Best Practices for Early Season Seedling Propagation
I love this time of year. Outside the snow is still piling up, but inside we’re sowing seeds. It feels like a giddy secret—the smell of soil, the germinating seeds and the unfurling of true leaves, while outside the plow is rumbling down the road and every non-farmer is wondering how long winter will last.
Okay, every farmer is wondering how long winter will last, too, but at least we’ve got a jump start of the feeling of spring.
Early season seedling propagation is more than just a way to beat the winter cold, of course. It’s a way to jump start the harvest season, and to be ready to hit the ground growing once the snows melt and the fields dry.
As you start your seedlings, keep these best practices in mind.
Factors Affecting Germination
- Seed condition
- Think Goldilocks when it comes to water: not too much, not too little. Too much water can cause the seed to rot. With too little water, it won’t sprout at all. Or worse, if the seed begins to germinate and then dries out, it will die. During the germination phase, it’s important to have consistent moisture. To avoid overwatering and drying out, cover the moist soil with a plastic dome, wet paper towel, or tray. Check on the flats a few times a day and mist with a misting nozzle or spray bottle when needed.
- Seeds need oxygen to germinate. This is one reason you want to avoid over-watering, since waterlogged soil doesn’t allow for proper airflow.
- Most crops germinate best in soil that is 75º-90º F. Consistent and appropriate soil temperatures will ensure quick germination. Check the growing recommendations for each crop to find out the ideal temperature, and use heat mats to efficiently warm the soil without having to heat the air as much.
- Most vegetable seeds don’t need light to germinate. Once the seeds have germinated, remove any covering (paper towels, plastic dome, or tray) and immediately set under light. It’s important that sprouts get immediate access to light. If they don’t, they’ll get leggy as they stretch and search for it.
Best Practices for Starting Seeds in Your House
Winter in Vermont is cold! Often, it’s more economical to start seeds inside a house than to turn up the heat in the greenhouse and maintain 65º+F. Starting inside gives you a two week jump on seed starting without having to heat the greenhouse.
Start by setting up a propagation station. You can purchase a grow light stand or make your own. If you’re the DIY type, you can easily make a grow light stand with metal shelving and shop light fixtures with fluorescent or LED bulbs from the hardware store.
Grow lights are worth the time and small investment to set up. Don’t rely on the windowsill for starting seeds inside, as your plants will become leggy reaching for the sun. When growing under lights, keep the bulbs close to the plant: 1”-2” away is ideal.
If you like to keep your house on the cooler side, invest in some heat mats to warm the soil. This will help keep a steady soil temperature, which in turn promotes quick germination. Once the plants have germinated, you can turn the heat mats off. While heat can help germination, after the roots are established and your seed is a seedling, too much heat can cause damage and make the plants wilt.
Use warm water when watering your seedlings. This helps maintain the warm soil temperature ideal for germination and plant growth. And remember not to overwater flats in the germination stage! A spray bottle or a Fogg-it nozzle hose attachment provides gentle moisture that’s ideal for newly seeded trays.
Finally, set up a fan for air circulation. Proper air circulation improves plant growth by decreasing stagnant moisture and potential for damping off, and providing fresh air for the plant to photosynthesize.
And now it’s time to get growing!
Check out this planting chart to plan out your seed starting calendar. And tell us what crops you’re starting this year in the comments below.
Kate Spring is an organic farmer, mother, and chief inspiration officer at Good Heart Farmstead in Worcester, Vermont.