Seed Starting: A Practical Guide

I was a biodynamic herb grower for over a decade and experimented with seeds starting in my greenhouse every year. In the fall, I always felt exhausted and craved some rest; I could never imagine farming for one more full season in October. But in April, I longed to dig my hand in the dirt. The vibe in the greenhouse in spring was filled with hope and anticipation. A couple of factors play into a successful seeding and germination season: Timing: When you decide when to start your seeds, you want to factor in the weather where you live and the type of seeds you are planning to start. Seeding too early or too late can ruin the entire season. In New Hampshire, the last day of frost is somewhere at the end of May; therefore, I can't transplant my seeds before then. The saying "as above, so below" applies to seedlings, too. If the aerial part of the plant is developed with many leaves, so are the roots. If you have a well-developed plant in a small cube on a tray, the plant will suffer if not transplanted. Seeding too early means your plant will be ready to be transplanted before your garden can offer optimal growth conditions. Perennial seeds generally take longer to germinate. I started all my perennial herbs from seeds in early April; it takes a lot of patience and trust before they start to germinate, so keep on checking on them and watering them even after weeks pass. Annual herbs like Tulsi and calendula are easy and fast to germinate. I started seeding them only in May. Check your seed packages and the average germination time to plan accordingly. Using the Biodynamic Planting Calendar: As a biodynamic farmer, I worked with the biodynamic calendar. The biodynamic calendar follows the moon's movement in front of the 12 zodiac constellations as a guideline for timing tasks in the farm. The 12 zodiac constellations were associated with the four elements: earth, water, air and fire. Each element is related to a part of the plant. Earth/Roots: When the moon is in Taurus, Virgo and Capricorn, it is a good time to seed and harvest roots such as astragalus and licorice. Water/Leaves: When the moon is in Cancer, Scorpio and Pisces, it is a good time to seed and harvest leaf crops such as Tulsi, sage or thyme. Air/Flower: When the moon is in Gemini, Libra and Aquarius, it is a good time to seed and harvest flowers such as calendula and chamomile (flower harvesting is a daily chore that can't be squeezed into the biodynamic calendar) Fire/Fruits: When the moon is in Aries, Leo and Sagittarius, it is a good time to seed and harvest fruits like cayenne pepper. Watering: The greenhouse environment is typically hot and dry. We water the plants daily, sometimes twice. The best way to know how much you need to water your plants is by touching the soil. Plants don't like their "feet" to stand in water, but they don't like dry soil either. When watering your plants, you want a gentle stream of water imitating the rain or your shower head. A strong stream of water can break the tender stems of seedlings. Direct Sow, Block Trays or Flat Trays: The decision of where to start your seeds depends on what the plant requires to thrive. Chamomile likes to be sowed late in the fall directly in the ground. It requires cold treatment for better germination. Calendula, astragalus and licorice seeds are relatively large. They can be easily started in blocks and will thrive there. Tiny seeds like thyme, sage and hyssop are hard to start in a block. Fill a flat tray with potting soil, make a long indent in the soil with your finger, spread the seeds and cover lightly. If you start your seeds in a flat tray, you will most likely need to thin them. Soil: We were lucky to mix our potting soil with compost from our goats and chicken. Now that I don't have farm animals, I buy organic seed-starting soil. Commercial soil mix containing peat moss, vermiculite and perlite works well. A soil mix reduces the risk of soil-borne diseases and pests, ensuring a healthier start for seedlings. It's also light and fluffy, allowing young roots to establish easily. Avoid starting seeds in the soil from your garden, as this soil is heavy and littered with pests and weed seeds. Sunlight & Temperature: Seeds require 12 hours of sunlight (germination lamps work too) and temperatures above 40 degrees Fahrenheit. You can start your seedlings in your home next to a south-facing window, in a cold frame or in a greenhouse. Special Considerations and Terms: Cold stratification: cold treatment is necessary for some perennials. It mimics winter by exposing seeds to cold for two to three weeks. Arnica and echinacea benefit from cold exposure. I mixed the seeds with potting soil and placed it in the refrigerator for a few weeks before spreading the mix in a seedling tray in the greenhouse. Scarification: tough seeds need to be nicked or scratched because their outer coat is too thick. Astragalus and licorice benefit from scarification. Licorice is especially hard to germinate without being "sanded" before sowing. Soaking: some seeds, such as basil and parsley, need to be soaked in water before sowing. Special Growing Gadgets: You can optimize your seed germination rates using grow lights and heating mats. Grow Lights: Full-spectrum grow lights provide red and blue light and are ideal for seedling development. These wavelengths support healthy growth. Standard LEDs or fluorescent lights may not provide the same benefits, so investing in proper grow lights is worth considering. Heat Mats: Using heat mats with a thermostat ensures consistent soil temperatures, especially for heat-loving crops like tomatoes or basil. A thermostat allows you to fine-tune the heat mat to the optimal range for each type of seed. I believe everybody has a green thumb, and you learn by doing. Start small and grow your garden as you improve. Have fun!