Create an environment for seedling success
Feb 22, 2024 02:54PM ● By Bryan ReedPlanting from seed is gratifying and cost effective. It allows seeds to explore new environments while allowing us to introduce desired species into our gardens.
Professional growers can select crop varieties that are unique to the market, easy to harvest and easy to store. Similarly, home growers can experiment with new varieties or preserve heirloom seeds for future plantings. Most vegetable crops can naturalize over four to seven generations, making it possible for heirloom seeds to acclimate to specific growing conditions such as our clay soils, mineral-rich water and cool nights.
Starting seeds yourself is easy to do providing you ensure the five necessary conditions for germination.
GOOD SEEDS
If you buy seeds new, you’ll know you have a living seed that will germinate for you. However, if you’re using saved seeds or seeds from old packets from the bottom of the garden supply box, then a germination test will be beneficial. To perform this test, place 10-20 seeds in a paper towel (be sure to write the variety on the towel) and roll it up. Mist the towel until it’s wet, then place it in a jar or canister with the lid cracked open to allow airflow. Keep the towel in a warm location and check it after the number of days required for the seed to sprout. For a 7-10 day germination period, you can extend the test to Day 12 to ensure all viable seeds have sprouted. Count the number of sprouts divided by the number of seeds started to calculate the germination percentage. While 80-100% germination is ideal, even a 50% germination rate indicates the need to plant two seeds per hole.
OXYGEN
Choose a quality germination soil that allows for adequate airflow. And remember: Don’t compact the soil when planting the seed, as this can hinder airflow and affect germination.
MOISTURE
Seeds need 50-75% moisture to germinate. It’s important to avoid overwatering, but don’t let them completely dry out either. Instead, aim for consistent moisture levels by watering or misting daily, or even multiple times a day if necessary.
Indoors, a humidity dome can help maintain soil moisture. Outdoors, we can build a mini hoop structure out of bent electrical conduit, 9 wire or even willow branches covered with plastic to create a mini greenhouse.
For small seeds planted outdoors, flattened cardboard boxes can be used to retain moisture. After planting the seeds, water the soil, then dampen the cardboard and place it over the seeds, securing it with rocks or bricks. The corrugated cardboard acts as a sponge, releasing moisture into the soil while shielding the seeds from sun and wind. Ensure the cardboard remains moist, and once 50% of the seeds have germinated, remove it to allow the remaining seeds to emerge within a day or two.
TEMPERATURE
Seeds require specific temperatures to germinate successfully. Cold-season crops typically germinate best between 45-75°F, while warm-season crops prefer temperatures of 60-90°F.
Indoors, using a heat mat under the seedling tray can provide warmth. These mats often come with a thermostat, allowing you to set the temperature to the sweet spot for your seeds. For most cool-season crops, a temperature around 68°F is optimal, while warm-season crops thrive at around 80°F.
Outdoors, it’s important to check the soil temperature before planting. To raise soil temperature, you can lay down a plastic square in the garden and secure it around the edges to retain heat. Within about a week, the soil temperature should become suitable for planting your crops.
Creating a mini greenhouse using six straw bales and a salvaged sliding glass door is a great way to warm the soil and protect seedlings from overnight cold. Once temperatures rise, remove the straw bales and relocate them to another area for planting warm-season crops.
SOIL
Seeds require good seed-to-soil contact to germinate. Chunky, gravel sandy soil types have large air pockets that inhibit the seeds from staying moist.
When seeding indoors, it’s beneficial to use coconut coir, peat moss, small perlite or a commercial germination mix that contains fine materials. These materials hold water well, ensuring the seed remains in contact with moist media for optimal germination.
Outdoors, we can create a suitable environment for germination by digging a small 1-inch trench and lining it with coconut coir or peat moss. This helps maintain moisture around the seeds for better germination. Clay is a much finer soil particle than silt or sand. It can be lightly broken up on the surface to create finer particles in the top ½ to ¾ inch where seeds are planted.
Mark Your Calendar!
Ideal Seed Planting Days in March
For those following the biodynamic calendar, the ideal days for planting seeds in March are the 1st and 2nd along with the 15th-29th. Rhythm OfNature.net provides calendars for gardening tasks, home chores, health practices and beauty regimes.
FREE WORKSHOP
Don't miss Bryan's Seed Saving Workshop at Mesa County Libraries' Central Branch, 443 N. 6th St., on March 27 at 6 p.m. to learn more about saving seeds.