Organic Pumpkin Seeds::Organic Specialty Pumpkins::Organic Kakai Hulless Pumpkin
Organic Pumpkins - Growing and Seed Saving InfoPrintable version of this page
| Types of Pumpkins |
| Pumpkins (Cucurbita spp.)are long-season tender annuals in the Cucurbitiacea family, which includes cucumbers, summer squash and winter squash, melons and gourds. |
- Pie pumpkins are intended for eating and have been selected for flavor, texture and density of flesh.
- Specialty pumpkins have superior eating qualities in addition to their unique physical attributes. Jack O’
- Lantern pumpkins are strictly decorative, selected for shape, size, handle quality, uniformity, and durability.
| Soil and Nutrient Requirements |
| Pumpkins grow best in fertile, well-drained soil, with pH between 5.8-6.8. Sidedressing is recommended one week after blossoming and again 3 weeks later, especially if there are signs of deficiency. Nitrogen deficiencies cause yellowing, and bronze leaves are a sign of potassium deficiency. |
| Position |
| Full sun |
| Seeding Depth |
| 1/2-1” |
| Seeding Rate |
| 2-3 seeds/18-36”, thin to one plant per spacing |
| Plant Spacing |
| For bush varieties 18”, for vining 24-36”. Tighter plant spacing will result in yields of smaller, but more numerous, fruit. |
| Row Spacing |
| Row spacing: for bush/semi-bush and short vine types 6’, for vigorous vining types use 9-12’. |
| When to Sow |
| Days to maturity are from direct seeding, subtract 2 weeks if transplanting. Seeds can be direct seeded after danger of frost has passed and soil temperature has reached 70°F. Start transplants indoors 3-4 weeks before last risk of frost. Optimal soil temperature for germination is 85-95°F. |
| Other Considerations |
| Black plastic mulch and floating row cover can also be used to increase soil and air temperature, as well as ward off cucumber beetles which eat young seedlings and spread disease. Remove row cover when flowers open to allow for insect pollination. |
| Frost Tolerant |
| The pumpkins themselves can withstand a few very light frosts in fall, but should be harvested before hard frost to avoid damage to the skin. |
| Drought Tolerant |
| No |
| Heat Tolerant |
| Yes |
| Seed Specs |
| C. pepo- 140-250 seeds/oz (175 avg), 2,300-4,000 seeds/lb (2,800 avg); C. moschata- 280-375 seeds/oz (310 avg), 4,500-6,000 seeds/lb (5,000 avg); C. maxima- 135-200 seeds/oz (155 avg), 2,200-3,200 seeds/lb (2,500 avg). M=1,000 |
| Seeding Rate |
| Bush/Semi-bush- 10,000-15,000 seeds/acre, (C. pepo ~ 3.5-5.3 lbs., C. moschata ~ 2-3 lbs., C. maxima ~ 4-6 lbs.) using 2-3 seeds/18” on 6’ centers. Vining- 3,500-5,000 seeds/acre (C. pepo ~ 1.25-1.8 lbs., C. moschata ~ .7-1.0 lb., C. maxima ~ 1.4-2.0 lbs.), using 2-3 seeds/36” on 6’ centers. |
| Harvest |
| Harvest by cutting stem near vine or at least 2-3” from fruit. Too many days of sun on fruits after maturity will bleach handles and cause sun scald on the fruit. |
| Storage |
| A short or broken stem can lead to rot. Cure after harvest by keeping in a warm, dry location for a few days then store at 50-55°F with 55-75% relative humidity and good air circulation. Delicata and acorn squash do not need curing, but will not store as long as other varieties. |
| Pest Info |
- Striped cucumber beetles cause feeding damage to the leaves, and often transmit bacterial wilt. Larvae feed on the plant roots. Row covers can provide effective protection, but must be removed during flowering to allow pollination. Practice crop rotation and good sanitation to eliminate overwintering habitat. Frequent application of kaolin clay and/or pyrethrum have shown some effective control.
- Squash vine borer will cause plants to look wilted even when moisture is plentiful. Slice open stem and remove and destroy.
- Squash bugs can be controlled by handpicking. Bury or compost plant residues at the end of the season.
| Disease Info |
- Powdery mildew, caused primarily by the fungus Sphaerotheca fuliginea, results in reductions in overall yields and quality of harvested fruit. Powdery mildew does not overwinter in the northeast (spores cannot withstand cold and cannot persist in the absence of host tissue) but blows north every year from southern states where crops are planted earlier. Powdery mildew is difficult to control with fungicide applications, even conventional ones, because the fungi multiply rapidly and attach to the undersides of leaves where they are difficult to reach with sprays. Many newer pumpkin varieties have been developed with tolerance to powdery mildew (PMT). Plants can still become infected but the symptoms are usually much less severe.
- Pumpkins are also subject to several fruit rots, of which the most common is probably black rot, caused by the same fungus that causes gummy stem blight (Didymella bryoniae). Recent research indicates that control measures for powdery mildew, including the use of PMT varieties, is also effective against black rot. In the case of black rot, the pathogen can be seed-borne and survive in crop residues.
- Scab – Avoid wetting foliage and give plants plenty of space for circulation.
| Seed Saving Instructions |
| Insect pollinated. Take caution unless you are hand pollinating, as many pumpkin varieties are the same species as many summer squash and winter squashes. Different varieties of the same species need to be isolated by 1/4 mile to prevent cross-pollination. Barriers such as tree lines, woods or buildings existing between the fields can reduce this distance. Treat pumpkins the same as usually done for winter storage. After all squashes have reached this stage, harvest and let them sit for a period of after-ripening for 3-6 weeks or up to several months. Remove the seeds, rinse in water and dry. Use of a 1/2" and 1/4" screen can help with cleaning. Squash seeds remain viable for 6 years under cool and dry storage conditions. |