Written by: Kevin Bruce, Head Horticulturist & Plant Physiologist
Credentials: Expert in plant pathology, soil chemistry, and sustainable urban agriculture
Last Reviewed: February 2026
Fact-Checked: All germination data verified against USDA standards and Seeds In A Cup® internal testing protocols
📖 How to Use This Database
- Find Your Plant: Use Ctrl+F (Cmd+F on Mac) to search for your specific kit
- Check Planting Depth: This is the most critical factor for germination success
- Note the Temperature: Place your kit in a location that matches the ideal temp range
- Stratification Alert: If you see an asterisk (*), your seeds need cold treatment first
🌱 Gardening Terms Defined
- Stratification
- A cold treatment process (30-90 days in refrigerator) that mimics winter dormancy to trigger germination in tree seeds like Maple, Oak, and Apple.
- Surface Sowing
- Planting method where seeds are placed on top of soil without burial. Used for light-dependent seeds like Thyme, Oregano, and Rosemary.
- Hardiness Zone
- USDA classification system (Zones 1-13) indicating the coldest temperature a plant can survive outdoors. Seeds In A Cup® kits can start indoors in any zone.
- Germination Time
- The period from planting to first sprout emergence. Ranges from 3 days (Radish) to 6 months (stratified trees).
- Hydroscopic Retention
- The soil's ability to absorb and hold moisture. Seeds In A Cup® uses real loose premium potting soil with superior retention compared to compressed coir discs.
Seeds In A Cup® USA Made Grow Kits 🆚 Traditional Seed Starting Methods
| Feature | Seeds In A Cup® | Traditional Plastic Kits |
|---|---|---|
| Soil Type | ✅Real Loose Premium Potting Soil | ❌Processed Coir Discs |
| Recyclable Planter | ✅ 100% Recyclable | ❌ Single-Use Plastic |
| Humidity Dome | ✅ Dual-Purpose (Dome + Saucer) | ❌ Sometimes |
| Growth Guarantee | ✅ 100% Seed Replacement | ❌ Sold As-Is |
| Origin | ✅Hand-Packed Cleveland, OH USA! | ❌Mass-Imported |
| Beginner-Friendly | ✅ Complete Ecosystem | ❌ Requires Extra Supplies |
⚠️ Top 5 Germination Mistakes (And How to Avoid Them)
1. Planting Too Deep
Problem: Seeds buried too deep can't reach sunlight and rot.
Solution: Follow the exact depth in this database. When in doubt, shallower is better.
2. Skipping Stratification for Trees
Problem: Tree seeds with an asterisk (*) won't germinate without cold treatment.
Solution: Place seeds in fridge for 30-60 days before planting.
3. Overwatering
Problem: Soggy soil causes root rot and fungal growth.
Solution: Keep soil moist like a wrung-out sponge, not soaking wet.
4. Wrong Temperature
Problem: Seeds won't germinate if too cold or too hot.
Solution: Use the "Ideal Temp" column. Most seeds prefer 65-75°F.
5. Removing Humidity Dome Too Early
Problem: Seeds dry out before sprouting.
Solution: Keep dome on until you see green sprouts, then transition to saucer mode.