How To Start Seeds
With the right set-up, Seed Starting isn't so hard
"Seed starting is easy," an experienced gardener may have told you. But if you've ever tried it, you might be inclined to use the Italian expression "sembra facile," meaning something seems easy when it's not.
This is the easy part: Seeds want to grow, and given the right conditions they'll take care of themselves.
This is the hard part: Getting the conditions right, and having the patience and diligence to keep them steady for a few months. Here we'll talk through everything you need to have success starting your plants from seed.
Though there are some special cases, most seeds like the same thing. In order to sprout, they like to be moist, but not wet, without ever drying out, and to be kept around room temperature for a few days to a few weeks. Once they've sprouted, they like lots of light, along with that even moisture and mild temperature.
Some seeds prefer to be planted straight out into the garden (usually the big seeds like beans and pumpkins), while many prefer to be started in pots. Here we'll be talking about the seeds you start in pots. Your seed package will tell you how best to start each particular kind of seed.
Before you start
You'll need to consider 6 elements and gather all the gear before you get started: Seeds; seed-starting mix; containers; water; light; and heat. Here we discuss each one in detail.
With literally hundreds of places to buy them, and thousands of varieties available, choosing seeds can be overwhelming. But it's also one of my favorite activities, "fantasy gardening" as I flip through seed catalogs imagining unusual, beautiful and tasty plants thriving in my garden. (Admittedly, the reality is more modest.) Some of our favorite places to get seeds are:
- Hudson Valley Seed Company
- Baker Creek Heirloom Seeds
- The Living Seed Company
- Redwood Seeds
- Johnny's Seeds
And if that's too much choice, we have a small selection of our favorites available here.
2. Seed Starting Mix
You can make your own, buy it from us, or find it at any garden center, but whatever you do, don't use regular garden soil, which is too dense and tends to have weed seeds in it. Seed mixes are light and airy, while also retaining moisture to help keep seeds evenly moist without getting soggy.
Look for peat-free mixes. While peat is a good medium for seed starting, it's a very unsustainable resource, being essentially a miniature old-growth forest. And mining peat releases lots of trapped CO2 into the atmosphere.
It's a good idea to mix a bit of your garden soil into your seed starting mix (about a tablespoon for every 4 cups), to inoculate it with the soil bacteria your plants will live with when they go out to the garden. (More on that here)
You can use anything from an egg carton to a reused six-pack to one of our self-watering planters. The diy methods are cheap and compostable, or are reusing material that would otherwise go to landfill, but they require diligent, careful watering (see below) and can be a bit grubby looking. Our planters cost more, but last a lifetime, look nice, and you only have to remember to water once a week.
If you're watering by hand in a diy pot, you'll need to water very gently, a little bit every day, sometimes twice a day in warm weather. To do this, you'll need a fancy watering can with teeny holes that waters very gently, a diy version of the same (think plastic bottle with holes poked in it with a pin) or a lot of patience as you dribble water slowly with a measuring cup. Keep the seed mix moist but not wet.
One of the biggest mistakes beginners make is not giving seedlings enough light, causing them to stretch tall and skinny looking for more light. This makes for weak baby plants prone to disease and tipping over.
You'd be surprised by how much light seedlings want. Outdoors they want a protected spot with full sun, like a greenhouse or cold frame. Indoors, they want a window with 8+ hours of full sun, or a proper grow light for 14 hours a day.
Some seeds will only germinate in the light, and must be planted on the surface. Others only sprout in the dark. Most don't mind either way.
Most seedlings will grow just fine at moderate indoor temperatures, or even mild outdoor temps, but some are fussy about temperature. The most notorious are warm weather veggies like tomatoes, basil, and especially peppers. They will sprout happily at 75F, but will be sluggish or won't sprout at all at lower temperatures. Most nurseries sell waterproof mats to help get warm-loving seeds going.
Other seeds need a period of cold to sprout. Called cold stratification, this process mimics winter. When the cold ends, the seed thinks it's spring and time to sprout. It sounds complicated, but is actually straightforward: Plant your seedlings in their containers and stick them in the fridge for about a month, making sure to keep them moist. When you take them out, leave them at room temp to sprout as usual.
Planting Seeds, Step-By-Step
Before you begin, take a moment to look up what conditions your seeds prefer (temperature and light requirements). It should be on the packet, or very easy to find online.
- Fill your containers with seed starting mix
- Bury your seeds to the depth indicated on the seed packet
- Water them in gently. A light sprinkling of water helps ensure that the seeds are in contact with the soil.
- Heat or cool if needed.
- Keep them lightly moist (about the dampness of a wrung-out sponge) and in bright light until 2-4 sets of leaves develop. For some seeds this is a couple weeks, for others this can take several months.
- Transplant to a bigger pot, or out to the garden.