Eggplants — or aubergines, as they’re often called — are a sun-loving, heat-hungry crop that can be tricky to grow outdoors in many parts of Aotearoa. But with the right setup — especially in a greenhouse — they can become one of the most productive and rewarding vegetables in your garden.

This in-depth guide covers everything you need to know about growing eggplants in New Zealand, with a special focus on greenhouse growing, which provides the warmth, consistency, and protection these plants need to thrive.

Why Grow Your Own Eggplants?

Eggplants aren’t always easy to find fresh or chemical-free in stores. Growing them yourself offers several advantages:

• Highly productive – One plant can produce 5–10 fruit or more under good conditions.
• Versatile in the kitchen – Use in stir-fries, curries, moussaka, on the barbecue, or roasted.
• Better taste and texture – Especially when harvested young and cooked fresh.
• Access to unique varieties – Grow rare and heirloom types you won’t find at the supermarket.
• Far better results in a greenhouse – More consistent heat and less exposure to pests and wind.

Best Eggplant Varieties for New Zealand Conditions

For Outdoor Growing

• Black Beauty – The classic deep purple aubergine; great for warmer northern regions.
• Rosa Bianca – A beautiful Italian heirloom with mild, creamy flesh.
• Tsakoniki – A striped Greek variety that matures relatively quickly.

For Greenhouse Growing

• Bonica F1 – A hybrid that fruits early and heavily, perfect for protected conditions.
• Ping Tung Long – Long, slender, and fast-growing — great in pots and greenhouse beds.
• Slim Jim – Compact and ideal for container growing in a sheltered spot.

Greenhouses provide eggplants with the warmth, shelter, and long growing season they prefer. If you’re serious about growing eggplants in New Zealand, a greenhouse is the way to go.

When to Plant Eggplants in New Zealand

• Outdoors: Late October to early December, once all risk of frost has passed.
• In a greenhouse: From August through to January — earlier starts and longer harvests are possible.

Because eggplants are frost-tender and relatively slow to mature, greenhouse growing offers a major advantage by extending both ends of the season.

Preparing the Soil for Eggplants

Eggplants prefer free-draining, fertile soil with plenty of organic matter.

Step 1: Sun and Shelter

• Choose a sunny, north-facing spot with shelter from wind.
• In a greenhouse, position plants to make the most of the light and airflow.

Step 2: Soil Enrichment

• Dig in compost, aged manure, and a general-purpose vegetable fertiliser before planting.
• Ensure your soil pH is around 6.0–6.8 — slightly acidic to neutral.
• Avoid fresh manure or overly nitrogen-rich feeds, which can encourage leaf growth at the expense of fruit.

If planting in containers inside a greenhouse, use a premium potting mix with added slow-release fertiliser and compost.

How to Plant Eggplants (Step-by-Step)

Seed Raising

• Start seeds indoors or in a heated greenhouse 8–10 weeks before planting out.
• Maintain a soil temperature of 21–26°C for good germination.
• Harden off seedlings before transplanting into beds or pots.

Transplanting

1. Plant seedlings around 50–60 cm apart.
2. Bury the stems slightly deeper than they were in the seedling trays to encourage strong rooting.
3. Mulch well and water in thoroughly.
4. Stake or cage your plants early, as fruit can become heavy.

Caring for Eggplants

1. Watering

• Eggplants need consistent moisture — never let them dry out.
• Water deeply but less often, and avoid wetting the leaves.

2. Feeding

• Once flowering begins, feed every 2–3 weeks with a liquid fertiliser high in potassium to support fruiting.

3. Pruning

• Remove early side shoots and suckers to focus energy on fruit production.
• In a greenhouse, thin out some leaves to improve airflow and reduce disease risk.

Common Issues and How to Prevent Them

1. Poor Fruit Set

• Likely cause: Lack of pollination.
• Solution: In greenhouses, gently shake plants or use a soft brush to hand-pollinate flowers.

2. Yellowing Leaves or Stunted Growth

• Could be due to overwatering, cold roots, or nutrient deficiencies.
• Ensure warm, well-drained soil and feed regularly.

3. Aphids or Spider Mites

• Greenhouse pests thrive in hot, dry conditions.
• Keep humidity levels up, introduce beneficial insects, or use organic pest sprays.

4. Blossom End Rot

• Caused by calcium deficiency or uneven watering.
• Maintain even moisture and consider using a liquid calcium foliar spray.

When and How to Harvest Eggplants

Eggplants are ready to pick when they are:

• Glossy and full-sized (but not oversized)
• Firm to the touch, with skin that springs back when gently pressed

Use clean secateurs to cut fruit with a short length of stem. Don’t wait too long — overripe fruit becomes bitter and spongy.

In a greenhouse, you may be able to harvest from late spring through to mid-autumn, especially in warmer regions.

How to Store Your Harvest

• Store at room temperature, not in the fridge — they don’t like the cold.
• Use within 3–5 days for best flavour.
• For longer storage, slice and freeze after roasting or grilling.

Why a Greenhouse Makes All the Difference for Eggplants

Eggplants thrive in warmth and hate cold wind, temperature fluctuations, and soggy soil. A greenhouse offers:

• Longer growing season — Start earlier, harvest later
• Protection from wind and cold snaps
• Better control over water, light, and airflow
• Far fewer pest and disease problems

If you’re in a region where summers are unpredictable or nights are cool, a greenhouse can be the difference between a struggling crop and a thriving one.

Take a look at our range of premium greenhouses — whether you’re growing in raised beds, large pots, or full tunnel houses, we’ve got a structure that fits.

Final Thoughts

Eggplants aren’t the easiest veg to grow in New Zealand, but with the right tools, timing, and care, they can become one of the most productive crops in your garden. And if you’re ready to give them the conditions they need — especially warmth — a greenhouse can dramatically improve your results.