When is it safe to plant in spring?

How to avoid frostbite for your flowers and heartbreak for your garden

If you’ve ever stood in a garden center aisle staring at pansies, debating whether to commit, or if you've ever planted too early only to have your tulips iced out three days later, this one’s for you.

Spring planting is a seasonal ritual, but the timing isn’t one-size-fits-all. While some parts of the country are already digging in the dirt by March, others are still scraping frost off their windshields into May. So when is it actually safe to plant flowers and vegetables outdoors in spring?

Let’s break it down.

The average last frost date is the key

The average last frost date is the single most important factor to guide your spring planting schedule. It refers to the approximate date when your area typically sees its final spring frost, based on decades of historical weather data.

Planting before this date is basically gambling with Mother Nature. Some years, you’ll win. Others… not so much.

Here’s what that looks like by region:

Region	Typical Last Frost Date
Southern US (e.g., Florida, Texas, southern Georgia)	Mid March to early April
Central US & Midwest (e.g., St. Louis, Peoria, Kansas City)	Mid to late April
Northern US & higher elevations (e.g., Minneapolis, upstate NY, Rockies)	Early to mid May
Far North (e.g., northern Wisconsin, Montana)	Mid May or even later

Pro tip: You can find your local last frost date using the USDA’s Plant Hardiness Zone Map or trusted local extension services.

Why is frost such a big deal?

Frost may look pretty on a windshield, but it’s brutal for young plants. A spring frost can:

Damage or kill tender flowers and veggies
Shock root systems, slowing growth or stunting development
Wipe out your entire early planting effort in just one chilly night

Even a dip into the mid-30s can be enough to damage certain plants, especially if it's prolonged or paired with wind.

Why do people say to wait until Mother's Day?

In many parts of the U.S., especially the Midwest and Northeast, Mother’s Day (the second Sunday in May) has become a trusted guide for when it’s safe to plant. While not scientifically precise, it usually aligns closely with the average last frost and is easy for people to remember.

It’s not a guarantee (especially in colder zones), but it’s a good rule of thumb for planting tender flowers and warm-season vegetables.

Other things to consider before planting

Even if the frost risk has passed, don’t rush into the garden without checking a few other key things:

1. Soil temperature matters

Cool soil can stunt or shock plants—even if the air feels mild. Most vegetables and flowers prefer soil temps above 50–60°F. You can buy an inexpensive soil thermometer to check.

2. Nighttime lows can sneak up

Watch for dips below 40°F, especially in valleys or open rural areas. Some early plants (like pansies or spinach) can tolerate it, but tomatoes, petunias, and peppers? Not so much.

3. Hardy vs. tender plants

Some plants can handle chilly nights and even light frost:

Cold-hardy: Pansies, kale, lettuce, snapdragons, peas
Tender: Tomatoes, peppers, impatiens, basil, marigolds

Planting cold-hardy varieties earlier can give your garden a head start while you wait to plant the rest.

Want to test your luck?

If you really want to plant early, be prepared with:

Frost cloths or plant covers
Portable greenhouses or cloches
A flexible mindset—because weather is gonna do what weather does

Bottom line

Planting in spring is part science, part art, and part trusting your gut (and your local forecast). But in most areas, the safest time to plant is a few weeks after your average last frost date—or for many gardeners, right around Mother’s Day.

If you're not sure, wait a few extra days. Your plants will thank you.

And hey, if you're a weather nerd like us, tracking soil temps and frost risk makes spring gardening feel like a full-on science experiment. (The kind where you get flowers and tomatoes as a reward.)

And don’t forget to tag us in your planting photos on social media, especially if you're testing the limits of Zone 5 patience.