Guide to Seed Starting: Part 1

Spring is approaching. It’s almost time for us to start seeds here in zone 4! That first smell of soil and holding those tiny seeds causes a dramatic awakening in me; as if the frozen walls of winter that surround me are bursting open, and the strong light of the sun streams through… It’s a time full of hope, wonder and life.

If you haven’t yet ventured into the amazing world of seed starting, this post explains several reasons why it’s a better beginning for you and your garden. Ok, so let’s say you’re on board – you’re going to give seed starting a go. Let’s also say that you already determined what you’re going to grow in your garden this year, and purchased your seeds. Then the big questions are, When do I start the seeds? Which ones? Where? How? For how long? Ok, ok, so there are lots of questions to answer, but it’s really not so overwhelming. Stick with me for this seed starting series, and you’ll have a sure footing as you start your garden from seed.

This is Part 1 of the Guide to Seed Starting series. Catch the rest of the series here: 
SUPPLIES: Part 2 
PLANTING the seeds: Part 3
SEEDLING CARE and TRANSPLANTING: Part 4

When to start your seeds indoors

1. Determine your Spring frost date.

This date tells you when is the average date for the last frost of springtime in your area. It’s a very important date for gardeners because it means our frost-sensitive plants are (likely) safe to be outside! This date is also the key to determining when you will start your seeds indoors. Some resources like this one, give you a single date to go off of if you just type in your zip code. This is straightforward and easy, but technically it isn’t the whole story. If you like to have a little more control over which temperature you’re going off of (36 vs. 24 degrees, for example), or you’d like to choose the level of probability or risk you’re willing to take, you can go to this website which does an excellent job of presenting the info from the National Climactic Data Center in a more user-friendly way.  If your location is not represented in this data, you may find such information from your local extension office or gardening center.

2. Read your seed packets.

Not all of your seeds will need to be started at the same time. Some seeds tolerate cooler weather, other seeds take a long time to germinate, so be sure to check the back of your seed packet. Here, it should tell you how many weeks before the last spring frost you should start those particular seeds. You might find it easiest place your seed packets in envelopes according to their start date: 8 weeks before your frost date, 6 weeks before, 4 weeks before, etc. If this information is not on your seed packet, you can find a comprehensive guide for each plant type here.

3. Mark the weeks before your frost date out on a calendar.

The most straightforward way I’ve come up with for calculating when to start the various seeds is to mark the Spring frost date on my calendar, then count backwards (writing it on the calendar) from that date. That way, when the time approaches, I can easily see, “ok, time to sow those pepper seeds!”

Deciding which seeds to start indoors

Not all of your seeds will appreciate or need the head-start indoors. Plenty of seeds can be set aside for direct-seeding into your garden beds. Just think, you wouldn’t transplant each individual carrot! To help organize your seed starting, I’ve created a chart of some of the most common vegetables and herbs, indicating if they ought to be sown indoors, outdoors, or either. Where both are an option, choose indoors to get a head start on the season. For example, I could direct sow my lettuce outside, but I’m eager to have some garden greens after our long winter, so I start them indoors and we’re eating salads sooner. However, I tend to direct seed plants that are sensitive to transplanting because I don’t use dissolvable planting pots. Or perhaps, you’re limited on space under your grow light, and need to direct sow as much as possible.

Plant	Sow Indoors	Sow Outdoors
Artichoke	X
Arugula	X	X
Asparagus	X (from seed)	X (from crown)
Beans		X
Beets		X
Broccoli	X	X
Brussels Sprouts	X	X
Cabbages (all types)	X	X
Carrots		X
Cauliflower	X	X
Celeriac	X
Celery	X
Collard Greens	X	X
Corn		X
Cucumber	X (sensitive to transplanting)	X
Eggplant	X
Endive		X
Fennel	X (sensitive to transplanting)	X
Jerusalem Artichoke		X
Garlic		X
Ground Cherry	X
Kale	X	X
Kohlrabi	X	X
Leeks	X	X
Lettuce	X	X
Melons	X (sensitive to transplanting)	X
Mustard Greens	X	X
Okra	X
Onions	X (seeds)	X (sets)
Pac Choi	X	X
Parsnips		X
Peas		X
Peppers	X
Potato		X
Radiccio	X	X
Radish		X
Scallions	X	X
Rutabaga		X
Shallots	X (seeds)	X (sets)
Spinach		X
Squash (Summer, incl. Zucchini)	X (sensitive to transplanting)	X
Squash (Winter, incl. Pumpkin)	X (sensitive to transplanting)	X
Swiss Chard		X
Tomatillo	X
Tomato	X
Turnips		X
HERBS
Basil	X
Chive*		X
Cilantro		X
Dill		X
Lavender	X
Mint*	X	X
Parsley		X
Oregano*	X
Sage*	X
Thyme*	X	X
* Perennial herbs are easiest to grow from a cutting of an existing plant

As always, I advise with the caveat that some of this could be different if you climate is drastically different from mine. If you never get frost in your location, you might be able to direct seed some plants that I need to start indoors (and I should visit your location about now!).