When to Start Seeds in Zone 7

If you’re like me, the first warm and sunny day of the year has you dreaming of spending days tending to your garden. While there’s nothing wrong with a bit of daydreaming, healthy plants won’t grow themselves! Starting seeds is one of the first steps to get your garden off to a great start.

The problem is that it can be difficult to know when to start different types of seeds. To help you out, I’ll cover when to start seeds in zone seven, so you have healthy seedlings to plant at just the right time. 

Where Is Zone Seven?

With the recent changes to the USDA Plant Hardiness Zone Map, zone seven now spans across the United States from coastal Massachusetts down to western North Carolina across to mountainous California and up western Washington. Some notable cities located in this zone include Philadelphia, Oklahoma City, Nashville, Albuquerque, Reno, Salt Lake City, and Boise.

What Is the Climate in Zone Seven?

Before we dive into climate, let’s get one important fact out there. While many people think USDA growing zones refer to a location’s number of frost-free days or summer temperatures, the growing zone actually tells us about the average low temperature. That means the low wintertime temperature is the only factor two locations in the same growing zone have to share.

All areas in this growing zone experience low temperatures between 0 to10°F (-17 to -12°C). Since these are average low temperatures, it’s possible that temperatures will drop below 0°F some years and remain above 10°F other years.

Outside of the average low temperature, the climate varies quite a bit between different locations in this zone. For example, Albuquerque, New Mexico regularly experiences temperatures above 90°F (32°C) in the summer but maintains low humidity. And while Richmond, Virginia, has cooler summers, it faces high humidity and rainfall. These are just two examples of zone seven climate—look up historical data in your area to gain a sense of what rainfall, temperature, and humidity to expect.

Determine Start Date

Even if you know how to grow beautiful seedlings, starting seeds at the wrong time can render these plants practically worthless. If you start seeds too early in the year, they’ll outgrow their containers before it’s warm enough to transplant them outdoors. And if you start seeds too late, the plants won’t have time to mature before crushing summer heat or fall frosts arrive.

So, how do you know when you should start your seeds in zone seven? When it comes to planting seeds in the spring, keep your average last spring frost date in mind. In this zone, the last spring frost typically occurs between mid-March and mid-April. I recommend looking up the last average frost date for your location to gain a more accurate prediction.

Once you’ve determined your exact average last frost date, figure out when you plan to add seedlings to your garden. Transplant cool-weather crops like broccoli and kale a few weeks before the last frost as long as you use row cover to protect plants from heavy frosts. However, wait a few weeks after the last frost to transplant summer plants like tomatoes, zinnias, marigolds, and peppers.

After determining your transplant date, it’s time to figure out when to start your seeds so the seedlings are ready at the right time. Look at the seed packet to learn the time it takes for a seed to grow into a seedling. For example, the ‘Sweet Banana’ seed packet instructs you to start seeds eight to ten weeks before transplanting.

Fall Gardening

Of course, you don’t just plant a garden in the spring! Adding a new round of transplants in the late summer and early fall allows you to harvest crops throughout the fall.  When you’re determining when to start fall seeds, remember fall and winter crops should be mostly mature by the time days dip below ten hours long. That means you should transplant seedlings one to three months before the last ten-hour day and start seedlings four to six weeks earlier.

Begin Seeding in Zone 7

Here, we’ll discuss when to begin seeding for spring, summer, and fall gardens.

When to Start Vegetable and Flower Seeds for Spring Planting

Since this zone deals with below-freezing temperatures for much of the winter, you’ll have to wait until spring to plant many seedlings outdoors. However, you can start seeds indoors in the late winter with the help of grow lights and heating mats. By the time the weather is warm enough to plant seedlings outdoors, you’ll have healthy plants ready for their new home.

When you’re determining your seed-starting schedule in the spring, the last frost date is the most important factor to consider. Since this date varies by about a month, I’ve included a range of ideal planting dates.

When to Direct Seed Flower and Vegetable Seeds Outdoors in the Spring

If you live in zone seven, you can get away with direct seeding a lot of your spring and summer crops. I recommended direct sowing all root crops as well as baby leafy greens like arugula and baby kale. While transplanting cucurbits like melons and cucumbers and summer flowers like sunflowers and zinnias helps you get a jump on your first plantings, I like to direct sow later successions of these crops.

Feel free to direct sow seeds any time within the following ranges.

Fall Planting

You can get away with planting two rounds of cool-weather crops like brassicas, fennel, and spinach. Starting a second round of seeds in the summer gives you seedlings that are ready to plant in the late summer or early fall.

Final Thoughts

Now that you know when to start seeds, it’s time to browse through seed catalogs and select a few new varieties to try growing. By starting seeds ahead of time, you’ll be ready to get your garden growing when warmer weather arrives.