Simple overview

Chilli and capsicum are the same plant family (Capsicum), grown for their fruit — but 'capsicum' usually means the big, sweet, mild types and 'chilli' means the hot ones. They are SOLANACEOUS (like tomato and eggplant), NOT cucurbits, so their pests, diseases and registered chemicals are different from your cucumbers. Around Darwin they can be grown almost all year, and they are a good beginner trial crop: compact bushes, picked over many weeks, green or left to colour.

Best climate

Warm-season crop that suits the Top End; around Darwin capsicum and chilli can be grown all year. They dislike waterlogging and prolonged leaf wetness (disease risk). Very hot spells can cause flower drop and sunburnt fruit.

Best season (Darwin / NT)

Around Darwin, capsicum and chilli can be grown almost all year; the milder, drier months give the cleanest fruit. Confirm the best window for your block with the NT capsicum/chilli pages and the Darwin/Katherine sowing calendar.

Soil and beds

Raised, free-draining beds at pH ~6.0–6.5. Capsicum are sensitive to calcium supply, so even soil moisture and adequate calcium matter; gypsum raises soil calcium without changing pH. Plastic mulch + drip is common.

Drainage

Needs good drainage — wet feet invites phytophthora root/crown rot and damping off.

Water

Keep soil moisture EVEN — swings in moisture (plus poor water quality) trigger blossom-end rot even when soil calcium is adequate. Avoid wetting the leaves.

Feeding (fertigation)

Nitrogen for early vegetative growth, then more potassium as fruit size and colour. Calcium is central to fruit quality (blossom-end rot). Boron and magnesium support flowering and set. Base the program on soil/leaf tests.

Foliar feeding

Calcium and boron are commonly applied around flowering/fruit set — but blossom-end rot is mostly fixed by even watering, not by sprays alone. Follow the product label rate.

Most important nutrients

Nitrogen (early growth), potassium (fruit sizing/colour), calcium (fruit quality/blossom-end rot); plus magnesium and boron.

Common deficiencies

Calcium (blossom-end rot — often a watering problem), boron, magnesium, potassium.

Pests in plain words

The big one is THRIPS, because Western Flower Thrips (and other thrips) spread tomato spotted wilt virus (TSWV) — infected plants don't recover. Also watch aphids (spread other viruses), whitefly, two-spotted mites, broad mites, caterpillars/heliothis, fruit fly and, in warm soil, root-knot nematodes. Mealybugs and mirids occur too.

Diseases in plain words

Bacterial spot and anthracnose (worst on ripe/coloured fruit) are the main wet-weather diseases; powdery mildew, cercospora leaf spot, phytophthora root/crown rot and damping off also occur. Viruses — especially TSWV (thrips-spread) and cucumber mosaic virus (aphid-spread) — are managed by controlling the insect and using clean, resistant transplants, NOT by spraying the virus. Blossom-end rot is a calcium/water disorder, not a disease.

Spacing and plant numbers

Plant spacing: 40–50 cm   Row spacing: 60–90 cm

At 45 cm spacing that is about 222 plants per 100 m row.

Harvest quality problems

Capsicum: pick firm, full-size and glossy — green from ~12 weeks, or leave on the bush to turn red/yellow (sweeter, higher value, but ties up the plant longer). Chilli: pick as fruit reach full colour for the variety. Cut (don't pull) fruit to avoid breaking branches. Store around 7–13 °C at 90–95% humidity. Coloured/ripe fruit is more prone to anthracnose — pick promptly and keep fruit dry.

Beginner mistakes to avoid

• Treating it like a cucurbit — different pests, diseases and chemicals
• Letting soil dry out then flooding it (causes blossom-end rot)
• Ignoring thrips until TSWV appears (then it is too late)
• Overhead watering (spreads bacterial spot)
• Not staking heavy capsicum plants (branches snap)
• Leaving ripe fruit on the bush too long in humid weather (anthracnose)

Scouting checklist

• Thrips in flowers and on growing tips (tap onto white card)
• Bronze/spotted leaves or ringspots = possible TSWV — rogue and check thrips
• Aphids on new growth (virus vector)
• Broad mite damage = distorted, shiny young leaves and tips
• Dark greasy leaf/fruit spots = bacterial spot; sunken fruit lesions = anthracnose
• Wilting plants = check roots for phytophthora / nematodes

Task calendar Sample — no tasks are created until you confirm a trial plan

Photos

Chemical options (APVMA only)

Live from the APVMA PubCRIS finder — registration, WHP, rate and the source badge come from the finder API at view time, never stored here. Always confirm the current APVMA label before use. Pests/diseases without a finder filter (and biosecurity diseases) are not shown here — check the label or a permit directly.

Open the full chemical finder

Fertiliser options by goal

Shortcuts into your Fertilizer Library. These filter by nutrient or use method — they are not prescriptions, and fertilisers are never pest/disease treatments unless APVMA-registered.

Open Fertilizer Library

Sources