Pumpkins in Perth

Once the last frost has passed and the soil has warmed nicely, sow 2–3 seeds in small mounds of soil at your growing site, about 2.5 cm deep. Leave around 150 cm between each mound as carving varieties need plenty of room. Water in well after sowing. Sowing several seeds ensures you can keep the strongest plant at each site, giving you the best chance of producing large, well-shaped pumpkins for carving.

When the seedlings have emerged and developed their first true leaves, thin them to leave the strongest plant at each sowing site. Rather than pulling up unwanted seedlings, snip them off at soil level to avoid disturbing the roots of the plant you’re keeping. With just one strong seedling growing in each mound, the plant has all the nutrients and space it needs to develop large pumpkins.

Carving pumpkins need consistent moisture and generous feeding to reach a good size. Keep the soil evenly moist throughout summer, especially once the plants begin flowering and fruits start developing. Begin with a high-nitrogen feed to build strong vines, then switch to a high-potassium fertiliser, such as tomato feed, once fruits are swelling. Mulching around the plants helps retain moisture in hot weather.

As your pumpkin vines spread, gently guide them in the direction you want them to grow. Once several small pumpkins have started to form, select one or two of the strongest and best-shaped fruits to develop into your Halloween lanterns. Pinch out the vine tips after you’ve chosen the fruits so the plant puts its energy into swelling them. Place a piece of wood or cardboard beneath each fruit to keep the base dry and encourage even colouring. Turning the pumpkins occasionally helps them grow into a smooth, symmetrical shape—ideal for carving.

Plan your harvest so the pumpkins are ready for carving by Halloween. By mid to late autumn, usually between September and October in Perth, your pumpkins should be fully coloured with tough skins. Cut them from the vine with a sharp knife, keeping a few centimetres of stalk attached. Handle carefully to avoid bruising. Cure the pumpkins in a warm, dry place for a week or two so the skins harden properly. Once cured, store them in a cool, dry spot until you’re ready to carve.