If you’ve ever seen oddly colored pumpkins lining your neighbor’s porch in the fall, chances are you’ve either spotted fake decorative gourds or the real deal – heirloom pumpkins.
These tend to be larger than traditional pumpkins, and their distinctive appearance is enchanting a new generation of growers – but where can you find heirloom seeds, how do you plant them, and what does heirloom pumpkin even mean?
Mercifully, we have the answer to all these questions and more, including some of the most well-loved varieties, steps on sprouting them, and taking them from germination to garden.
Heirloom Pumpkins at a Glance
There are hundreds of varieties of heirloom pumpkins belonging to three main species: Cucurbita maxima (the largest growing on long vines), Cucurbita pepo (producing prickly leaves and five-sided stems), and Cucurbita moschata (producing hairy leaves on stems that flare out).
Most heirlooms possess the familiar deep yellow-carrot orange flesh of pumpkin fruit, but other than that, varieties differ vastly in terms of shape, weight, color, texture, flavor, maturity rate, seed cavity size etc.
Here are some of the more popular varieties:
- ‘Cinderella’/’Rouge Vif D’Etampes’ (C. maxima) – 10-15 pound fruit, vivid orangey-red skin, flat wheel-like shape, mild flavor, maturity: 115 days.
- ‘Jarrahdale’ (C. maxima) – 12-18 pound fruit, blue/slate-gray skin, drum-shaped with rounded ribs, aromatic flesh, small seed cavity, maturity: 100 days.
- ‘Autumn Crown’ (C. moschata) – 2-4 pound fruit, flat shape, buff skin, melon-like flavor, resistant to squash vine borers, small seed cavity; maturity: 100 days.
- ‘Knuckle Head’ (C. pepo) – 12-16 pound fruit, heavily-warty skin, rounded shape, bright orange, sweet flavor, maturity: 105 days.
- ‘Red Warty Thing’ (C. maxima) – 10-20 pound fruit, reddish-orange skin, bumpy warty appearance, non-stringy fine-grained flesh, maturity: 110 days.
- ‘Flat White Boer’ (C. maxima) – 15-17 pound fruit, creamy-white skin, stackable shape, full and aromatic flavor, maturity: 115 days.
- ‘Duchess’ (C. pepo) – 19-21 pound fruit, classic-orange skin, double-ribbed appearance, mild flavor, resistant to powdery mildew, maturity: 100 days.
Best Places To Buy Heirloom Pumpkin Seeds
Heirloom Pumpkin Seed Planting & Germination
- Seed starter mix
- 2-3 inch organic peat plant pots
- Nail file
- Heat pad
- Fluorescent grow light
1. File Down Seed Edges & Soak for 3-6 Hours
Starting in mid-late April, gently file down the seed edges with a clean nail file – this helps moisture reach the seeds and aids in damage-free seedling emergence.
Soak the seeds in warm water for 3-6 hours. Perform Step 2 while they soak. Drain the seeds, and set aside.
2. Prepare Organic Pots With Seed Starter Mix & Plant Seeds
Fill small peat pots with seed starter mix – it’s important to use biodegradable peat pots as cucurbit roots don’t respond well to transplanting stress.
These peat pots will break down in the soil after planting, so there is little disturbance to the seedlings when planting.
Plant 3-4 seeds per pot, placing them 1-2 inches deep in the mix with the pointed end facing downwards.
3. Water the Mix Well & Provide Warmth
Water the soil mix in the pots until moist, and place the pots on a heat pad to germinate, providing a temperature range of 75-95°F (24-35°C).
The seeds won’t require light at this stage. Anticipate seedling growth in 4-10 days.
4. Thin Seedlings Down to 1 Per Pot & Place Under Light Source
Once seedlings emerge, cut back all but the strongest-looking shoot in each pot at soil level with clean scissors.
Place the pots near a sunny window or 6-8 inches beneath fluorescent grow lights until the seedlings measure 2-3 inches.
5. Harden Off Seedlings a Week Before the Last Frost Date
To acclimatize your seedlings to the cold, harden them off 7-10 days before the last local frost date by placing the pots in an unheated greenhouse or clustered in a large open tub/crate placed outside for an hour each day.
Increase the number of hours the pots stay in their cold setting as the week goes by.
6. Prepare a Well-Draining Soil Bed & Plant Seedlings
Choose a full-sun planting site, and prepare a fertile, well-draining soil bed by mixing organic compost into your native soil. Ensure the soil temperature is at least 65°F.
Next, make a hole large enough to plant each seedling up to the top of its organic pot.
Plant each seedling and backfill around – spacing each seedling according to its variety recommendations.
Water well to maintain a moist soil bed, and provide supplemental watering during dry periods using drip irrigation.
Germinating Heirloom Pumpkin Seeds for Edible Sprouts
- Using hulled/naked pumpkin seeds, place 2/3 cup of seeds in a sprouting jar, and soak them in cool water for 2 hours.
- Drain and rinse the seeds well before returning them to the jar. Cover the jar with a cheesecloth or mesh lid, and place the jar upside down for 8-12 hours in a low-light location at room temp.
- Rinse and drain the seeds twice daily for 3 days. Store the jar on its side in between. Sprouts should emerge from the seeds within 3 days.
- After sprouting, rinse the seeds once more, and lay them flat on a tray/pan to dry. Once dry, store them in an airtight container in the refrigerator where they’ll stay fresh for up to 3 days.
5 Tips for Growing Heirloom Pumpkins From Seed
- Place a small fan near your seed pots during/after germination to improve air circulation.
- If you don’t have a heat pad, generate a warm microclimate by placing a humidity dome over each pot. This can be a glass cloche or a plastic bottle cut to size.
- Only water seedlings when the soil becomes dry. Overly wet soil can promote disease, and perpetually dry soil stunts development.
- Add a little liquid fertilizer once the seedlings emerge to speed up growth. Choose a 1-2-1 NPK ratio fertilizer and dilute it to ½ strength.
- Keep a record of germination times, temperatures used, any issues, etc. for future reference.
Growing & Caring for Heirloom Pumpkins
You’ve nurtured the seedlings indoors and have finally planted them outside – but the work doesn’t end here!
To coax the plants into fully-fledged pumpkin fruit, you’ll need to provide their ideal garden environment until they’re ready to harvest.
Heirloom pumpkins thrive in richly organic soil – this provides excellent drainage and plenty of nutrients.
Add plenty of manure, grass clippings, or compost to your soil before planting, and conduct a soil pH test (5.8-6.8 is the perfect range).
Also, add a 2-3 inch layer of mulch to keep things moist while preventing any weeds from germinating, taking care to keep an inch of space between the mulch and the pumpkin vines to prevent bugs and stem rot.
Pumpkins need maximum sun exposure during their growing period. A full-sun location in your garden essentially means a spot that gets at least 6 hours of daily direct sunlight throughout spring/summer.
Watering & Fertilizing
The vines require a gentle soaking of about an inch of water a week.
Take care to water at root level with either a hose or drip irrigation system as sprinklers risk splashing the leaves, causing potential disease.
Once the plants measure a foot tall, you can start applying a nitrogen-rich fertilizer, like this organic 7-6-9 plant food, once a week before moving on to a potassium-rich feed once the fruit appears.
Check the main stem or “handle” for dryness and a shriveled texture. The fruit should’ve also developed a rich, even color, and the skin will feel hard to the touch.
Cut the handles with heavy-duty pruning shears, leaving 3-4 inches of the stem, and harden the pumpkin outdoors for a week to ripen fully. After that, it’s yours to bake, carve, or use as festive décor!
Heirloom Pumpkin Common Questions:
What Does Heirloom Pumpkin Mean?
Heirloom pumpkins are grown from seeds that have been saved and passed down through the generations (typically over 50 years), allowing growers to reproduce the pumpkin variety in its original form.
What Brand of Pumpkin Seeds Are Best?
Burpee offers a wide selection of affordable, high-quality pumpkin seeds with a 1-year guarantee.
Turtletree Seed is another trusted brand among gardeners, selling pumpkin seeds that are non-GMO and prepared without the use of chemical agents.
How Long Do Heirloom Pumpkins Take To Grow?
Heirloom pumpkins take roughly 3 months to grow fully. As each heirloom variety differs, it’s important to check individual seed packets or manufacturers to determine maturity rates.
What Are the Benefits of Using Heirloom Pumpkin Seeds?
Heirloom pumpkin seeds provide superior fruit quality, flavor, and size compared to commercially grown pumpkin varieties.
Gardeners also favor heirloom pumpkins for the unique shapes and colors produced.