Seed Storage Guide for Pepper Growers

Preserve Viability, Maximize Longevity, and Protect Your Collection

1. Why Proper Seed Storage Matters

Capsicum seeds can remain viable for several years—but only if stored under the right conditions. Improper storage leads to reduced germination, loss of genetic material, and weakened seedlings. This guide outlines optimal practices for home, research, and long-term seed storage.

2. Basic Principles of Seed Longevity

– Dry and cold are the two most important factors.
– Every 1% decrease in seed moisture and every 10°F (5.5°C) drop in temperature roughly doubles shelf life.
– Seeds should be fully mature, cleaned, and dried before storage.

3. Seed Drying

– Air dry seeds on a screen or paper towel in a dark, ventilated space for 7–10 days.
– Use silica gel or desiccant pouches for precision drying (target 6–8% moisture).
– Avoid oven or sunlight drying—this can kill seeds.
– For long-term storage, verify dryness with a hygrometer or use a desiccator box.

4. Packaging Options

– Short-Term (1–2 years): Paper envelopes, coin packets, labeled zip bags.
– Mid-Term (3–5 years): Poly zip bags with silica in airtight container.
– Long-Term (5–15+ years): Vacuum-sealed Mylar bags or sealed glass vials in cold storage.
– Label everything clearly: species, variety, harvest year, and any traits.

5. Labeling Best Practices

– Use acid-free paper or archival labels.
– Avoid only writing on plastic with marker—it fades over time.
– Include: binomial name (C. annuum), cultivar (‘Aji Dulce’), year, grower name, and notes if needed.

6. Storage Conditions

– Temperature:
  – Room temp (20–22°C / 68–72°F) = viable for 2–3 years.
  – Refrigerator (4–8°C / 39–46°F) = viable for 5–8 years.
  – Freezer (-18°C / 0°F) = viable for 10–15+ years (must be fully dry first).
– Humidity:
  – Below 50% RH for short-term
  – 15–25% RH for long-term
– Avoid frequent temp changes or opening storage units.

7. Seed Viability and Germination Testing

– Test every 1–2 years:
  – Place 10–20 seeds on a moist paper towel inside a plastic bag.
  – Keep warm (26–30°C / 79–86°F).
  – Count germinated seeds after 7–14 days.
– Record results and decide if seed regeneration is needed.

8. Backup and Duplication Strategies

– Never store your only copy.
– Keep duplicate seed sets in another location (family, friend, fireproof box).
– Rotate your stock by growing out and saving fresh seed every 3–5 years.

9. Special Considerations for Wild and Rare Species

– Some wild Capsicum species lose viability faster or need stratification.
– Label subspecies carefully.
– Store separately from commercial hybrids to avoid cross-contamination.

10. Summary

Dry, cold, and stable environments extend seed life. Label thoroughly, test periodically, and back up important lines. Proper storage protects your investment—and helps preserve Capsicum biodiversity for future growers.