How to grow Capsicum in Australia

Where to plant

Grow capsicums in full sun in rich, slightly acid to neutral soil that drains perfectly. Prepare the bed a few weeks ahead with compost or pelletised chicken manure, a little sulphate of potash and blood and bone. In hot, dry areas they appreciate some afternoon shade or 30 to 50% shade cloth in midsummer, which prevents sunscald on the fruit.

Cold is their enemy. Plants set back by cold soil or cold nights after planting often never fully recover, so wait for settled warmth. Rotate the bed: do not plant capsicums where tomatoes, potatoes, eggplants or chillies grew in the last few years.

• Sydney and Perth: sow indoors with warmth from July to September and plant out in September or October once frost has passed.
• Adelaide: sow indoors in August and September, and transplant in October and November so fruit sets before the worst heat.
• Melbourne and Canberra: raise seed indoors in late winter or buy seedlings, and plant out after frost, from October in Melbourne and November in Canberra. Choose early-maturing varieties.
• Hobart: marginal; plant out after the last frost against a warm wall or in a greenhouse, and expect a light, late crop.
• South East Queensland and the Northern Rivers: sow from August to January, with a second chance in late summer.
• North Queensland and Darwin: a dry-season crop, sown from April to July or August. Wet-season plantings suffer fruit rot and disease.

Choosing a variety

• Blocky bell types such as Californian Wonder ripen from green to red.
• Long, tapered sweet types such as Giant Marconi and Cubanelle crop earlier and suit cooler areas.
• Sweet Banana bears pale yellow, banana-shaped fruit over a long season.
• Mini bell types are compact and suit pots.

How to plant

1. Sow seed 5 mm deep in punnets in a warm spot, ideally on a heat mat, about 8 to 10 weeks before you plan to plant out.
2. Keep the mix moist and warm; seedlings can take up to three weeks to appear.
3. Plant out once the soil is warm and frost has passed, about 40 to 50 cm apart, or wider in cool areas so more sun reaches the soil.
4. Water in, mulch, and put in a stake beside each plant.

Watering and feeding

Water deeply and evenly, and never let the soil dry out once fruit is forming. Blossom end rot, a dark sunken patch at the base of the fruit, is caused by too little calcium reaching the fruit, usually because of uneven watering. Mulch to keep the soil evenly moist.

Feed with a fertiliser higher in potassium once flowers and fruit appear, every two to three weeks. Too much nitrogen gives leafy plants with few fruit.

Pruning and care through the year

• Tie plants to a stake as they grow; a heavy crop bends and breaks the brittle stems.
• Leave the leaves on: they shade the fruit from sunscald.
• Flowers drop in very hot weather or cold nights; fruit sets again when temperatures ease.
• In fruit fly areas, bag or net fruit soon after it sets.

Harvesting

Pick capsicums green once they are full size and firm, or leave them to ripen to red, yellow or orange for a sweeter flavour, which takes a few more weeks. Cut the stalk with secateurs rather than pulling, which can break branches. Regular picking of green fruit encourages more to set.

Capsicums keep for a week or more in the fridge, and can be roasted and frozen.

Growing in pots

Capsicums grow well in pots at least 30 cm wide and deep, and pots warm up faster than garden soil, which suits cool areas. Use a quality potting mix, a stake, and water often in hot weather, as uneven watering in pots causes blossom end rot.

Saving seed

Seed from open-pollinated varieties grows true if the plant was not near chillies or other capsicums, which can cross. Scrape seed from a fully ripe fruit, dry it on paper and store it dry. Seed from hybrid varieties will not come true.