Our Best Seed Starting Tips
For plenty of reasons, starting garden plants from seeds is an attractive option. It’s a lot cheaper per plant than buying even the smallest transplant. It offers the greatest number of varietal options. In order to perpetrate an heirloom variety, not only must the seed be saved, but it must be started the next season. Plus it’s the best way to know your garden intimately. There are probably more reasons, but that’s not what this post is about. This is about getting the most success out of seed starting efforts. Following these tips will help ensure a robust start to your garden project.
1. Use Fresh Seed
The seed itself can make 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.
2. Use High Quality Seed
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 fair amount of chaff in with the seeds. The premium seed will likely be more uniform in size and very clean.
Another observation can be made from 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.
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 can reduce the germination time by several days. My process is simple: place the seeds in a bowl and cover with tepid water. The next day I 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.
4. Start Indoors
Starting indoors allows control over the germination conditions (important for early starts on heat loving crops), helps seedlings outgrow weed competition, and greatly reduces thinning (helpful for tiny seeded plants like lettuce or cabbage). When the seedlings are ready to plant in the garden, the garden is full of only the strong, healthy specimens because no “duds” made it that far.
5. Use Soil Blocks
Soil blocks changed my outlook on seed starting. I make blocks 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.
6. Bottom Heat
Garden seeds sprout best at temperatures 70-75 degrees. Place them on top of the refrigerator, water heater tank or above (not directly on) a radiator. You can purchase seed starting mats for this purpose as well. Cold temperatures can lead to leggy plants.
Cover seed starting trays with plastic until the seeds germinate. Once the seeds sprout, uncover them.
8. The More Light the Better
Seed starting indoors has a major limitation: light. The best solution is to apply artificial light (I use a cheap fluorescent shop light) as close to the foliage as possible. Bright, close-up light makes seed starting possible even in a closet or basement.
9. Keep Them Moist…Not Wet
For the first week or so after germination, the plants won’t need much water. An occasional mist will suffice. As transplant time approaches, the seedlings may need water twice a day. Use both the soil surface feel and the weight of the tray as your guide for watering. The surface may be crusty, but the tray heavy, meaning that misting is enough. When the tray is light and the soil crusty, the tray may require semi-immersion in a tray of water to re-hydrate the roots.
10. Harden Off Seedlings
Before transplanting seedlings from their starting area into the garden, it is critical to harden them off, or prepare them for outdoor conditions.
See how to Hardening Off Seedlings For Planting.
11. Start Directly In The Garden
Some crops, root crops in particular, perform best when sown directly on their permanent garden home. Prepare the seed bed a couple of weeks ahead to allow any weed seed to germinate, lightly cultivate the weed bed immediately before planting garden seeds.
12. Cover Lightly
Gardens with heavy soil need help. Use vermiculite instead of soil to cover seeds after sowing. Vermiculite will hold moisture without hindering the young seedling’s upward progress.
13. 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.