Nightshades: Tomatoes, Peppers & Eggplant
Learn to save seeds from tomatoes, peppers, and eggplants using the fermentation method.
Overview
Nightshade family plants (tomatoes, peppers, eggplant) are among the easiest vegetables to save seeds from. They're mostly self-pollinating, meaning you can save seeds without worrying too much about cross-pollination. Tomatoes use the fermentation method, while peppers and eggplant seeds can be processed using either wet or dry methods.
Crops Covered:
self-pollinated
fermentation processing
7-14 days
Tomatoes: 4-6 years
Understanding Pollination
Nightshades are primarily self-pollinating. The flowers contain both male and female parts and pollinate themselves before opening fully.
Isolation Distance
10-50 feet for home gardens (commercial: 150+ feet)
Key Tips:
- Tomatoes rarely cross-pollinate - 10 feet apart is usually sufficient
- Peppers can cross more readily - use 50+ feet or bag flowers
- Hot and sweet peppers WILL cross - keep well separated
- For absolute purity, cover flowers with small bags before opening
Step-by-Step Guide
Choose fruits from your healthiest, most productive plants with the best flavor and characteristics.
- Select fully ripe or slightly overripe fruits
- Pick from disease-free, vigorous plants
- Choose fruits that represent the variety's best traits
- Mark plants early in the season before traits change
- Never save from the first or last fruits - middle of season is best
Cut the fruit and remove seeds along with the surrounding gel or pulp.
- For tomatoes: Cut in half and squeeze seeds with gel into a container
- For peppers: Cut open and scrape seeds into a bowl
- For eggplant: Slice overripe fruit and scrape seeds
- Include the gel (tomatoes) as it contains germination inhibitors to be removed
Ferment tomato seeds to remove the gel coating and kill seed-borne diseases.
- Add equal amount of water to seeds and gel
- Cover loosely (not airtight) and label
- Let sit at room temperature 2-4 days
- Stir once or twice daily
- Fermentation is complete when a layer of mold forms on top
- Don't over-ferment or seeds may sprout
Rinse thoroughly to remove all pulp and debris.
- Add more water and stir vigorously
- Viable seeds will sink; discard floating seeds and debris
- Pour off the top layer repeatedly
- Strain through a fine mesh sieve
- Rinse under running water until completely clean
Dry seeds completely before storing to prevent mold.
- Spread seeds in single layer on coffee filter, paper plate, or screen
- Label immediately with variety and date
- Dry in well-ventilated area away from direct sun
- Stir daily to prevent clumping
- Seeds are dry when they snap rather than bend (7-14 days)
Harvest Timing
| Crop | Harvest Stage | Days After Flowering |
|---|---|---|
| Tomatoes | Fully ripe to slightly overripe | 40-60 days |
| Peppers | Fully colored and mature (red stage for most) | 50-70 days |
| Eggplant | Overripe - past eating stage, skin dull and brownish | 50-60 days |
| Tomatillos | Husk brown and papery, fruit yellow | 60-70 days |
Processing: Fermentation Method
The fermentation process removes the germination-inhibiting gel from tomato seeds and kills many seed-borne diseases.
- 1Combine seeds and gel with equal part water in jar
- 2Cover loosely and place in warm location (70-80°F)
- 3Stir once or twice daily
- 4Process is complete when white mold forms (2-4 days)
- 5Add water, let seeds settle, pour off debris
- 6Repeat until water runs clear
Drying & Storage
7-14 days
Warm (70-80°F), low humidity, good air circulation, out of direct sunlight
Test for Dryness: Seeds should snap cleanly when bent, not bend or feel rubbery
Paper envelopes, Glass jars with silica gel, Sealed plastic containers
Cool (40-50°F ideal), dark, dry location. Refrigerator or freezer for long-term storage.
Tomatoes: 4-6 years, Peppers: 2-4 years, Eggplant: 4-6 years
- Always label with variety name and harvest date
- Include silica gel packets in sealed containers
- Bring to room temperature before opening to prevent condensation
- Test germination rate before planting old seeds