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Trying to figure out when to start fall seeds even though it’s blazing hot outside? In this article, we’ll help you figure out exactly when to start your fall seeds so you can have a successful fall (or winter) garden!

When to start fall seeds and why you should give cold weather gardening a try 

It’s scorching hot outside, thunderstorms are frequent, and piles of fresh fruits & veggies are coming out of your garden. That means it’s almost time to start your fall seeds!

Ground cherries - a delicious summer fruit that grows best in the full heat of summer.

Ground cherries – a delicious summer fruit that grows best in the full heat of summer.

It might not feel or taste like it at the moment, but for most areas of the country, July through September are the months you’ll want to start your fall/winter seeds indoors to transplant out in your garden 6-8 weeks later.

Of course, you can always direct-sow your fall/winter seeds in your garden underneath the cooling shade of your larger summer annuals (tomatoes, peppers, etc) if you’d prefer. That’s what we often do with kale, lettuce, and other salad greens.

However, we’ve found that we usually get much better growing results with fall crops such as Brussels sprouts, bok choy, and cabbage when we start them indoors. That’s because they get to enjoy six weeks growing in a temperature-controlled environment and have a big jump start on the fall growing season before we transplant them outdoors into our garden in late summer.

Why Should You Garden In the Fall or Winter?

Gardening isn’t just a warm weather activity. In fact, most gardeners we know who try cool weather gardening actually end up liking it better than summer gardening!

A gorgeous bok choy from last fall.

A gorgeous bok choy from last fall.

Why? There are far less weeds, pest insects, or soil pathogens and diseases during the cool months. Plus cooler soil temperatures means less water evaporation, so your irrigation needs are minimized.

Oh, and perhaps the most important reason to garden in fall and winter? Cool season crops are delicious — even more so when they come fresh from your own garden!

When To Start Fall Seeds

When should you start your fall and winter seeds? That answer will depend on:

  1. What Agricultural Zone you live in,
  2. When your first frost date is, and
  3. The “days to maturity” of the particular seed variety you’re growing (this info should be on your seed packet).

Once you know this info (above), simply count back from your first frost date based on your “days to maturity” to determine when you should start your seeds. 


Let’s say you have a broccoli variety that takes 100 days to mature, and your first frost date is November 15. That means you’ll need to start your broccoli seeds around mid-July. Note: You do have more wiggle room if: a) you’re growing frost- and freeze-tolerant plants, and/or b) you use low tunnels in your cool weather garden.

(If doing the math seems too complicated, scroll down the page to our downloadable fall seed starting calculator, which makes it super easy to figure out when to start fall seeds of pretty much any variety.)

Many cool weather crops can easily survive uncovered in sub-freezing temperatures.

Many cool weather crops can easily survive uncovered in sub-freezing temperatures.

What plants grow best in the fall and winter?

There are also plenty of fall/winter veggies that will continue growing even in sub-freezing temperatures with no protection. As mentioned previously, you can be more aggressive about starting those seeds closer to your first frost date if you’d like.

Here’s our full  list of our top recommended fall and winter garden plants.

If you’re sifting through seed packets, look for “cold hardy” varieties, or other info on the packets indicating the variety’s frost and freeze tolerance. 

GrowJourney seed packets contain icons designed to make it easy to instantly tell the relative hardiness of the seeds inside.

Something else to look forward to: a frost or a freeze will sweeten the flavor of cold hardy veggies when the plants’ sugars become more concentrated as a natural antifreeze against the cold! 

Beet roots taste amazing after a fall frost.

Beet roots taste amazing after a fall frost.

Downloadable Fall Seed Starting Calculator

To make it easier for you to figure out when to start fall seeds, we’ve created a fall seed-starting “calculator” that you can use to figure out when to direct sow your fall seeds or transplant your fall seedlings into your garden (if you started them indoors).

View and download the calculator as an Excel or Google Doc spreadsheet. (Note:.xlsx is recommended if you’re using MS. Excel & .csv is recommended for Open Office.)

Get Growing!

Keep enjoying your sumptuous summer produce, but don’t forget to think and plan ahead for all the healthy, delicious produce you can grow in your fall and winter garden!

Like what you’re reading? Here are more winter gardening tips to help you take your cold weather gardening skills to the next level.