Seed starting with soil blocking from beginning to end.
We use the soil blocking method of seed starting. My experience has been that once equipped with a soil blocker tool, all you add each year are seeds and blocking mix. What drew my initial interest was that 40 blocked plants fit on a 5” x 7” tray and watering is self-contained, a perfect fit for starting seeds in a home. More seeds sprout because of the ideal growing environment. The healthy transplant produced using soil blocking outperforms other methods.
Caring for seedlings
Regardless of the method used to start the seeds, they all require basically the same growing conditions to sprout and grow into a healthy transplant.
- Water the seeds daily or as needed allowing the soil mix to become almost dry between watering.
- To get more seeds to sprout, use a seedling heat mat. Most seeds sprout at 70 to 85 degrees; while most homes are 70 degrees, the mass of soil you plant the seed in is 15-20 degrees cooler than the surrounding air temperature. So, 70-degree house equals 55 -degree soil. Cool soil is the leading cause of failure due to few or no seeds sprouting. The seedling heat mat has a built-in thermostat that keeps the trays 15-20 degrees warmer than the surrounding room temperature. When you use a heat mat, more seeds will sprout and more quickly. Once 50% of the seeds sprout, move from the heat mat to light. The mat can support 120 soil blocks at a time.
- Seedlings need 16 hours of light a day to grow into a strong plant. 16 hours of daylight are not available from natural light. When plants do not get the necessary light they begin to stretch and search for light which leads to tall leggy plants with faded foliage. Using a tabletop grow light with a timer, you can provide 16 hours of light. Our 4-6” transplants grown under lights would be over 18 inches or more without it—and not in a healthy way. The tabletop grow light uses a space 12” x 24” and can support up to 120 soil blocked plants at a time.
- Once sprouted, feed plants with liquid organic fertilizer weekly to encourage healthy growing. Use Seaweed/ Fish fertilizer according to directions in your watering once a week while growing indoors and continue once planted in the garden. In the garden, using a watering can to sprinkle the foliage as well as pouring on the soil. Sprinkling the foliage is called foliar feeding and adds fabulous disease and pest resistance to your plants.
Our carport full of seedlings hardening off.
- Moving the seedlings outdoors is called hardening off. This process gently acclimates your plants to sun, wind, cool temperatures, or heat before being planted out in the garden. We place our trays of blocks out under the covered porch for about a week before planting in the garden. This allows them to get early morning sun and wind to toughen them up.
- To prevent smashing plants, mulch before planting. Mulch the area to be planted by laying overlapping layers of newspaper topped with bark, pine straw or whatever organic mulch is available. We use the black biodegradable film Biotelo in our gardens. You can leave it uncovered as we do or use it in place of newspaper under mulch. Lay it out, cover the edges with soil and pop a hole in the Biotelo with your finger to plant your transplants. Follow the same for planting through mulch with newspaper under it. Both newspaper and Biotelo break down and can be incorporated into the soil safely. Water in well and give 1 inch of water a week if rain fall doesn’t provide.
- Cover with a floating row cover once planted in the garden for about 14 days. This adds a level of protection that protects your plants from the elements and marauding wildlife. Row cover allows air, water and light to pass through, but prevents drying winds, bright sun and rabbits, squirrels and deer from damaging your transplants. Row cover eliminates the anxiety of what might happen to plants once planted.
When you start from seed—you never know what you may grow into!
Once you master seed starting, anything is possible in your garden. You can grow all those plants not available down at the garden center and you will join the ranks of the proud seed starters!
Lisa Mason Ziegler founder of The Gardener’s Workshop and Flower Farming School Online.
Award-winning Author of Vegetables Love Flowers, and Cool Flowers. Watch Lisa’s Story and view her blog Field & Garden. Connect with Lisa on Facebook and Instagram!