The Planting Calendar: What to Sow and When
Everything counts back from one date: your last frost.
Here’s the secret that makes vegetable growing suddenly click. 🌱
You don’t need a complicated schedule or a shelf full of garden books. You need one single date, and everything else falls into place around it.
That date is your last frost, the point in spring after which a hard freeze is unlikely. Some crops get started weeks before it, some go in right after, and knowing which is which is the whole game.
Get that one idea, and you’ll sow at the right time, every time. Here’s exactly how it works. 🌿
Find your date first
Before anything else, find your local last frost date. It’s the anchor the entire calendar hangs off.
Search your zip code on the Old Farmer’s Almanac site, or check your state extension office. Jot the date down, because every step below is counted from it.
Sow seed, or start indoors?
The calendar uses two actions, and knowing the difference is key.
Tender, slow crops like tomatoes and peppers get a head start indoors because our growing season isn’t long enough for them from seed outdoors. Quick, hardy crops like radishes and beans are simply sown where they’ll grow.
Your schedule, counted back from frost
Work down this timeline from the top. The weeks are how long before, or after, your last frost date to take each action.
Onions. First off the mark, since they’re slow to size up from seed and need the long head start.
Bell peppers and eggplant. Heat-lovers that are painfully slow to get going, so they need weeks on a warm windowsill before the weather is ready for them.
Tomatoes, broccoli, cauliflower and kale. The big spring sowing. Tomatoes want warmth ahead; the brassicas are hardy but benefit from a strong, stocky start as transplants.
Lettuce and arugula. Cool-season leaves that shrug off a light frost. Start lettuce indoors for an early crop, or sow either straight outside as the soil wakes up.
Beets, radishes and spinach. Hardy roots and greens that actually prefer cool soil. Sow them straight into the ground while the weather is still chilly.
Carrots and potatoes. Tough enough to handle the last of the cold. Get carrot seed and seed potatoes in just before your frost date.
This is the line in the sand. The tender, warm-season crops cannot go out until the danger of frost has truly passed. Hold your nerve, even if there’s a warm spell.
Bush beans. Beans rot in cold ground, so wait until the soil has warmed a couple of weeks past frost, then sow them straight out.
Cucumbers. True heat-lovers. Only go in once the soil is properly warm, well after frost, or they’ll sulk and stall.
Why peppers come “before” frost but go out after
A crop’s place on the timeline is when you take the action, not when it goes outside.
You start peppers indoors 10 weeks before frost, but those young plants still only move out into the garden once the frost danger has passed. The early date is about sowing the seed, not planting out.
Every crop’s numbers at a glance
Once you know when to sow, here’s how to sow it. Depth, spacing, how many fit per square foot, and roughly how many days to harvest, for all sixteen crops.
Arugula
Beet
Bell Pepper
Broccoli
Bush Bean
Carrot
Cauliflower
Cucumber
Eggplant
Kale
Lettuce
Onion
Potato
Radish
Spinach
Tomato
Companion planting that actually works
Companion planting is full of charts promising which plants “love” each other. Here’s the honest truth most of them won’t tell you.
Most of it is folklore, not fact
The vast majority of companion planting charts are passed-down tradition rather than tested science.
When university extension services have reviewed the standard lists, they’ve found no scientific basis for most of the pairings. So be skeptical of any chart that tells you two plants are “friends” with no reason given.
That said, a handful of pairings do have real research behind them. These are the ones worth your bed space.
The Three Sisters
Corn, beans and squash grown together. The classic Native American intercropping method is genuinely well documented: corn gives the beans a pole, beans feed the soil, and squash shades out weeds.
French Marigold
Its roots release compounds that suppress root-knot nematodes in the soil immediately around them. A real, measurable effect, though only in that close zone.
Nasturtium with squash
Trialled and shown to reduce squash bug numbers, one of the more reliable pest-deterrent pairings you can try.
Alyssum with lettuce
Dotted through at roughly one plant per fifty, sweet alyssum draws in the predatory insects that eat aphids, protecting your lettuce for you.
Marigold, onion and nasturtium
This trio planted among brassicas reduced cabbage worm damage in trials. A smart combination to tuck around your broccoli and kale.
Common questions, answered
What exactly is my “last frost date”?
It’s the average date of the final spring frost for your area, after which a damaging freeze becomes unlikely. It’s an average, not a guarantee, so watch the forecast and be ready to cover tender plants if a late cold snap threatens.
Why start some plants indoors at all?
Our growing season isn’t long enough for slow, heat-loving crops like tomatoes, peppers and eggplant to go from seed to harvest outdoors. Starting them inside gives them a six-to-ten-week head start so they fruit before fall.
What does “days to harvest” actually count from?
For direct-sown crops, it’s counted from sowing. For crops you transplant, like tomatoes and peppers, it’s counted from the day you plant the seedling out, which is why those cards say “from transplant.” Add the indoor weeks on top for the true total.
Can I just plant everything after the last frost to keep it simple?
You can, and your warm-season crops will be fine. But you’ll miss the early window for cool-season crops like spinach, radishes and lettuce, which actually prefer the chilly weather and may bolt if planted too late. Counting back is worth the small effort.
One date, and you’re away
That really is the whole system. Find your last frost date, count back, and let it tell you what to sow and when.
Start simple this season with a couple of easy direct-sown crops like radishes and beans, then add the indoor-started ones next year as your confidence grows.
Go look up your frost date right now, while you’re thinking about it. Everything else follows from there. Happy growing. 🌱
