This first section provides basic background information about wildflowers allowing gardeners to avoid major mistakes by choosing a strategy before beginning to plant.
There is one indispensable ingredient to the successful cultivation of a wildflower garden: personal experience. Do not be deceived. Often the carefree appearance of a well-designed wildflower garden can belie the hours involved in achieving a natural look. Devoted wildflower gardeners know well the soil that nourishes. They are familiar with local rainfall and temperature variances. They are always keen observers, noting the first seeds to germinate, watching for the identifying green foliage and delighting in the buds that follow.
WHAT IS A WILDFLOWER?
As natural gardening sweeps across the country, myths about growing wildflowers are beginning to flourish. In the past few years, we have received hundreds of letters from people who believe that since wildflowers grow spontaneously in nature, they will flourish without maintenance in gardens where nothing else will grow.
To understand why this myth is false, gardeners need to look back to the history of flower gardening and ask some questions. At one time all flowers were wildflowers. Long ago some of the wild varieties made the transition to domestic gardens and parks. Over the years, selections were made, resulting in the beautiful, large, uniform flowers found in today's seed catalogs. The important question for new wildflower gardeners is, "Why were some flowers chosen through the centuries to be domesticated while others were left to remain wild?" In other words, "What is a wildflower?"
Today's wildflowers are often either those varieties that grow too easily, quickly taking over as uncontrollable weeds or those varieties that are difficult to grow and have resisted efforts over the centuries to be grown outside their natural environment.
While it is impossible to group all wildflowers into these two categories, the exercise begins to point out some of the major problems gardeners face when planting wildflowers for the first time.
WILDFLOWERS CAN BE WEEDS
Gardeners must learn to avoid weedy varieties such as morning glory and yarrow which can overtake yards and lawns as well as flower gardens. Check the labels of out-of-state cans of wildflower seeds promising instant and long-lasting success. Flowers not "weedy" in one area may be noxious in another. One of our local clients paid more than $4,000 over 3 years to remove weedy wildflowers included in an out-of-state mix.
On the other hand, noxious wildflowers in one area may be fine in another. Even though ox-eye daisy seed sales are unlawful in the state of Washington and bachelor's buttons cause problems in northern Idaho, both can be used in wildflower gardens above 6,000 ft. In fact, we now sell a number of naturally aggressive wildflowers including African daisy and California poppy because sub-zero, mountain winters prevent otherwise uncontrollable invasions. Look to local experience for the best information. Noxious weed lists are available from state agriculture departments county cooperative extensions.
Many of the West's most popular, native wildflowers are classified as difficult to domesticate unless helpful "tricks" are learned. For example, lupine seeds can be put in boiling water to coax early germination. Indian paintbrush is a partial parasite to surrounding native plants and may take 18-24 months to germinate. Many other natives need to be cold-treated (stratified) before germination takes place. Seek advice for regional varieties by asking local, experienced gardeners, nurseries and regional seed companies.
A number of good books about wildflower propagation are now available. Collecting, Processing and Germinating Seeds of Wildland Plants by James A. and Cheryl Young is an encyclopedic approach to collecting and germinating seed ranging from tiny, fragile annuals to tall trees.
Another useful manual for us has been Gardening with Native Plants of the Pacific Northwest by Arthur R. Kruckeberg. This marvelous book identifies 250 wild ornamentals in the Pacific Northwest and describes their natural habitat as well as methods of propagation and cultivation.
One of the more useful "tricks" for successful germination of wildflowers is to "stratify" the seeds. The best explanation of stratification came to us in a letter from Jim Borland who works for the Forest Service in Denver, Colorado.
Jim wrote, "Stratification is a term which was in common use at least as far back as the '30's and '40's and was used to describe a process whereby seeds, usually of trees, were placed alternately between layers of moist sand in a wooden container. After this layering process was complete, the entire container was moved to a refrigerated room where temperatures were usually held between 34°F and 41° F. for the duration of the prescribed period for that species, usually between one and three months.
Although the dictionary word 'stratification' means only 'layering', foresters have long used the term to mean the subjection of seed to both cool and moist conditions, even if the seed was not actually layered with sand or peat moss. Today, seed is mixed with a moist medium and held in a variety of containers in refrigerated storage.
Most importantly, the term has nothing to do with freezing and thawing or the temperatures associated with them. Having done a great deal of literature searching and some experimentation of my own, I have yet to find a documented case where freezing and thawing has had any benefit on the germination of seed of any type, including hard or thick seeded types.
If you buy wildflower seeds that need to be stratified, you might try planting them outside in early spring (March or early April) depending on your area. Mountain gardens usually have six or more weeks of spring weather allowing seeds to be exposed to cold temperatures and damp ground without subjecting them to prolonged stressful conditions associated with dry, sub-zero mountain winters. Sawtooth mountain mint and Colorado columbine both germinate exceptionally well using this method. You can stratify artificially if you live in a warmer climate or want to plant during summer months. Place seeds in moist compost, wrap securely in plastic and place in the refrigerator (not the freezer). Leave for at least 4 weeks.
The process in which plants come and go in specific ecological settings is called "succession". An understanding of "succession" helps to explain why randomly scattered wildflower seeds will not create (in one or two seasons) what botanists call "a stable climax community" of flowers. The varieties of plants in any plant community naturally change over the years. The presence of one variety creates the conditions for others to be established. Depending upon the changing conditions in your garden, different flowers will be more successful at establishing themselves at the expense of less-adapted varieties.
The rate of change in a succession is most intense for several years at the beginning of a new cycle when a wildflower garden has first been planted. The successful wildflower gardener manages these natural changes in perennial wildflower gardens by planting additional wildflower seeds and plants as well as deliberately weeding and trimming the very vibrant varieties.
Overly aggressive, weedy varieties dominate early succession and become difficult to remove or control. Where seeds were originally planted, yarrow, black-eyed Susan and most native grasses dominated every three-year-old, wildflower garden we investigated.
Beware! Descriptions about the life habit of wildflowers in mountain gardens can be deceiving. The fact that a gardener has planted "perennial" wildflowers may mean little in producing a perennial garden. For instance, the vibrant orange California poppy is listed in wildflower books as a perennial. In many places in the upper Wood River Valley in Idaho, it is not. Rarely does this beautiful flower return for a second season and hardly ever a third. On the other hand bachelor's buttons, usually listed as an annual, often reseeds itself year after year.
Seek advice from experienced, local gardeners in your area. The wildlfower charts illustrate varieties' life habits and various characteristics at 6,000 ft. in the mountains of central Idaho and other high altitude areas.
Since the early eighties a movement towards water conscious landscaping has gained a considerable following throughout the country. Called Xeriscaping*, this method of landscaping joins together several principles under one umbrella, integrating the ideas of water conservation, landscape design and horticulture to create landscapes and reclamation areas that are more adapted to their surroundings.
Xeriscaping offers city planners an effective tool in their fight to conserve water. Nationwide, over 60 cities in 25 states have passed ordinances requiring that new landscaping projects adhere to a Xeriscape code. Xeriscaping is not difficult to implement, nor is it more costly than normal landscaping. A properly designed Xeriscape needs less maintenance than average landscapes and uses up to 40% less water. The best designs often incorporate edible vegetables, shrubs, and trees as well as plants useful to local birds, small animals and beneficial insects. Xeriscapes vary from site to site but all are guided by five major principles.
Design according to water usage. In a Xeriscape, plants should be grouped according to their need for water: those needing full irrigation, moderate irrigation or low irrigation. Large trees or heavy water users should be watered individually using drip or soaker systems. Whenever possible allow natural variations in exposure, runoff, or light to dictate design. For example, place water-loving plants in a sheltered north side of a house, or in a drainage where water accumulates in the spring or natural runoff occurs after rain.
Select drought tolerant plants. There are a great number of native or naturalized plants that are beautiful and do well in drier conditions. These include many of our most beautiful wildflowers, native shrubs and trees. Grouping these according to water use and exposure often results in designs which mimic nature, leading to very natural and functional landscapes.
Limit sod areas. Kentucky bluegrass, often used for lawns, is one of the most water intensive of all grasses requiring 18 gallons of water per square foot per growing season. Other more drought-tolerant grasses such as the tall fescues, crested wheatgrass or Canadian bluegrass can be used successfully to create lawns or as a ground cover for large areas with far less water demand.
Irrigate efficiently. It is now possible to irrigate many plants using drip or soaker systems that use a fraction of the water of overhead systems which lose as much as 50 percent of the water to evaporation. Monitoring soil moisture so that water is applied only when necessary and watering early before the heat of the day reduce further water loss.
Take care of the soil. All good gardeners know soils high in organic matter hold moisture better than those with low levels. In addition healthy soils promote healthy plants that are more able to withstand drought or disease. Greater water savings can be achieved through use of a mulch such as straw, compost or shredded leaves or any of a number of new paper and biodegradable plastic mulches.
*Xeriscape is a registered trademark of the National Xeriscape Council, Inc.