Summer Garden Guide - Kings Seeds

Summer is when New Zealand gardens come alive with colour, flavour and abundance. Warm soil, long daylight hours and steady growth make this the ideal season for growing food in NZ. This Summer Garden Guide from Kings Seeds brings together what to plant in summer NZ, how to keep crops productive through January and February, and simple ways to care for your garden during the hottest months. Inside you’ll find advice on veggies to plant in summer, herbs, flowers and classic Kiwi crops, plus watering tips, companion planting ideas and answers to common summer gardening questions. Written for local conditions, this guide supports gardeners searching for Seeds NZ, Best Seeds NZ, Trusted Seeds NZ and seed suppliers NZ who want reliable results all summer long.

As a New Zealand-owned family business with over 40 years of experience, Kings Seeds believes growing is for everyone. From backyard beds to balcony pots, we are gardeners too, here to help you sow, nurture and nourish through summer.

Summer Garden Vegetables

Tomatoes, cucumbers and zucchini in peak summer

By January and February, most summer vegetables are already in the ground, growing fast or beginning to fruit. This is the season of support, maintenance and gentle encouragement rather than big changes.

Tomatoes in mid to late summer
Tomatoes need consistent watering and good airflow now. If plants look lush but flowers keep dropping, heat stress may be the cause. Deep watering early in the day helps roots stay cool. Remove yellowing lower leaves so air can move freely and disease pressure stays low.

Companion plants like basil can still be tucked in if space allows, though at this point the main focus is keeping existing plants healthy rather than adding more.

Cucumbers during hot weather
Cucumbers love warmth but dislike drying out. Missed watering can lead to bitter fruit, especially in January heat. Training vines vertically improves airflow and keeps fruit straight and clean. Harvest often, even small cucumbers, to keep plants producing.

Lebanese cucumbers perform especially well when picked young and regularly. If fruit starts swelling unevenly, check watering patterns first.

Zucchini, when everything suddenly explodes
Zucchini plants tend to go from tiny to enormous very quickly. Pick fruit small and often to avoid marrow-sized surprises. If leaves look wilted in the afternoon but recover by evening, that’s normal summer behaviour. If wilting lasts overnight, water more deeply.

Vertical training can still work now if plants are young enough, though older plants are best left to sprawl with good airflow underneath.

Summer Veges that love the heat  (Capsicum, Chilli, Eggplant)

Summer is their moment

Capsicum, chilli and eggplant truly hit their stride in January and February, especially in sheltered, sunny gardens.

Chillies in late summer
Chilli plants often look modest early on, then suddenly load up with fruit. Keep watering steadily and avoid letting pots dry out completely. Colour change is the clearest sign of ripeness, though some varieties stay green. Taste one once the colour deepens to judge the heat.

Capsicum care now
Capsicum appreciates regular feeding once flowering and fruiting begin. If plants look leafy but lack fruit, reduce nitrogen-heavy feeds and focus on even moisture. Removing small inner shoots can help sunlight reach developing fruit.

Eggplant in containers or beds
Eggplant thrives in heat but sulks if roots dry out. Large containers work well in January and February because they warm quickly, though daily watering may be needed. Stake plants once fruit sets so stems don’t snap under weight.

Summer Herbs (fast, fragrant, popular)

Basil and friends are in full swing

Summer herbs are quick to respond and forgiving if harvested often.

Basil grows best when picked regularly. If flowers appear, pinch them out to keep leaves tender. Water at the soil level and provide some shelter from the harsh afternoon sun in very hot regions.

Companion planting still works now, especially around tomatoes and capsicum, though the biggest benefit in mid summer is flavour, fragrance and ease of harvesting rather than pest control alone.

Big Summer Crops (classic Kiwi gardens)

Corn and pumpkins in January and February

These crops are usually well established by now, with the focus on pollination and fruit development.

Corn care mid-season
Corn needs consistent moisture during flowering. Dry stress now can affect kernel development. Silks turning brown and cobs feeling full are signs that harvest time is approaching.

Pumpkins are taking over the garden
Pumpkin vines sprawl fast in summer. Guide them early so paths stay clear. Water deeply during fruit formation and avoid moving vines once fruit sets, as this can disrupt growth.

A hard rind and drying stem are signs that pumpkins are nearing maturity, though full ripening usually happens closer to autumn.

Summer Flowers (pollinators and colour)

Flowers that thrive in summer heat

Summer flowers bring pollinators into the garden and lift everything visually when vegetables start looking tired.

Sunflowers
Sunflowers planted earlier will be flowering now. Keep watering steadily and stake tall varieties if the wind becomes an issue. Leave spent heads to mature if you’d like to save seed later.

Dahlias
Dahlias love being picked. Regular cutting encourages more blooms and keeps plants tidy. Stake early and water well during dry spells to support continuous flowering.

What to sow now for late summer and autumn colour

While some summer flowers are already in full bloom, January and February are still a great window for sowing fast-growing varieties that flower later and keep pollinators visiting well into autumn. These are ideal for filling gaps, refreshing tired beds and adding colour when summer veg starts to slow.

Good flower choices to sow now in NZ gardens

• Calendula – quick to germinate, cheerful through late summer and autumn, and loved by bees

• Cosmos – light, airy flowers that handle heat well and keep flowering as nights cool

• Zinnias – bold colour, strong stems and excellent for cutting

• Nigella – delicate flowers followed by beautiful seed pods

• Phacelia – a pollinator favourite that improves garden diversity

• Cornflowers – fast-growing and reliable for late colour

• Alyssum – low-growing and excellent for edging beds and attracting beneficial insects

These varieties grow quickly in warm soil and don’t mind the shorter days that follow summer. Water gently while seeds establish, then allow roots to chase moisture deeper as plants mature.

Summer Garden Care 

Best time to water the garden in summer

Early morning watering reduces evaporation and prepares plants for heat. Evening watering can work where airflow is good.

Simple summer care tips

• Water deeply rather than often

• Mulch to retain moisture

• Focus water at the soil level

• Check containers & pots daily during hot weather

Watch our quick top tips reel on watering here.

F A Q

What fruit and vegetable seeds can I plant in mid-summer in NZ?

Fast-growing crops like beans, beetroot, radish, salad greens and herbs suit mid-summer planting. In warmer regions, late cucumbers and basil can still perform well.

Should I mulch my summer garden?

Mulch helps keep soil cool, reduces water loss and suppresses weeds. Keep mulch slightly away from plant stems to prevent rot.

When should I water my garden?

Morning watering is best for most gardens. Evening watering can work in dry regions with good airflow.

How do I get continuous harvests in summer?

Harvest regularly, sow small batches (succession planting) where possible and keep water and nutrients steady to avoid stress.

How do I protect plants during heatwaves?

Mulch well, water deeply and offer temporary shade for young plants. Healthy soil buffers extreme heat better.

Grow well all summer

Summer gardening is about observation, small adjustments and enjoying what’s already growing. Whether you’re harvesting daily, planting a little more, or simply keeping things alive through the heat, Kings Seeds is here with NZ reilable seeds, trusted advice and local knowledge from seed suppliers NZ who garden too. Explore our seeds with confidence and let this summer be one of steady growth, enjoyed harvests and hands happily in the soil.