrients. Blossom-end rot, fruit fall, woody fruit, weak stem tissue are all related to watering inconsistency.

Pea-straw, lupin or Lucerne mulch keep weeds out and water in. Top-up as mulch decomposes. Push mulch up to the main stem, to encourage supplementary feeder roots and increased fruit production.

Don’t over-fertilise with nitrogen. Lush growth comes at the expense of less fruit. Fertilise with high-potassium blends when planting and liquid-fertilise every two weeks with seaweed-tonic, fish-emulsion or compost-tea. Tomatoes benefit from Epsom salt drenches. Apply ½ handful of potash fortnightly for better flavour and improved disease resistance. Water potash in immediately

Pick fully-coloured tomatoes. Best before the fruit is soft to the touch (8-17 weeks). Immature tomatoes ripen at room temperature. Pick often and regularly. If frost threatens or you’re going away harvest unripe tomatoes.

To deter pests plant garlic or basil; check regularly; dust monthly with sulphur; practise crop rotation; space plants to receive adequate sunlight and airflow; and encourage beneficial insects.

Don’t plant tomatoes after potatoes, eggplant or capsicum, and rotate yearly. Tomatoes suffer from looper caterpillars, tomato russet mites, bacterial canker and fusarium wilt. Companion plant with marigolds, calendula, thyme and basil.

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