When To Start Seeds For Your Organic Garden

It’s mid-April, and the snow is finally melting.  

I was beginning to wonder if Worcester would be the last place in Vermont to claim white hills and winter, but just a week ago I saw a robin hopping about outside the kitchen window, and knew spring had kept its promise.

We started our first round of seeds in late February, some of them destined to be cut for microgreens and pea shoots, others for planting out in the greenhouse.

But as the snow clung to the fields (as in, feet of snow), we were starting to question where we’d put the first outdoor plantings.  Springtime farming is a gamble in northern climates. We fill the greenhouse up as much as possible, but eventually, we need unprotected fields.  Eventually, we need the snow to melt.

That said, we don’t start all the seeds in March and April.

You don’t have to, either — succession planting will get you through the spring, summer, and fall with consistent harvests.

Still, spring is the time when we get most excited about starting seeds.  

While succession planting works for many crops, here in zone 4b, unless you have a greenhouse, the hot crops like tomatoes, peppers, and eggplants will likely be planted once.

When to start seeds

Deciding when to start seeds in the spring depends on the crop and your last frost date.  

The last frost date is in the spring, when you can expect the nights to be steadily above 32ºF, meaning your tender plants won’t be damaged by frost.  The first frost date comes in the fall, when you can expect to get the first frost of the harvest season.

Our average last frost date is Memorial Day, though last frost dates vary by region and altitude, and can be different within the same town.  Here on our hillside farm, for example, we can get a frost even when our neighbors a mile down in the valley won’t.

You can find your average last frost date here.

Once you have your last frost date, it’s time to calculate your seeding date.

High Mowing Organic Seeds has this handy planting chart, which tells you how many weeks before transplanting you need to start your seeds.

Let’s take break this down with a few examples:  

Say you’re planting lettuce, tomatoes, and basil, and you want to plant them outside on June 1st.

Lettuce needs 3 – 4 weeks before planting out

Basil needs 4 – 6 weeks

Tomatoes need 6 – 8 weeks

Counting backwards from June 1, you’ll get your seeding date:

Seed lettuce between May 4 – May 11

Seed basil between April 20 – May 4

Seed tomatoes between April 6 – April 20

If you’re succession planting throughout the summer, you can also base your seeding date off of your desired harvest date.

Each variety has a specific number of days to maturity (DTM), which you’ll find listed on the seed packet and in the seed catalog.  Sometimes DTM is based on direct-seeding into the garden, and other times it’s based on transplanting. You’ll also find this information on the seed packet and/or the seed catalog

Nevada Lettuce, a great variety for hot summer harvests, reaches maturity in 55 days when direct-sown into the springtime garden.  So if you want to harvest it on August 1st, you’d count back 55 days from that date to reach your planting date of June 14.

Farming and gardening is an art and a science.  

If figuring out successions and planting dates starts to boggle your mind, remember: spring is here, and it’s okay to follow your gut, too.  Oftentimes, we switch things around at the last minute based on the weather, pest pressure, or what bed is ready for planting.

So have fun, stay flexible, and start those seeds.  

What seeds are you starting this spring?  Let me know in the comments below.