If you are looking for signs that it’s time to start seeds indoors for the spring garden, look no further than your curbside mailbox or computer inbox. It’s time to pot up when the seed catalogs show up.
While starting seeds indoors might seem like a challenge, the information on the back of each packet will answer almost any question you might have about how to grow that particular variety. That’s where you’ll find such valuable information as how deep to plant the seed, how long it will take to germinate, transplanting guidelines and other planting tips.
To help you get started on an indoor winter gardening project, here is a general guide for selecting and growing seeds in your home.
What to grow from seed
Check the catalog or the back of the packet to see if the seed should be sown directly into the garden. Some seeds, California poppies and wildflower mixes for instance, germinate easily and can be planted outdoors.
When to start
The first thing to determine is your last frost date. If you don’t know it, contact your local agricultural extension office. Then look on the packet for the number of days to germination and count backwards.
As a general rule for vegetables, herbs take a long time to sprout and beans and peas that like to climb should be planted last since they will want support, which can be provided more easily in the garden than indoors.
The goal is for the seeds to sprout, be growing well and ready to transplant into the garden after the danger of frost has passed. Because weather can be variable, some gardeners prefer to wait a few days or perhaps a week or two after the last frost date to plant the seedlings outdoors.
How to pot
Soil blockers create blocks of compacted soil with no plastic around them. (Photo: Ladbrooke SoilBlockers)
Instead of using plastic plant pots, which might be rejected by a recycling center and end up in a landfill, consider using an environmentally-friendly soil blocker. A soil blocker makes cubes of compressed potting soil with an indention for the placement of the seed. Because air can reach the roots much more effectively in a pot-less block of soil than in a plastic pot, the “air-pruned” roots in a soil block grow more vigorously than those in a pot, stay within the soil block and don’t suffer significant transplant shock when planted in the garden. A soil blocker that makes four two-inch cubes can be found at organic gardening stores or online sites, sometimes for under $30.
Here’s how to use them:
Select a potting mix for seeds at your local gardening store. This should be a fine, not chunky mix. If the mix doesn’t include fertilizer, add a granular seed-starter fertilizer at the rate of one cup to a 20-30 pound bag of mix.
In a plastic tub, mix the potting soil with water to the consistency of oatmeal.
Press the soil blocker into the mix until the mix fills the soil blocks.
Release the soil blocks into a 13x9x2 aluminum cake pan (some large box stores sells these for less than $1). A pan will hold four rows of soil blocks.
Place a seed in the indention in the top of the soil block.
Cover the seed with worm castings or potting soil.
Mist the soil blocks and keep them damp. You can add water from the side of the blocks, but don’t hit them with a stream of water.
Place the trays of soil blocks near a window that gets good light.
Don’t let the soil blocks dry out and don’t worry if a moss-like green growth appears on them.
Plant the seedlings in the garden when they develop a second set of leaves and danger of frost is safely past.