Greenhouse Planting Calendar NZ: The Ultimate Year-Round Guide

Spring (September – November)

Spring is the best time to start seedlings for outdoor planting and to grow fast-maturing crops inside the greenhouse.

Best spring crops to plant:

• Vegetables:Tomatoes, cucumbers, peppers, beans, zucchini, eggplant
• Herbs: Basil, coriander, dill, parsley
• Flowers: Marigolds, petunias, nasturtiums

spring Greenhouse Tips:

• Keep ventilation optimal to prevent fungal diseases.
• Use shade cloth on warmer days to prevent overheating.
• Begin hardening off plants for outdoor transplanting.

Summer (December – February)

With temperatures rising, greenhouse conditions need to be carefully managed to avoid overheating and excessive humidity.

Best summer crops to plant:

• Vegetables: Lettuce, spinach, radish, capsicum, melons
• Herbs: Mint, thyme, oregano, chives
• Flowers: Sunflowers, zinnias, dahlias

summer Greenhouse Tips:

• Increase watering frequency to counteract heat.
• Use fans or ventilation to improve airflow.
• Mulch soil to retain moisture.

Autumn (March – May)

Autumn is a transition season, ideal for growing cooler-weather crops and starting winter greens.

Best autumn crops to plant:

• Vegetables: Broccoli, cauliflower, carrots, beetroot, peas
• Herbs: Sage, rosemary, lavender
• Flowers: Pansies, violas, snapdragons

autumn Greenhouse Tips:

• Start reducing watering as temperatures drop.
• Use thermal mass (like water barrels) to retain heat overnight.
• Begin planting overwintering crops.

Winter (June – August)

With shorter days and lower temperatures, winter is perfect for slow-growing crops and cold-hardy vegetables.

Best winter crops to plant:

• Vegetables: Kale, leeks, onions, garlic, Brussels sprouts
• Herbs: Winter savory, tarragon, chervil
• Flowers: Primroses, cyclamens, violas

winter Greenhouse Tips:

• Use greenhouse heaters if necessary.
• Keep doors closed at night to trap warmth.
• Use row covers inside the greenhouse for added frost protection.

January

• What to Plant: Lettuce, spinach, basil, tomatoes, cucumbers.
• What to Harvest: Tomatoes, capsicum, melons, zucchini.
• Garden Chores: Prune tomato and cucumber plants, increase ventilation.

February

• What to Plant: Radishes, coriander, lettuce, beans.
• What to Harvest: Eggplant, peppers, summer greens.
• Garden Chores: Prepare soil for autumn planting, monitor humidity.

March

• What to Plant: Broccoli, cabbage, winter herbs, carrots.
• What to Harvest: Late summer crops, peppers, zucchini.
• Garden Chores: Begin covering plants for cooler nights.

April

• What to Plant: Winter greens, onions, garlic.
• What to Harvest: Late-season tomatoes, beans.
• Garden Chores: Use row covers for frost protection.

May

• What to Plant: Carrots, beets, kale, spinach.
• What to Harvest: Brassicas, herbs.
• Garden Chores: Reduce watering, add mulch.

June

• What to Plant: Kale, onions, chervil, winter greens.
• What to Harvest: Leeks, winter squash.
• Garden Chores: Insulate greenhouse, monitor humidity.

July

• What to Plant: Garlic, winter salad greens, broad beans.
• What to Harvest: Root crops, winter greens.
• Garden Chores: Use supplemental lighting for growth.

August

• What to Plant: Early spring vegetables, peas, spinach.
• What to Harvest: Winter brassicas, chives.
• Garden Chores: Prepare soil, fertilise beds.

September

• What to Plant: Tomatoes, peppers, cucumbers, basil.
• What to Harvest: Overwintered crops, early greens.
• Garden Chores: Increase ventilation, plant seedlings.

October

• What to Plant: Warm-weather vegetables, summer flowers.
• What to Harvest: Herbs, salad greens.
• Garden Chores: Transplant seedlings, stake tall plants.

November

• What to Plant: Summer crops, fast-growing greens.
• What to Harvest: Early tomatoes, peas, lettuce.
• Garden Chores: Maintain regular watering and feeding.

December

• What to Plant: Succession planting for ongoing supply.
• What to Harvest: Capsicum, summer greens, cucumbers.
• Garden Chores: Keep shaded, improve airflow.