The best way to ensure a completely organic vegetable crop is to always start from organic seeds purchased from a reputable source. Growing from seed will also allow you to get a jumpstart on the growing season by starting your vegetables indoors and moving healthy seedlings outside as soon as the weather permits. To be successful, here are 16 tips for growing organic vegetables from seed.
CHOOSE VEGETABLES KNOWN TO GROW WELL FROM SEED
While growing from seed can be a relatively easy process, some vegetables are surer bets than others. First time gardeners should try lettuce, radishes, beans, cucumber, tomatoes, cabbage, and Swiss chard.
Each vegetable has its own germination period as well as the best time to transplant seedlings to minimize shock. Learn the particularities of your vegetables and the frost dates for your area in advance so you can plan accordingly. For most vegetables, you can sow seeds indoors a few weeks prior to the last frost and transplant seedlings outside once the danger of frost has passed. If you are direct sowing seeds outside, you’ll likely want to get them into the ground as soon as soil temperatures will allow.
STARTING IN POTS
Pick the best container pots to start your seeds. While seedling trays and recycled yogurt containers work great, you may want to start with something a little bigger so you don’t have to transplant your seedlings too many times after germination. In general, a 3-6 inch container will allow most vegetables the room they need to grow before transplanting outdoors. Seeds sown in seedling trays will need to be transplanted into small containers so they can grow large and sturdy enough to survive transplanting outdoors.
Use the best potting soil or mix available to get your seeds germinated in the best conditions possible. Find out what kind of soil your vegetables prefer. In general, if you are using garden soil you will need to add lots of mature compost prior to planting. A starter mix of equal parts perlite, vermiculite and peat can work well, but you may need to add a little lime to neutralize the acidity of the peat. Mixes like this tend to work well for germinating seeds but you will need to transplant young seedlings into another pot with fertile garden soil before transplanting outdoors. Coconut fiber also works well for starting many seeds.
If you are direct sowing seeds into an outdoor garden bed, prepare your soil well in advance. Test it to be sure the pH is suitable for the vegetables you intend to plant. Till thoroughly and deeply, removing any debris like rocks and twigs. Add lots of mature compost.
SOW SEEDS CAREFULLY
Sow seeds into moistened soil or mix. Follow instructions on your seed packet for specific depth. Some seeds are finicky and will not emerge if sown too deep. Sow enough seeds to be able to choose the healthiest seedlings and thin them later.
KEEP SOIL WARM DURING GERMINATION
Some seeds will not germinate if the soil is too cold or will not bear fruit if the seeds were chilled. Most vegetable seeds germinate well in soil around 70° F. Use a heating pad and gauge the soil to be sure temperatures are ideal. Once seedlings have emerged, you can remove the heating pad. When direct sowing seeds into your garden, use plastic mulch to keep the soil warm. This can help extend the growing season. If kept snug to the ground, clear plastic mulch will retain more heat and keep weeds down just as well as black plastic.
KEEP SEEDS MOIST
Seeds will not germinate if they dry out. Keep the soil moist throughout the germination process. Mixes can soak up water from a tray, but a spray bottle or light, frequent watering works well. Do not let the soil get muddy; roots will not tolerate being soggy once they begin to sprout. You can also wrap you starter trays with plastic wrap to maintain constant moisture. Keep an eye on it and remove the plastic at first signs of germination.
PROVIDE LOTS OF LIGHT
As soon as seedlings begin to emerge, provide lots of light. When starting seeds indoors, a south-facing window is almost always preferred. Seedlings need 12 hours or more of light per day and as much direct sunlight as possible. Supplement with a grow light, suspended about 2 inches above the plants, whenever possible. Make sure you raise the light as the seedlings grow taller. If seedlings do not have enough light they will become weak and spindly. Weak seedlings are more susceptible to transplant shock and may bear small, less flavorful fruit.
REPOT AS NEEDED
If your seedlings outgrow their container, they should be transplanted into a larger one. If winter frosts last longer than expected, this may be necessary. Plan to have a medium sized container for each seedling just in case transplanting is delayed.
Know the age of your seeds. While many seeds are good for years if not decades, some plants will need to be grown from fresh seeds each year. Label any seeds you save with the type and date. If you don’t keep the original seed packet, you may want to write down the sowing instructions as well.
STORE SEEDS PROPERLY
Seeds should be kept in a cool, dark place with low humidity. Seeds that are not stored properly will lose viability even when they’re supposed to last for years. Keep them in a zip lock bag to help maintain dormancy. Test older seeds before planting. Most seeds can be tested by putting a few in a container of water for a few hours. Live seeds generally sink to the bottom while dead seeds will float to the top, though this method is not 100% accurate.
GOOD DRAINAGE AND AIRFLOW
Two of the most important elements of proper seed germination are good drainage and aeration. Without these two conditions, fungal diseases can easily develop. Be sure to add really good drainage holes when converting something into a grow container. Indoors, use a fan to provide good airflow in and around the seedlings.
To keep your seedlings strong and healthy they need to grow evenly. When starting them in a window, they’ll need to be turned daily to ensure proper, even growth. This can even be helpful when growing under lights. Give them at least a quarter turn every day.
ENCOURAGE STRONG STEMS
Give your seedlings a gentle brush of the hand every now and then. This will help to encourage strong stems.
Provide nutritional support as soon as seedlings begin to emerge. If you are growing in a fertile soil enriched with compost you may not need to fertilize until after you transplant, but seedlings grown in soilless mix or left in containers too long will need a regular feeding from a liquid organic fertilizer.
HARDEN OFF SEEDLINGS
Before setting your seedlings into their outdoor garden space (beds or containers), they’ll need to be assimilated to their new environment to avoid transplant shock. Set them outdoors for just a few hours per day, increasing the time each day for about a week. After a week, leave them in their containers outdoors overnight and set them into the soil the next day.