Our Best Seed Starting Tips
If you’re starting a new garden, one of the first skills you will want to develop is starting garden plants from seeds. Buying garden seeds and starting them yourself costs less than buying starter plants. Even more importantly, seed starting offers far more variety and flexibility in terms of plant varieties and timing. Garden centers only carry a few varieties of the most popular items. On the other hand, seed suppliers offer dozens of varieties of the most popular crops, like tomatoes, plus numerous crops that simply are not available as seedlings. Starting your own seeds also lets you determine when transplants will be available for your garden, rather than hoping the store will have what you need when you need it.
Starting seeds is not complicated. But it takes a basic level of skill to produce strong, healthy garden seedlings that will resist transplant shock and produce an abundant crop. Follow these tips to help ensure a robust start to your garden.
Start with Fresh Seeds
The seed itself makes a huge difference, and freshness is the first important component. Before purchasing seed, look on the back of the packet for the “packaged for 20xx” year. Although the seed may be a couple of years old, as long as the year stamped on the packet is current, you can be assured that the batch of seed in the packet passed the latest germination testing.
Use High-Quality Seeds
Try this experiment. Next time you go to your home improvement store or big box retailer, buy a pack of the cheapest seed you can find – let’s say Detroit Dark Red beets. Then go to an independent garden center or online to a premium seed company and buy a pack of Detroit Dark Red beets. Open both packets side by side. The cheap seed will likely be of varying sizes, possibly colors too, and may have a fair amount of chaff in with the seeds. The premium seed will likely be more uniform in size and very clean.
Next, perform a simple germination test. Keeping the two batches of seed separated, fold a sample of each into a wet paper towel then place each towel into a labeled zip-lock bag and close them. Place the bags on top of your refrigerator for a week, then open them and observe the results. Over the years, I have been more than satisfied to pay a few cents more for consistent, high-quality seed.
Pre-soak Seeds Before Planting
Anything large enough to handle individually will benefit from an overnight soak prior to sowing. This pre-soak helps to break the seed’s dormancy, and reduces the germination time by several days. My process is simple: place the seeds in a bowl and cover with tepid water. The next day, strain the seeds out of the water with a fine colander and pour them out onto a towel or coffee filter to blot the excess water. At this point the seeds are ready to sow in seed trays or directly into the garden.
Start Seeds Indoors
When you start seeds in trays indoors, you can control the germination ane early growing conditions. It leads to more rapid, uniform growth, reduces the need to thin, and eliminates weed competition. If you sow a few extras in the trays, you have the opportunity to select only the best seedlings to transplant into the garden. Then, the garden will be full of only the strong, healthy specimens because no “duds” made it that far.
Use Soil Blocks
Soil blocks changed my outlook on seed starting. I make blocks with a specialized tool called a soil blocker from real garden soil (along with some other good ingredients), not a sterilized mix. The seedlings that come out of this system are robust and experience little to no transplant shock when planted out in the garden. This is a more advanced technique that takes even more time, but if you want the best possible outcome with the least amount of waste, it’s worth the time and effort.
Provide Bottom Heat
Most garden seeds sprout best at temperatures 68-75 degrees. Colder temperatures lead to inconsistent germination and leggy plants. The soil temperature is more important than the air temperature. Place seed starter trays on top of the refrigerator, water heater tank or above (not directly on) a radiator. You can purchase electric seed starting heat mats for this purpose as well.
Seeds occupy a shallow position in the soil, where they are susceptible to drying out. Wet-dry cycles lead to inconsistent germination and die off in young seedlings. To eliminate wet-dry cycles, cover seed starting trays with plastic until the seeds germinate. Once the seeds sprout, loosen the cover to improve air circulation. Remove the cover after the seedlings produce their second set of leaves.
Give Young Seedlings 12 to 14 Hours Light Per Day
Starting seeds indoors has a major limitation: light. Light-starved seedlings grow thin, weak stems and pale, misshapen leaves. One solution is to supply artificial light two-inches above the foliage. I inexpensive grow light on a timer. Bright, close-up light makes seed starting possible even in a closet or basement. Natural sunlight is even better. If you have a brightly lit room with south-facing windows, that is an ideal place to start seedlings.
Keep Them Moist, Not Wet
For the first week or so after germination, the plants may not need much water. An occasional mist will suffice. As transplant time approaches, seedlings may need water twice a day. Use both the soil surface feel and the weight of the tray as your guide for watering. If the surface is crusty, but the tray feels heavy, misting is probably enough. When the tray is light and the soil crusty, the plants need a thorough watering to re-hydrate the roots.
Harden Off Seedlings Before Transplanting
Transplant shock can damage or kill young seedlings if the conditions in the garden are vastly different from the environment where they’ve been growing. Gradually move the seedling trays from the protected, artificially lit indoor environment to the full sun, garden environment in the last week or two before transplanting. Begin the process by moving them to a shaded outdoor location for just an hour or two, then increase the exposure and duration incrementally each day. Be sure to closely monitor soil moisture during this time.
See how to Hardening Off Seedlings For Planting.
Start Directly In The Garden
Some crops perform best when they are sown directly in their permanent garden home. Prepare the seed bed a couple of weeks ahead to allow any weed seeds to germinate, lightly cultivate the bed immediately before planting to remove weeds. Soak the vegetable seeds for 24 hours before sowing to promote fast, uniform germination. Sow the seeds and water them in. Water lightly every day until the seeds sprout. Then gradually increase water volume and decrease frequency.
Gardens with heavy clay soil need help. Use vermiculite or compost instead of soil to cover seeds after sowing. These lightweight, absorbent soil amendments hold moisture without hindering the young seedling’s upward progress.
Don’t Forget to Thin
Sowing seed directly in the garden demands two things: initially sowing more densely than you wish the plants to grow, and thinning the young emerging plants to the proper spacing. Neglecting the thinning part is setting yourself up for failure. Crowded plants compete for nutrients and water below ground, and sunlight above. If left in place, a thick stand of plants may not produce much. Once thinned, those remaining will grow beautifully.
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