When to Plant Indoors Think backwards when starting seeds. Our average last frost date is between the 15th and the 20th of May. Look at the number of weeks listed on the seed package on how many days it takes to emerge. Then count backwards from the average last frost date. Most seeds should be started six to eight weeks before that date. Some seeds can be started a few weeks before, while others may need 12 to 14 weeks. If you start seeds too early, they will become leggy and to weak to transplant outside. It is really important to read the seed packet.
Supplies You will need to start with quality seed and seed starting mix. Most seed starting mixes are sterile and blended to be light and porous so fragile seedlings get both the moisture and the oxygen they need to thrive. If it is not sterilized, you can do this by baking the mix in the oven. This is not pleasant as it smells awful. Please research this before trying it or contact me for a recipe. Containers for seed starting can be commercial seed starting pots or recycled household items like milk and egg cartons or yogurt cups. Be sure to punch holes for drainage.
Scoring Hard shelled seeds need to be scored also called scarification. This is lightly nicking or scratching the coat to allow water to enter the seed to make is easier to germinate. Lightly rub the seed with sandpaper or a file. Some seeds only need to be soaked overnight. This tricks the seed into thinking it was planted longer and helps it germinate faster.
Cold Treatment There are seeds that need a cold treatment. This is called stratification. One way to stratify seeds is to soak the seeds for 24 hours and combine them with a mix of moist coir or peat and sand in a plastic bag. Place the mixture in the refrigerator for 4 to 12 weeks. Read the seed packets carefully, it should tell you this information.
Plant containers to the top with moist soil mix and firm. Scatter a few seeds evenly over the surface. If the seed needs to be covered (according to the seed packet) do so, gently press seeds into the mix and scatter a little mix over the seeds. Lightly press the mix down. Be sure to label your pots. Keep the soil moist during germination, as well as after. Mist the seedlings. Cover with plastic wrap or a humidity dome until they germinate. Place containers in a warm spot, like the top of the refrigerator. A seedling heat mat is ideal. After germination, remove any covering. Note: Slightly cooler temperatures will slow down growth and result in stockier plants.
Lighting is critical as soon as seedlings begin to emerge. Use grow lights or fluorescent shop lights suspended from chains a few inches above them. Pull up the chain as the plants grow. If you are growing them in a sunny windowsill make sure you rotate the plants.
Damping off This is one of most depressing things that can happen when starting seeds. Your seedlings are coming up nicely then next thing you know they're all flopped over. What happened? Damping-off. It is a fungal disease that can kill seedlings overnight. The fungus rots the stems at the soil surface, causing the seedlings to fall over and die. The reasons could be any one these: to crowded, the soil could be to wet,cold, heavy or you may have bad seeds. Natural preventative solutions that may help are: Don’t plant to close together. Snip off extra seedlings early, being over crowned can lead to damping off. Put a small fan near by to keep air moving. Warm the soil with bottom heat to help seeds germinate. Make Chamomile tea to mist or water in. Chamomile is a concentrated source of calcium, potash and sulfur. The sulfur is a fungus fighter. This can also be used as a seed soak before planting. Cinnamon acts as a natural fungicide. Sprinkle powdered cinnamon on the soil. Don't worry if you get cinnamon on your plants as it will not hurt the seedlings. Worm casting tea can also be used as a preventative.
Hardening Off means you need to acclimate seedlings outside with 2-3 hours of filtered sun, gradually lengthening the time and giving them more sun exposure. Bring them inside or cover them during cold nights. In a couple of weeks your seedlings will be strong enough and ready for planting in the garden.