Starting vegetable seeds indoors is one of the most exciting parts of spring for me. After months of enduring a dreary, cold winter, it’s invigorating to pull out my grow lights and seed trays and get started on a new growing season. Starting seeds indoors can give you a head start on the growing season and can also help you get the most out of your garden space. When I first started indoor seed starting, I had a modest setup, but over time, I gradually upgraded my tools and experimented with different methods, from jiffy pellets to full tray seeding and starter pots. In this blog post, I’ll be sharing my experiences and what has worked best for me. I’ll also discuss my goals for improving my system because when it comes to gardening, there’s always something new to learn!
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Choosing the right seeds
The first step in starting seeds indoors is to choose the right seeds. Make sure to choose seeds that are well-suited for your climate and growing conditions. You can find this information on the seed packet or by doing some research online. Additionally, make sure to choose seeds from a reputable source to ensure their quality. I purchase seeds from a few different companies but my #1 seed company has always been High Mowing Organic Seeds. They produce only the highest-quality organic seeds with fantastic germination rates!
Timing
To determine the appropriate time to start your seeds, the first step is to find your last frost date. Almanac.com allows you to search for this information using your zip code. Once you have determined your last frost date, refer to the instructions on each seed packet to determine how many weeks before that date you should sow the seeds.
To simplify the process, gather all of your seeds and create a sowing calendar by counting back from your last frost date. Consider grouping seed packets with similar sowing times to make it easier to keep track of which seeds need to be planted each week. By doing this, you can ensure that all the seeds for a particular week are sown at once and it saves you some time.
Sowing
Gather all of your seed starting supplies and prepare your growing space whether it be metal shelving or a table in a sunny window. I go over all of the supplies you will need to start your seeds indoors.
To begin the planting process, start by hydrating the soil. The soil should be moist enough to clump together when squeezed, but not excessively wet.
Follow the instructions on each seed packet to determine the appropriate planting depth, but as a general rule of thumb, plant the seeds as deep as they are wide. Cover the seed with a layer of seed starting mix and gently press down.
If you are using a tray, consider sowing two seeds per cell in case one fails to germinate. If both seeds germinate, identify the stronger seedling and gently trim the other at the soil surface. Certain seedlings, such as onions, can tolerate crowding, so you can sow several seeds per cell if necessary. Don’t forget to clearly mark your seedling, I like to take a picture as well in case the markers get moved around.
Germination
While seeds do not need light to germinate, is important to maintain consistent moisture and warmth. I suggest placing your seeding tray on a heat mat right after planting. Covering your tray with the clear cover that came with your seed tray or a piece of plastic wrap will help keep the soil moist. Different seeds will germinate at different rates but the seed packet should indicate how long this process should take. Once the seedlings have germinated, you can take them off of the heat mat, remove the cover, and place them under your grow lights.
Matinence
Now that your seeds have germinated you will need to keep an eye on a few key factors to ensure healthy plant development.
Light: You want to keep the grow lights as close to the seedlings as possible but not touching. As they begin to grow, you will need to adjust the height of your grow lights. Seedlings need 14-16 hours of light each day. You can put your lights on a timer to or manually turn them on and off daily.
Watering: Water your seedlings regularly, but be careful not to overwater them. Water only when the top of the soil feels dry. Overwatering can lead to damping-off disease, which can kill your seedlings. Always water your seedlings from the bottom if possible. Simply pour about a half inch of water into the base of the tray. If you are using pots or recycled containers with drainage holes, place them on a rimmed baking sheet and add water to the sheet pan.
Air Circulation: Provide good air circulation around your seedlings to prevent mold growth and other diseases. You can use a small fan or simply open a nearby window if it’s not too cold out.
Fertilizer: Feed your seedlings a balanced fertilizer once they develop their second set of leaves. Use a diluted fertilizer solution to avoid burning the delicate roots. I recommend Organic Rev to help support a strong root system. For help in determining if your seedlings are lacking in nutrients, check out my guide on Fixing Nutrient Deficiencies in Seedlings.
Temperature: Keep the temperature around your seedlings between 65-75°F. Avoid exposing them to drafts or sudden temperature changes.
Potting up
After some time, your seedlings will outgrow their initial growing cell. You want to keep a close eye on this because they can get rootbound. Seedlings should be potted up when they appear to be outgrowing their space or have grown their first set of true leaves. Prepare a new, larger container, fill it with moistened potting mix, and create a small hole for the plant. I suggest selecting a pot that is at least as tall as the plant. Gently remove the seedlings from their current container, being careful not to damage the roots. If the roots are tightly packed, you can loosen them up a bit with your fingers. Water your seedlings well after transplanting, making sure the water is evenly distributed throughout the pot, and place them back under grow lights or in a sunny location.
Hardening off
As your last frost date approaches, it’s important to consider the hardening-off process for your plants. This involves gradually acclimating them to the outdoor environment after being started indoors, preventing shock, and preparing them for life outside. To begin, I recommend starting this process approximately 2 weeks before transplanting into the garden or outdoor containers.
To harden off your plants, gradually increase their time outdoors each day, starting with just an hour and slowly increasing the duration. Start by exposing your plants to morning or late afternoon sun, and gradually increase the amount of direct sunlight they receive over time. It’s important to pay attention to the weather conditions as well, providing shade during extreme heat and shelter from high winds. Your plants will require more water during this period so keep an eye on the soil.
Transplanting
After all your hard work, your plants are finally ready for the transition to the outdoors. When it’s time to transplant, it’s important to handle your seedlings with care to avoid harming their delicate roots. Begin by digging a hole in the soil that’s slightly bigger than the root ball, and then gently place your seedling in the hole, making sure it sits at the same depth as it did in the container. This will help your plants settle into their new environment and continue to thrive.
Happy Growing!
