To germinate seeds in cups, you'll need to create a mini-greenhouse environment that provides consistent moisture and warmth. Here's a step-by-step guide:
1. Prepare the Cups:
- Take plastic or paper cups (any size will do, depending on the seed and desired seedling size).
- Crucially, perforate drainage holes at the bottom of each cup. This prevents waterlogging, which can kill seeds and seedlings.
2. Fill the Cups with Soil:
- Use a seed-starting mix or a well-draining potting soil. Regular garden soil is generally too dense and can hinder germination. Avoid soil with large chunks of organic matter.
- Fill the cups almost to the top, leaving about ½ inch of space.
3. Sow the Seeds:
- Follow the seed packet instructions for the correct planting depth and spacing. Generally, smaller seeds should be sown closer to the surface than larger seeds.
- For very small seeds, you can gently scatter them on the surface and then lightly press them into the soil.
- For larger seeds, make a small indentation with your finger or a pencil and place the seed inside.
4. Water Gently:
- Water the soil gently to moisten it thoroughly without disturbing the seeds. A spray bottle works well for this purpose.
- Avoid overwatering, which can lead to damping-off (a fungal disease that kills seedlings).
5. Create a Humid Environment:
- Cover the cups with plastic wrap, a plastic bag, or a clear plastic dome. This creates a mini-greenhouse that helps maintain humidity and warmth. You can also use a humidity dome specifically designed for seed starting.
- Make sure the plastic doesn't touch the soil or seedlings to prevent fungal growth. You might need to prop it up slightly.
- Alternatively, place the cups inside a larger plastic container with a lid.
6. Provide Warmth and Light:
- Place the cups in a warm location. Most seeds germinate best at temperatures between 65°F and 75°F (18°C and 24°C). A heat mat designed for seed starting can be beneficial, especially in cooler environments.
- Provide adequate light once seedlings emerge. A sunny windowsill can work, but supplemental grow lights are often necessary for strong, healthy seedlings. Rotate the cups regularly if using a windowsill to ensure even light exposure.
7. Monitor and Maintain:
- Check the cups daily to ensure the soil remains moist but not soggy. Water as needed.
- Once the seedlings emerge, remove the plastic cover to allow for better air circulation and prevent fungal diseases.
- Continue to provide adequate light, warmth, and moisture as the seedlings grow.
8. Transplant (if necessary):
- Once the seedlings have developed their first true leaves (the second set of leaves after the initial seed leaves), they can be transplanted into larger pots or directly into the garden, depending on the plant and the weather conditions.
By following these steps, you can successfully germinate seeds in cups and get a head start on your gardening season.
