Cucurbits: Squash, Cucumbers & Melons
Master seed saving from squash, cucumbers, and melons - insect-pollinated crops that require isolation.
Overview
Cucurbits are insect-pollinated and will cross readily within the same species. Understanding species groups is essential: summer squash crosses with zucchini and some pumpkins, but NOT with butternut squash. The good news is seed extraction is simple - just scoop and rinse!
Crops Covered:
insect-pollinated
wet processing
2-3 weeks
Squash: 4-6 years
Understanding Pollination
Cucurbits have separate male and female flowers and rely on bees for pollination. They cross freely within species.
Isolation Distance
1/4 to 1/2 mile for purity (or hand-pollinate)
Key Tips:
- Learn the 4 squash species to understand crossing patterns
- C. pepo: zucchini, summer squash, acorn, delicata, some pumpkins
- C. maxima: butternut, buttercup, hubbard, banana squash
- C. moschata: butternut, cheese pumpkins
- Different species won't cross - grow one of each type
- Hand-pollinate and tape flowers closed for guaranteed purity
Step-by-Step Guide
Seeds must mature on the vine much longer than eating stage.
- Summer squash: Let grow huge and develop hard skin
- Winter squash: Leave until first frost or stem dries
- Cucumbers: Leave until large, yellow, and soft
- Melons: Leave well past eating ripeness
- Watermelons: Wait 3 weeks past normal harvest
Cut open the mature fruit and remove seeds.
- Cut fruit in half lengthwise
- Scoop seeds and surrounding pulp into a bowl
- For cucumbers/melons: seeds are in the center cavity
- For squash: seeds are attached to the inner wall
Separate seeds from pulp using water.
- Place seeds and pulp in bowl of water
- Work seeds free from pulp with your hands
- Good seeds sink, empty seeds and pulp float
- Pour off floating debris
- Strain and rinse until clean
Spread seeds to dry completely.
- Spread in single layer on screen or paper
- Place in warm, well-ventilated area
- Stir daily to prevent sticking
- Dry 2-3 weeks until seeds snap cleanly
- Large seeds take longer than small seeds
Harvest Timing
| Crop | Harvest Stage | Days After Flowering |
|---|---|---|
| Summer Squash/Zucchini | Very large, hard skin, can't dent with fingernail | 50-60 days |
| Winter Squash | Skin hard, stem dry and corky | 55-100 days |
| Cucumbers | Large, yellow, soft | 40-50 days |
| Melons | Very overripe, soft | 45-55 days |
| Watermelons | 3 weeks past eating ripeness | 50-60 days |
Processing: Wet Method
Cucurbit seeds are processed using water to separate seeds from the pulpy matrix.
- 1Scoop seeds and pulp into large bowl
- 2Add water and work seeds free with hands
- 3Let settle - good seeds sink
- 4Pour off floating material
- 5Repeat until water is clear
- 6Strain through colander
Drying & Storage
2-3 weeks
Warm (70-80°F), low humidity, good air circulation
Test for Dryness: Seeds should snap when bent. Large squash seeds take longer than cucumber seeds.
Paper envelopes, Glass jars, Breathable cloth bags
Cool, dark, dry. Squash and melon seeds store well for many years.
Squash: 4-6 years, Cucumbers: 5-10 years, Melons: 5-6 years
- Cucurbit seeds are large and easy to store
- Very long-lived when properly dried and stored
- Can successfully sprout 10+ year old cucumber seeds