When to Plant Your Wildflower Garden
Plant In Spring, Summer or Fall
All three seasons are wildflower planting times, depending on your region, your weather, and the way you want to approach establishing your meadow. No matter when or where you plant, site preparation is roughly the same. But the first consideration is not the season; it's your climate...
Planting In Mild-winter Areas
If you're planting in a warm place such as California, Florida or southern Texas, with minimal or no winter frost, you can plant almost anytime, except during your hottest season. Best time is just before your rainiest season begins, and when you know the weather will not be too hot for young seedlings. In Florida, fall is best. In California, most wildflowers are planted during the winter to take advantage of California's greening in early spring.
Planting In Areas With Killing Frost
If you have definite killing frost in winter, things are different. In these areas (most of the country) spring and fall are both fine for planting, and each has its advantages.
Fall and spring planting can be equally successful with wildflowers, and each season has its devoted fans for several reasons.
Many people like to say "Nature plants wildflowers in the fall." and that is basically true. All season long, flowers in the wild are blooming, then "going to seed", which means dropping their seeds to propagate their individual species. For example, a very successful species such as Black-eyed Susan blooms in midsummer, and then drops a large number of seeds from each dying flower in late summer. If weather cooperates, these seeds may sprout before winter. If it is dry and hostile for the seeds, they will simply lay there through the winter and sprout in spring.
Fall Planting Advantage: Earlier bloom.
One clear advantage of fall planting, particularly in cold areas, is that it gives you bloom earlier than spring-planted seed. For example, if you plant a mixture in, say October, you will see growth and bloom about 2-4 weeks earlier the following spring than if you had waited to plant your seed in May. In this respect, wildflower seed performs like grass seed, everyone knows a lawn seeded in fall is usually better established in spring than one seeded in spring.
Your site may determine the time of year you plant. If it is a flat site, you can plant any time you like. If it's at all steeply sloped, you should probably choose spring. This is because fall-planted seed is subject to "washouts", since it has to lie there all through late fall and winter, while spring-planted seed has only to wait until it sprouts. The dangers to fall planting on a slope are obvious.
If you decide to plant in fall, wait until after killing frost. The timing is roughly the same as when tulip bulbs are planted late enough to be sure your seeds will not sprout before winter. The point is to wait until the soil is so chilled that seed cannot sprout, but stays dormant until warming soil and moisture trigger germination in spring.
A great advantage of fall planting is that the weather in fall is usually more predictable than spring. Chances are that in fall you won't be delayed by rains or be locked to a tight time period when your seed must go in. Simply choose your site, prepare your ground and sow your seed before the ground freezes. There's definitely less time pressure on the gardener in fall than in spring.
One disadvantage of fall planting is that you have no idea how much weed seed may be in the soil in your cleared area. However, with fall planting, your flower seed at least has a level playing field with any weed seed that's there. In spring, the weed seeds have some advantage, since they've been there through the winter, all ready to sprout.
Most wildflower meadows are installed in spring, simply because that is when most gardening happens. To plant in spring, timing is important. The earliest possible time is about one week before you'd put out tomato seedlings in your area. In other words, as the seed packets have always said, "when danger of frost is past." But there are other important considerations.
If you're like most meadow gardeners, once you clear your ground by tilling or any other method, you'll want to sow your seed immediately thereafter - if possible on the same day, surely the one after. You can't till the area one weekend and seed the next. Here's the reason. The minute you open the ground, you turn up weed seeds that are in all soil. If you wait before putting in your flower seed, those weed seeds have an important "jump" on the flowers, and they may become quickly dominant over the flower seed as your meadow area grows. By putting the flower seed in quickly, you at least give your flowers a "level playing field" with the grasses and weeds that are sure to grow up with them. Remember when you created a vegetable garden by clearing an area? Weeds popped up quickly, and you immediately pulled them. In this case, no one is going to pull the seedlings that appear after your seeding, at least for awhile. Some of those seedlings are going to be weeds you didn't plant. Don't be foolish enough to think some weeds aren't going to be there; they are.
Spring Planting Advantage: A chance to remove the weeds.
If you're willing to do a little more work and exercise some patience, there is a way to eradicate or at least greatly reduce your weed population before you sow your flower seed. This is one of the big advantages of spring planting over fall.
The idea is to clear the ground, do not sow seed, but instead begin immediately to encourage weed growth as quickly as you can. This means watering if it's dry, and watching closely. After about two weeks, you'll see green seedlings popping up, and you'll know at least the early germinating seed population of your soil. Wait as long as you can (this usually depends on weather and how early you got started). Once you have a good idea of what you're dealing with, you're ready to kill those young weeds and spread your flower seed.
There are several ways to proceed. Many use a herbicide like Round-Up®. Others have been known to lay wet newspaper on the weeds to smother them, but this is not surefire and takes longer. At this point, you must resist heavy raking or tilling again, because if you do, you'll turn up fresh weed seeds which will begin their sprouting process, starting the whole cycle over again. In other words, at this point, you must kill the weed seedlings you see, but NOT disturb the soil again.
Once your soil is clear, sow your wildflower seed and it will grow in what is probably the most weed-free situation possible. Nothing is perfect, and of course, over time, weeds and grasses will invade. But this method gives your flower meadow the best possible start. Obviously, there are several disadvantages. First, it takes time. Second, it usually requires more watering once your flowers sprout, since you're farther along into the season, and spring moisture has subsided. Thirdly, bloom is delayed, compared to when it would have begun if you had seeded when you first cleared the ground. But if you're serious about installing the best ever meadow, all this is worth it.
It's perfectly acceptable to plant wildflower seed in most all areas during summer, except those places that experience temperatures that stay in the eighties or higher. Many flower seeds simply will not germinate at high temperatures. However, in many places, variable weather and cooler nights make early summer fine for planting. The later it is, the more watering you'll probably have to do.
Certain flowers and certain seasons:
Another consideration is the flower seed you are planting. For example, perennials can really be planted at any time of year. They just may not germinate or bloom exactly when you'd like. Most of them have to go through a winter before they bloom, so if you plant perennial seed in spring or summer, do not expect bloom that year, only leaf and root growth. Annuals, of course, grow and bloom quickly and then die with their first frost. This means if you plant annuals in midsummer, even if your weather cooperates, you won't have much bloom, if any, before frost gets them. If you're planting a mix of annuals and perennials (like most), fall, spring or early summer planting will bring annual bloom the first year, and then heavy perennial bloom plus some reseeded annual bloom the second and following years.
Another consideration about annuals: If you plant in fall in cold-winter areas, you may lose the more tender species to late spring frosts after they germinate. Cosmos is one species that is susceptible to spring-kill, but favorites like red poppy and cornflower are tough "half-hardy annuals", and aren't fazed by a few spring frosts.
- Intro - What is a Wildflower Garden?
- When to Plant Your Wildflower Garden
- Where to Plant Your Wildflower Garden
- How to Seed Your Wildflower Garden
- Maintaining Your Wildflower Garden
Ray Allen 11/18/02; updated 10/18/03, 2/18/04, 9/19/04, 4/15/05