Want to grow a wildflower garden? Here are the ins and outs and ecological advantages of planning, planting, and maintenance.
By Wendy Priesnitz
Native plant gardening is a landscape trend that has taken hold. It is one to consider whether you’re one of the new generation of environmentally aware gardeners, or an established green thumb who is looking for something new. In either case, a wildflower garden is a low maintenance (eventually), attractive, and decidedly “green” style of gardening. Increasing numbers of people are researching how to convert their mixed borders – or even whole yards – into wildflower gardens.
However, that might not be as easy as you think. Many gardeners believe you can simply scatter some seeds and wind up with a self-sowing meadow. In truth, starting a wildflower garden is often more work than putting in a perennial border and it is not necessarily self-perpetuating.
Wildflower Garden Challenges
Aside from what may be negative opinions of neighbors or municipal officials about the “messiness,” many gardeners experience frustration growing wildflowers. That is often because they have unrealistic expectations. The beauty of a wildflower display is seasonal. These plants are exquisite during the blooming season. But they may look a little ragged once they have gone to seed.
Also, wildflower gardens (perhaps better thought of as “meadows”) are not for everyone. If your idea of a perfect landscape is one that is predictably clipped and manicured, then wildflower plantings will probably not suit you. If, on the other hand, you find great delight in a glorious display of Nature’s most beautiful flowers, and understand that you are participating in the inevitable cycle of the seasons, then wildflowers are for you. You must also be patient.
Many wildflowers are biennials and perennials, and will not bloom during the first year they are planted. So unless you are prepared for a drab display this summer, you’ll need to include some annuals. Those can be both native species and quick-blooming naturalized ones. If you allow the annuals to form seed heads before mowing, in mild climates many will reseed to bloom during the second year, along with flowers from the biennials and perennials.
Starting Your Wildflower Garden
Choose a site with full to partial sun. It’s important to properly prepare the soil. Remove all existing vegetation. If you’re planting a small area, this can easily be done by hand. For larger areas, mow as low as your lawnmower will allow. Water the area well and then cover the area securely with clear plastic sheeting, leaving it to bake in the sun for up to two months. Future maintenance will be easier if you rid the area of as many weed seeds as possible before planting. Then till the soil to a depth of three inches.
Packaged seed mixes will tell you how large an area they cover. You can plan for four pounds of seed per acre or four ounces per 2,500 square feet. Broadcast evenly throughout the area to be planted. Most wildflower seeds are very small. Mixing some sand in with the seed mixture will make it easier to spread evenly. Rake lightly again after spreading the seed.
If you had the foresight to prepare your wildflower beds last fall, or are replenishing an existing wildflower garden, you can sow your seed very early in the spring when the ground is just starting to thaw.
If live in an area with no snow on the ground or if you’re planting later in the spring, you will need to water during the germination period, unless you live in an area where rainfall is over three inches a month. A light mulching with straw or compost will help retain moisture and keep the birds from eating the seeds. (Don’t use peat for these reasons.)
Maintenance of Your Wildflower Garden
Evaluate your planting at the end of the first growing season. In bare areas or places where perennials did not establish well, over-seed with the original mix. Or try a different one if your expectations were not met. If you had more weeds than wildflowers, start over by eliminating all vegetation and weed seed.
Mow or cut back the entire area to a height of about four inches every fall after flowering is over. Clippings can be left as a mulch or removed according to individual preference. Some clippings should be left to help desired species reseed. Clipping seed heads before they mature helps control species that are becoming too aggressive.
By the third year, your meadow should begin to take on a mature look and the perennials should be well established. To continue to receive good color from annual wildflowers, it may be necessary to re-seed every year.
Weeds and other unwanted species will always be part of a planted wildflower garden, as Nature tries her best to follow natural succession. Of course, the definition of the word “weed” is up for debate, but invasive species should be dealt with quickly and mercilessly. Wildflowers grow densely and weeding should be required less and less as the garden fills in. As you weed, sow seeds of the original mix or annuals in the spaces left bare.
Invasive Species and Your Wildflower Garden
Wildflower gardens are made of native species that have established themselves without assistance from humans. A non-native plant (sometimes known as an “exotic species”), on the other hand, has been introduced by human activity, either intentionally or by accident. Then there are invasive species, which are plants capable of moving aggressively into a habitat and monopolizing resources. In some cases, they are so prolific that they create a biodiversity destroying monoculture. Some of these “over-achieving” plants contribute to the decline of endangered and threatened native species. Additionally, some studies that the fruit produced by invasive plants are, in effect, the “junk food” of the plant world. As such may not be as nutritious to local wildlife, perhaps contributing to their decline.
Different species will be invasive in different areas. But many of our popular garden plants fit the category, including Norway Maple, Burning Bush, Purple Loosestrife, Japanese Honeysuckle, and Multiflora Rose. Since gardeners – botanic gardens and home growers alike – are responsible for about sixty percent of invasive species, environmentally aware gardeners should plant native species only.
Native Plants and Climate Change
Climate change experts are telling us that global warming will result in the disappearance of many of our local and regional plant icons, along with the related tourism, products and ecological communities that depend on them. For instance, maple/beech/birch and spruce/fir forest types are very likely to be completely displaced by more southern forest types by the end of the 21st century in New England and eastern Canada. And a study at the University of Virginia suggests that in twenty-five to thirty-five years, Minnesota’s climate will be similar to today’s climate in Kansas, which is drier and warmer than Minnesota’s. Minnesota’s climate could even become more like current-day Oklahoma, a scenario that would seriously threaten the future of native prairie plants and grasses.
Traditionally, plant conservation strategy has been involved with protecting and managing land. But now, some of the ecosystems that have been protected, such as bogs and northern forests, could be eliminated. That would allow new invasive species to take hold as the climate becomes more favorable to them.
University of Virginia researcher Julie Etterson says that native plants face two problems that affect their long-term survival. One is the fast rate of climate change. The other is that the habitat of native plants is often fragmented to isolated islands between farms and cities, making it difficult for plants to slowly migrate to areas with more favorable conditions.
This means plants will have to rely more on their evolutionary response to changing conditions. And some won’t likely adapt quickly enough. “Climate change is a complex and serious plant conservation issue with a profound impact on plants and ecosystems,” says Gwen Stauffer, Executive Director of the New England Wild Flower Society, America’s oldest plant conservation organization.
Experts around the world are taking notice and planning for the future. The Millennium Seed Bank project, initiated by the Royal Botanic Garden in Kew, in the U.K., is, for instance, collecting and banking seed for ten percent of the native flora in order to create an insurance policy against ecological loss or damage.
Building a garden that works with Nature, not against it, will be a rewarding project that will not only be beautiful to look at but give you the satisfaction that you are preserving our native plants at a time when they’re stressed by development, invasive competitors, and climate change.
Plant Conservation Alliance
Growing & Propagating Wildflowers (The New England Wild Flower Society) by William Cullina (Houghton Mifflin, 2000)
A Gardener’s Encyclopedia of Wildflowers: An Organic Guide to Choosing and Growing over 150 Beautiful Wildflowers by C. Colston Burrell (Rodale Books, 1997)
Native Alternatives to Invasive Plants by C. Colston Burrell (Brooklyn Botanic Garden, 2006)
Grow Wild! Native Plant Gardening in Canada by Lorraine Johnson (Random House of Canada, 1998)
Natural Landscaping: Designing with Native Plant Communities by John Diekelmann and Robert M. Schuster (University of Wisconsin Press, 2003)
Newcomb’s Wildflower Guide by Lawrence Newcomb (Little, Brown and Company, 1989)
Wildflower Field Guide series by Roger Tory Peterson (Houghton Mifflin, various dates)