Though we often think of spring as a good time to prep and plant a garden, you can actually start planning well before the snow melts and continue planting all the way until the first freeze in fall. If you live in a frost-free region, lucky you — you can garden year-round!
Climate Zones and Frost Dates
How do you determine the best time to prep or plant? The most reliable source is your local independent garden center, which can offer general growing guidelines for your particular climate.
You will also need to know what climate zone you fall into, as this information will help you select the proper plants for your area. The USDA Plant Hardiness Zone Maps are a trusted standby in the gardening world that divides the country into zones by winter lows. For a more accurate gauge of how well a plant will perform in your region, take a look at the Sunset Climate Zone Maps, which take into account the length of the growing season, the timing and amount of rainfall, winter lows, summer highs, wind, and humidity.
Next, you will need to know the first and last freezes in your region (also known as frost dates). Enter your zip code at Dave's Garden to pull up a handy chart that lists the likelihood of freezing temperatures in spring and fall, as well as the estimated length of your frost-free growing season.
Now that you know all these numbers and dates, what do you do with them?
Refer to your climate zone when choosing plants that will work in your garden (especially if you're ordering online and not from a local nursery). Certain plants are adapted to warmer climates, while others need cooler climates to thrive. This is especially important for perennial plants that may only be hardy to a certain zone before they succumb to heat or frost. That's right: just because they're labeled as perennial doesn't mean they'll survive year-round if you live in a particular climate!
Once you've selected suitable varieties for your climate zone, use your first and last frost dates to figure out the best time to start your seeds or prep your garden. If your last frost happens in early March, that means you can turn over the soil and safely set out your plants after that date. If your first frost happens in mid-November, that will give you an idea of when to bring your plants inside or how long you can expect to harvest tomatoes.
Frost dates also help you determine a reasonable timeline for seed starting. You may want to start your seeds indoors a month before the last frost so they're ready to go in the ground when temperatures warm up, allowing you to take advantage of the full growing season.
A Note About Microclimates
Many areas of the country have their own microclimates that differ from the rest of the region. These microclimates may extend for only a few miles or encompass entire towns, and may exist only certain times of the year or all year long.
An example is Coastal Los Angeles, which falls into USDA Climate Zone 10b. While the weather is generally warm and mild, early summer can bring chilly temperatures and thick fog every morning — a sharp contrast to the hot and dry climate of Downtown Los Angeles, just 25 miles away and also designated as Zone 10b.
By being aware of your microclimate, you can better adapt your prepping and planting for these unique seasonal shifts.
Expert Tip: Pay attention to the details on your seed packets and plant markers. All the information you need to know (when to plant, what type of soil is ideal, how much sun to provide, how much spacing is needed) can be found on the back of those packets and on the plastic tags that come with your plants.