Deep in the darkest hours of winter, our fingers start itching to plant spring flowers. It’s a common malady: There’s a reason spring gardening catalogs are so popular in late January and early February. It’s almost as if Mother Nature programmed us to want to garden at the optimal time to start planting flowers — and she probably did. In most northern regions of the United States, you’ll need to start planting seeds indoors before the end of winter if you want lots of colorful spring flowers. Whether you start early-spring flower seeds indoors or sow them directly in the ground, though, you need to know the best time to start planting and moving your plants outdoors. When is the best time to start planting your spring flower garden? These tips will help you figure it out.
Planning Your Planting — Early-Spring Flowers for Your Garden
One of the most important things you can do to ensure a beautiful garden is probably the most boring: research. Like it or not, some flowers just won’t do well in your climate, at least not without a lot of modification and care. That doesn’t mean you absolutely can't grow daffodils in Arizona or hibiscus in New England. It just means you have to find the right varieties, and invest some time in caring properly for them. If, on the other hand, you prefer to spend more time enjoying spring blooms than caring for them, you should choose plants that grow easily in your region, or flowers that are hardy in any growing zone.
The single most important rule in figuring out when to plant your flowers outdoors is this one: Plant after the danger of frost has passed. Here’s how to determine the earliest time you can plant flowers outdoors in your garden.
Find Your Hardiness Zone
The first step in planning your garden — and figuring out when to start planting it — is knowing your hardiness zone. The USDA Plant Hardiness Zone Map is your best tool for that. The updated version even lets you search for your zone using your zip code, which can come in handy if you live in an area with a microclimate. Most plants and seed packets will tell you the best date for planting indoors and outdoors based on hardiness zone.
Monitor Your Own Garden Conditions
Speaking of microclimates, your yard may just have its own little pocket climate going on. One of our staffers learned this when they transplanted a few irises from their backyard, where they were a single bright spot that bloomed reliably each spring, to a front border, where they bloomed a week earlier and flourished so well that they had to give away half the border each fall. The difference? So much more sun and better soil where the plants weren’t in the perpetual shadow of the house. AcuRite tools can help you monitor the soil and weather conditions in your own microbiome so that you can plant and care for your garden with the most accurate information possible. You can also use AcuRite products to help plan your garden and prepare it for spring planting. Knowing the moisture content, pH level and average sunlight of your gardening spot will help you make the best choices for a gorgeous spring and summer garden.
Should You Start Your Flowers Indoors?
Your next decision is whether to start your flowers indoors or sow them directly in your garden. There are a couple of things to consider when making that decision:
- How long does the growing season last? If you have a short growing season — or springs that go from freezing to midsummer in no time flat — giving your plants a head start indoors will get you from seed to flower with enough time to actually enjoy those blooms.
- How well do the flowers transplant? Some seeds are easier to transplant than others. Here’s a handy list of flowers sorted by whether to start indoors or sow in the ground.
When to Start Seeds Indoors
The general rule for starting seeds indoors is “six weeks before the final frost,” but like most general rules, there are exceptions. Plants that take a long time to germinate, for example, need to be started earlier if you want to get the most bloom time out of them. Here’s a gardener who shares her (very complicated) personalized seed-starting schedule, along with how she determines the best times to start her seeds indoors.
If you prefer things to be a little easier, this is a down-and-dirty two-step indoor seed calculating method:
- Find your first and last frost dates by zip code in the frost-date calculator from “The Old Farmer’s Almanac.”
- Plug your last frost date into the Seed Planting Schedule at Johnny’s Selected Seeds
Is It Time to Plant Outdoors?
Whether you’re starting from seed indoors or sowing directly outdoors, the most important date to know is the last frost date for your region (as we’ve already discussed). If you’re sowing seed directly in the ground, you can safely plant seeds for most plants outdoors after that date. Here’s a basic frost-free chart you can use as a starting point:
Plant Now to Enjoy Later
Strategically plant late bloomers in early spring for late-summer color in your garden. Spring is the perfect time to plant gladiolas and asters, which will bloom in late summer just when the cool-weather lovers start drooping and fading. Other summer bloomers include cosmos — a kid-friendly favorite — Crocosmia, dahlias, and sunflowers, all of which can be planted outdoors after the danger of frost has passed.
Super-Gardener Tips for Early Bloomers
- Want daffodils and crocuses this spring, but didn’t get bulbs in the ground last autumn? Either buy chilled bulbs or chill them yourself. Early-spring bulbs rely on a period of cold to prepare them for spring blooming. You can simulate that by popping your bulbs into a paper bag and sticking them in the refrigerator for six to eight weeks before last frost, then plant them directly in the ground where you want them to grow.
- We particularly like starting showy flowers like impatiens and petunias indoors about eight to 10 weeks before last frost. They like cool temperatures, and giving them an indoor head start means they’re just coming into bloom when the weather hits their blossom sweet spot, ready to plant in beds and baskets.
- Plant spring-blooming bulbs in the fall to get early-spring flowers without the hassle of chilling them.
- Plant a mix of perennials and annuals to enjoy color in your garden all summer long. Some annual flowers are also notorious “volunteers,” self-seeding in garden beds so that you don’t have to work so hard next year.
Feeling ready to get planting? Tag us on Instagram to share your garden’s progress!