Whether you’re sowing one packet or dozens or hundreds, it just makes sense to make sure you have everything you need on hand so you can sow whenever the time is right.
If you plan to grow more than a few kinds of seed each year, I highly recommend creating some sort of list or chart of the seeds you have on hand for sowing. I have found it invaluable for staying organized, planning my sowing sessions, and keeping track of my sowing results.
Once I think I’m done most of my seed orders for the season, I make a chart of what I’ve purchased and which saved seeds I plan to sow. (I usually rummage through my box of old seeds once a year too, just to see what’s in there. I rarely sow entire packets of anything, so I have probably hundreds of partly-used packets. Most still germinate well even after 3 or 4 years, and I’ve had some sprout even after 8 or 9 years. It’s very helpful to have a backup supply like this in case one year’s sowing doesn’t make it to seed stage for some reason, or if I forget to buy new seeds of a must-grow.)
At some point in late January, I go through my to-sow box to start organizing the packets by planting time. I used to do this once, separating the different batches into smaller boxes labeled by the planned sowing date. I so enjoy pawing through my little seedy treasures, though, that I now go through my main box each time, pulling out what I want to sow then and putting everything else back. I do rounds of sowing every 10 days or so, starting in late February with slow-germinating annuals and perennials, as well as those that benefit from an extra-long growing season, like dahlias. In early to mid-March, I start outdoor sowing for cold-tolerant things like poppies, peas for eating, and sweet peas and indoor sowing for most annuals. In late March to early April — which I figure is about a month before the last-frost date here — it’s time for indoor-sowing fast-growing annuals, such as zinnias and morning glories, and outdoor-sowing more annuals and edibles.
While it’s tempting to rely on specific guidelines like “sow 6 weeks before your last frost date,” I find that doesn’t always work for me. For most of my gardening experience, I thought of Mother’s Day as our benchmark for planting out annuals, knowing that we could still have frost, or at least chilly weather, even until Memorial Day. Just this year, though, I saw a reference to April 19 as our last frost date, and I realized that yes, the growing season has been starting earlier and earlier over the last decade. Still, there are often unexpected frosty or freezing nights until late May, and that makes the whole timing game a bit of a gamble.
In general, I know I tend to start my seeds indoors too early, and then I run into problems because I have a limited amount of indoor space for seeds and seedlings. Based on questions I get from customers, I know I’m not alone in always wanting to jump into spring sowing too soon. My advice is that if you’re in doubt, you’re better off starting a week, or even a few weeks, later rather than earlier. Granted, a few things may end up not flowering much or setting seed if they get a late start, but that’s less of a problem than dealing with stressed, root-bound, crowded seedlings indoors, or planting them out too earlier and then having them be killed or stunted by cold.
Unless you’re sowing seeds directly in your garden, you’ll need some sort of growing medium and containers to put it in. I’ll discuss that more in Sowing Seeds in Pots and Alternatives to Sowing in Pots (coming soon).
Some kind of light source is important too, if you are starting your seeds indoors. You may be able to get away with a full-sun windowsill for one or a few pots, but some sort of dedicated light usually provides much better results. I used to use 4-foot shop lights with fluorescent bulbs, but trying to find a place that will dispose of the burned-out bulbs safely is a real hassle, so I now use 4-foot LED light fixtures instead. These days, it’s easy to find many options for light setups online.
A heat mat meant for seed-starting can be very useful for providing steady heat to keep the growing medium warm and encourage quick sprouting for heat-appreciating seeds.
Whether you sow indoors or outdoors, trust me: You need some kind of labels to indicate what, where, and when you sowed each kind of seed. I like to note the seed source too. You may think you remember, but you won’t. Trust me on this!
I used to use plastic plant labels exclusively and still do reuse some old ones, but this year, I am trying wooden “craft sticks” (a.k.a. Popsicle or ice cream sticks) instead, writing on them with a fine-tipped permanent marker, and it seems to be working out well so far. They are easy to find (in craft stores or online), much less expensive than plastic labels, and biodegradable, which is ideal for annuals (no more picking up so many old bits of plastic at the end of the growing season). I still prefer pencil writing on plastic tags for seed pots that I know will be outside through the winter, or for many months, though, for more longer-lasting identification.