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Pumpkins are related to zucchini and squash but take up more space in the garden. They form vines with hairy, hollow stems and large green leaves that often conceal the crop.

They are a great source of potassium, vitamins C, B and E as well as beta-carotene that is converted to vitamin A. These vitamins can help play an important role in the health of the skin.

Pumpkins are not a quick growing vegetable taking 70 to 120 days from seed to harvest. However, they can be kept for months in a dark, cool space for use throughout autumn and winter. They are great in soups, casseroles, stews or used roasted, steamed or mashed. As well as classic pumpkin soup other favourite vegetarian dishes include warm pumpkin salad and pumpkin curry.

Follow our seven easy steps to successful pumpkin harvest including tips along the way.

Seven handy tips on how to grow versatile, tasty pumpkins

When to plant and location.

When to plant.

Pumpkins can be grown in most parts of Australia. Check with garden centres and hardware stores for varieties available in your local area.

  1. Pumpkins grow through the warmer months with fruit ripening in autumn.
  2. In hot, frost-free zones, seeds can be sown year-round.
  3. In cool to cold temperate and subtropical zones, sow seeds in spring (after frost has passed) to early summer.
  4. The large seed can be direct sown or started in punnets if the soil is still cold or there is a likelihood of late spring frost.

Location.

  • Grow pumpkins in full sun or with light afternoon shade in hot climates.
  • Select a position with room for the vine to spread as vines can reach 3m across. Remember they love space.
  • Grow in beds, mounds, raised vegie beds or against a trellis. Dwarf pumpkins can be grown in large containers.
  • Good companion plants for pumpkins are those that attract beneficial insects and pollinators to the patch. These include herbs such as thyme or sage or flowers including cosmos or lavender.
  • Do not plant pumpkins in the same patch as tomatoes or potatoes as they don’t get along.

Soil.

  • Provide fertile, well-drained, slightly acid to neutral pH soil.
  • Dig in compost like Seasol Super Compost or well-rotted manure before planting or apply Seasol Liquid Compost.
  • Pumpkins love compost, and that’s why you find them sometimes growing in the compost heap. The more compost, the better.
  • In areas of poor drainage, grow pumpkins in raised garden beds.
  • A soil rich in nutrients helps build strong plants so add Seasol Plant + Soil Booster (100g per square metre) and a fertiliser such as PowerFeed Controlled Release Tomatoes & Vegetables.
  • Water in well and let the soil rest for a week or two if possible.

Step 1 – Sowing seeds.

  • In the ground, grow from seed sown directly in well-prepared, moist soil. Sow seeds in shallow rows about 2cm deep and 100cm apart, pressing the seed firmly into the soil and lightly covering it.
  • In punnets, sow seeds in shallow rows into seed raising mix and cover lightly with seed raising mixture such as Seasol Seed Raising & Cutting Potting Mix.
  • In pots, choose a pot that is 40-50cm across and sow one seed per pot. Ensure the pot has enough space around it for the vine to creep and grow or select a dwarf variety.
  • Water in well with Seasol GOLD or Seasol as this will help to increase seed germination rates. Soil should be moist but not wet, so check the soil moisture daily to ensure pumpkins seeds have the right conditions to germinate. Water if soil is dry.

Note: This is not pumpkin seeds, it’s just an illustration to show seeds being planted.

Step 2 – Germination.

  • Keep the soil or potting mix moist for the 7 to 14 days it can take for the first leaves to appear.
  • Germination is faster in warm soils, so if it’s cold and they are in pots or punnets, try a heating pad or stand the pots in a foam box for extra warmth.
  • The first pumpkin leaves to appear are called sprouts and are small and round leaves. These are not the true pumpkin leaves, but are an indication that the plant is growing.
  • Water gently and apply Seasol GOLD or Seasol weekly (mix 30mL of concentrate per 9 litres of water), as this will help to stimulate strong root development and healthy growth.
  • Check young seedlings daily for pests that may like to eat them and cover where necessary to protect them.

Step 3 – Baby pumpkin seedlings.

  • About two weeks after the seed leaves have opened, the true leaves will appear.
  • If overcrowding occurs, select the strongest seedling and remove or transplant the rest.
  • Cover bare soil around the seedling with organic mulch to deter weeds while the vine grows
  • Liquid feed with PowerFeed PRO Series for Tomatoes & Vegetables weekly to keep hungry seedlings growing strong and healthy. Mix 20mL of concentrate per 9 litres of water (standard watering can) for young seedlings.
  • Check soil moisture daily and water as needed.

Step 4 – Planting out pumpkin seedlings

  • Where plants are grown from seedlings, transplant with care when the first true leaves form.
  • Space 100cm apart and firm into the soil. Make a large, shallow depression around the seedling to capture moisture.
  • To reduce transplant stress, grow seedlings in biodegradable pots to plant directly in the soil.
  • When transplanting from seedlings that have been purchased follow the directions for planting on the planting tag.
  • Water in well with Seasol GOLD or Seasol as this will rapidly promote a strong, vigorous root system. Soil should be moist but not wet, so check the soil moisture daily before watering.

Step 5 – Pumpkin plant growth.

  • Vines can be encouraged to climb up a support or the vigorously growing pumpkin vine can be tip pruned to encourages more side growth, which can lead to the production of more female flowers. Large pumpkins formed on vines growing on a trellis may need support such as a stocking sling.
  • Keep plants well-watered especially on hot or windy days as these large, leafy plants can wilt when moisture stressed.
  • Remove weeds as they appear as they compete for space and nutrients. Mulching around each plant suppresses weeds and helps retain soil moisture.
  • Every 6-8 weeks apply another application of PowerFeed Controlled Release Tomatoes & Vegetables around the vigorous plants as they grow to produce a bumper crop of tasty pumpkins and to revitalise depleted soils. Remember to water it in thoroughly after application.

Step 6 – Pumpkin flowering & fruiting.

  • Expect flowering within six to nine weeks. Fruit forms soon after the flowers appear. Flowers are also edible but harvest excess male flower to eat so as not to reduce fruit harvest.
  •  Pumpkins have separate male and female flowers on the same plant and both are needed to form fruit. The male flower is held on a narrow stem and its centre contains pollen-coated stamens. The female flower has a small swollen base, which forms the fruit after it is fertilised by pollen from the male flower.
  • As the vine matures, fresh flowers open each day so there are enough male flowers around for bees to pollinate that day’s crop of female flowers.
  • In early summer however there may be male flowers but no females slowing fruit production until the vine matures.
  • Feed hungry plants with PowerFeed PRO SERIES for Tomatoes & Vegetables weekly. Mix 50mL of concentrate per 9 litres of water.

Step 7 – Pumpkin ripening and harvest.

  • Depending on the variety, individual pumpkins can weigh between 2kg and 9kg. Small varieties weigh just 80g-200g. Large vines can produce six or seven fruit.
  • Skin colour may change as the pumpkin ripens but as many pumpkins are dark or grey green, giving the fruit the knock test is a better guide to ripeness. A pumpkin that’s ready to harvest should sound drummy (hollow) when rapped with the knuckles. In cold areas, leave until vine dies back.
  • Most pumpkins keep well. Allow the skin to ‘cure’ or harden in the sun for a week or so after harvest, but don’t expose it to frosty conditions.
  • Undamaged pumpkins can be stored in a cool, airy spot for several months. Check stored fruit regularly monitoring for rots or damage.

Things to watch for…

  • Aborted fruit Small, immature fruit may yellow and fail to develop. This may be due to blossom end rot (a lack of calcium exacerbated by erratic watering) or lack of fertilisation if bees or male flowers are scarce. Improve watering. Warm weather as the summer progresses usually solves any problems with fertilisation but female flowers can be hand pollinated using pollen from male flowers.
  • Mildew This disease attacks pumpkin leaves late in the season causing the leaves to shrivel and die. Avoid watering foliage especially late in the day. Mildew is also kept under control by a natural predator, a yellow and black spotted ladybird that feeds on powdery mildew.
  • Leaf-eating or 28-spotted ladybird This round orange ladybird with lots of dark spots skeletonise zucchini leaves but rarely damages fruit. To control, squash egg clusters and juveniles.
  • Pumpkin beetle This small, elongated orange beetle that also skeltonises pumpkin leaves but rarely damages fruit. Squash to control.
  • Rodents Fruits may be attacked by rodents especially mice which gnaw on the skin and can damage the fruit so it can’t be stored. To keep mice away from pumpkins make a protective cage or enclosure around plants.
How to grow vegetables -pumpkins
Seven handy tips on how to grow versatile, tasty pumpkins

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