1. Do some planning, label everything, and keep notes on the process. Remember: Small seed packets become numerous large plants!
2. Determine the time to start your chosen seeds. Do not start them too early. You will need to look up the average last date of spring frosts and average last date of fall frosts for your area. For Saskatoon the dates are May 21 and September 15.
3. Using your frost dates refer to online seeding charts to determine the time to start your seed varieties.
4. Seeds can be started in new cell packs or recycled deli/yoghurt containers. It is extremely important to wash these containers (even the new ones)in soap and water. Rinse them in a light bleach/water rinse. Make sure each container has drainage and a drip tray.
5. Choose a quality brand seed-starting soil mix. Some brands contain a light fertilizer as well. Do not use garden soil as you are more likely to develop fungal problems.
6. If possible, invest in a heat mat or two and LED grow lights with a timer. New seedlings need 16-18 hours of light per day. They also need a period of rest at night. Natural window light creates leggy, weak plants.
7. Plant your seeds at the recommended depth and cover with clear tray domes or plastic. Check daily for water germination and water requirements. DO NOT OVERWATER! Once seedlings emerge, remove covers and keep them at a room temperature between 15-21 degrees C. As the seedlings grow, keep the grow lights 7.5 to 10 cm. from the top of the plants.
8. If your seed starting soil does not contain fertilizer, begin a very light all- purpose fertilizer application when seedlings develop their first true leaves. The first pair of ‘leaves’ you see are actually the seed coat orcotyledons that store food and feed the plant until the true leaf sets form and start to photosynthesize. Young seedlings only need a pinch of fertilizer weekly in a small watering can.
9. If you have too many seedlings per cell pack trim extra stems back at the soil line with scissors. At some point you may also need to move your seedlings into larger 3-4 inch diameter pots. Again use a good top quality soil and a container that has drainage.
10. Last, but certainly not least, harden off seedlings before planting outside. Hardening off is increasing the time outdoors per day for about 5 days. Avoid placing the plants in full sun and windy locations during this hardening off period. Start at about 2 hours a day.
A word about damping off. Damping off is a fungal disease that kills seedlings. These fungi are most at home in cool, wet soil. As I mentioned, a heat mat is a great investment to ensure soil warmth during germination. Keep your seed starting environment as clean as possible. Use warm water to irrigate your plants. Keep a small fan in the same room as your seedlings. Good air circulation is key.