Growing Pumpkins Organically and Variety Comparison

Pumpkins are a staple in our household, appearing in a wide variety of dishes — from simply roasted to curries, lasagna, risotto, and beef stew. We grill them, roast them, boil them for soup, and simmer them with coconut milk.

We aim to keep pumpkins in the pantry from March to November, and have discovered that the unique texture and flavour of each variety lends itself to specific recipes. Growing an assortment of pumpkins is not only decorative but also appetising.

One pumpkin plant may seem more then enough with its roaming vines. But think about those quintessential moments in high summer when you gaze over the garden with a pumpkin vine weaving its way through corn and sunflowers, cascading over beds and fences, attracting beneficial pollinators and slowly maturing big fruits - summer expression and abundance! Large pumpkin varieties can also be trellised to create a living arch over a garden path- the stems strengthen naturally to support the weight of the fruit!  

In addition to their diverse flavours, different pumpkin varieties offer varying storage options and make stunning seasonal displays. Packed with flavour and nutrition, these pantry staples are as beautiful as they are versatile.

Seed Starting for Pumpkins

We start pumpkins in large 3” soil blocks in the glasshouse. This gives a head start on weeds and ensures healthy root development. Pumpkins have deep root systems, often exceeding 1 m, and dislike root disturbance. Soil blocks allow minimal disruption at transplanting.

• Start seeds 2–3 weeks before our ideal transplant date to balance warm soil and sufficient growing days for harvest.
• With many varieties requiring over 100 days to mature - sowing is typically late October to early November.
• In cooler springs, starting in the glasshouse gives a jump start on the warm season.

Transplanting Pumpkins

• Sow 2–3 seeds per large soil block or container. Maintain temperature above 24°C.
• Thin to 1-2 plants per block using scissors to avoid root disturbance.
• Harden seedlings 4–7 days before transplanting by moving them outside to a protected spot and reduce watering.
• Transplant when nights are consistently above 15°C, using the indicated spacing for each variety.
• Handle seedlings carefully; minimal root disturbance also minimises transplant shock. 

Direct Sowing in the Garden

• Sow in late spring when soil is at least 21°C and nights are above 15°C.
• Plant 2–3 seeds per spacing interval, 1.5-2.5cm deep, depending on seed size.
• Once seedlings are established, thin to 1 plant per spacing interval.
• Protect from mice, rats, birds and snails.

Soil - Living Mulches - Companion Planting

Pumpkins are considered heavy feeders and benefit from soil that has had an autumn sown diverse green manure crop grown with well rotted manure. This offers the plant rich, biologically active soil. Fertile, well-drained soil with a pH of 5.8–6.8 is best.

Pumpkins occupy two whole bays on our small farm. We interplant them with a low lying white clover and sunflowers. Not only do the sunflowers look amazing with the pumpkin vines, they also attract pollinators. As pumpkins use so much high valued real estate, we demand that they are productive!

Pumpkin fruit development completely depends on pollination with each plant having male and female flowers. The pollen from a male flower needs to get into a female flower. This is directly related to pollinators in your garden, availability of male flowers  and climate, as too much heat or a lot of rain can damage the available pollen.

We have also had intense heat in summer and the sunflowers shade the forming fruit helping to avoid sun burn while the clover shades and protects the life in the soil and available moisture.

We have tried planting into a non-living mulch - crimping and dropping our green manure crop and planting into it. One of our main “pests’ in our coastal situation is small snails. As soon as we transplanted the pumpkins, the snails attacked.  We also need to maximise soil warmth in spring and find this occurs quicker with an incorporated green manure as opposed to just a crimped one.

We have also mulched with straw which works well to maintain soil moisture and protect the soil.

The Three Sisters

The three sisters is a companion planting guild with corn, climbing beans and pumpkin - each nurturing the other in a symbiotic relationship that benefits all. This planting guild has its origins in the domestication of squash, corn and beans is Mesoamerica over 6000 years ago with many different interpretations throughout North America.

The practical application, in a home garden might be with a flint or pop corn variety, a dried bean and pumpkins. Pumpkins are so vigorous, harvesting corn and beans for fresh eating would require tip toeing through the pumpkin vines. 

In Southern Victoria, the pumpkin patch can be a haven for poisonous tiger snakes, attracted to the ample mouse population hiding under the large pumpkin leaves. Once the canopy closes, we walk in carefully with tall gumboots.

In addition to clover, vetch, a leguminous green manure bean, can be under sown in the pumpkin. The flowers attract pollinators, the nitrogen fixing nodules work for the pumpkin and the corn, and the legume stabilise the corn in strong winds.

Finding the right combination may take some experimentation.  Here at Transition Farm, we find that under sowing lower growing living mulches in the pumpkins and maintaining beans and corn separately works better for overall crop production.

Disease Prevention

One of the best way to ensure a generous harvest is supporting the health of the plant.

• Transplant into fertile, living soil. A biologically active soil supports the plant’s own natural disease resistance — almost like a protective force-field.
• Allow space and airflow. Good spacing reduces humidity around leaves, helping prevent fungal problems. Proper spacing also allows the plants root to access all the nutrients the plant needs.  Powdery mildew commonly strikes at the "finishing" stage of fruit formation. Strong airflow greatly reduces its impact allowing a mature fruit that will store better.
• Water deeply and less often. Deep watering encourages a robust root system, which boosts resilience and keeps plants thriving through warm weather.
• Mulch the soil. A living mulch or straw layer helps retain moisture, keeps the soil cool through summer, and supports the soil biology that protects plants from disease.
• Manage plant stress early. Stressed plants are more vulnerable. Follow the above steps to provide optimum plant health and growth
• Saving Pumpkin Seed

Pumpkin varieties readily cross-pollinate. While the fruit itself will grow true to type, any seeds produced in a garden with multiple varieties will be a new hybrid. The isolation distance for pumpkin is as far as a bee will fly.

Having multiple pumpkin varieties nearby can benefit overall pollination, fruit set and overall harvest, but to save seed that is true to a specific variety, hand pollination may be required.

Steps for saving true-to-type pumpkin seed:

1. Tie flowers before they open: Select a female flower (attached to a small fruit) and a male flower (on a tall stem). Tie each closed flower to prevent unwanted pollination.
2. Check readiness: When the flowers naturally begin to open, the plant signals that pollen is viable and the female flower is ready.
3. Collect pollen: Carefully remove the male flower and peel back its petals to expose the pollen-laden stamen.
4. Pollinate: Gently rub the pollen onto the stigma of the female flower, leaving the fruit attached to the vine.
5. Retie the female flower: This ensures no other pollen contaminates the seed.
6. Mark the fruit: Label the fruit to ensure harvest of true to type seed!

Harvest

Harvest when fruits are full size and have a deep rich colour and hard rinds that can’t be easily dented with a finger nail. We also look for dryness in the stem - the plants indicator that it has finished maturing the pumpkin. Changing colour of the “ground spot” or general tanning or a slight terracotta colouring in the skin is also a sign.

To harvest, cut stem at least 5-10 cm from the fruit: a short or broken stem can lead to rot. Cure after harvest by keeping in a warm, dry location for a few days.

Storage

Store at 10-12°C with 55-75% relative humidity and good air circulation.  Red Kuri and Honeynut do not need curing, but will not store as long as other varieties.

We have created this concise Pumpkin Comparison Chart offering insights into each variety we offer. Click on it to read more...