In the past few years I've read about and have seen more interest in wildflowers, so I figure it's about time I jump in and add my two cents.
I have watched in despair as some of my friends have created a wildflower bed in their yards, and have ended up with the biggest, ugliest patch of weeds I have ever seen. Why did they get weeds instead of wildflowers?
One, they were armed with a lack of good information, and two, they were led to believe that planting a beautiful bed of wildflowers is so easy that a child could do it. Actually, a child could do it, and with great success. But only if that child were extremely lucky, or had a basic understanding of exactly how to plant a bed of wildflowers and achieve incredible success.
In the next few minutes I intend to arm you with enough good information so you can successfully plant a beautiful bed of wildflowers, and have your neighbors hanging over the fence asking you how ya did it.
First of all, you've got to understand what kind of a neighborhood wildflowers like to live in. They tend to prefer wide open spaces with at least 8 hours of sunshine each day. It's true, they are sun worshipers. They also like the soil to be rich in nutrients, and well drained. They don't like hard packed soil, and they don't like to get their sneakers wet, only for short periods of time.
If you have an area that tends to be wet, wildflowers are not the answer.
Wildflowers can be used for weed control, and with a great deal of success. But you have to give the wildflowers a running start, or the weeds will keep the area "Wildflower Free". Weeds and wildflowers are both sun worshipers, so whoever reaches the top first wins. Neither will grow well without adequate sunlight. If you use this to your advantage you can have a beautiful bed of wildflowers that requires little maintenance.
The secret is proper bed preparation. You must create a bed that is as weed free as possible. You can do this by removing all the vegetation from the area you intend to plant in, and then prepare the soil for planting by tilling or raking to a depth of just one inch or less. Do not disturb the soil any deeper than that, or you will just disturb dormant weed seeds that are just waiting to be brought back to the surface so they can grow. You should consider spraying the existing vegetation with Roundup before you remove it. This will kill all the roots that might still be in the soil.
Keep in mind that you need to spray the weeds or grass with Roundup at least three days before you disturb them. If you feel that the area you have chosen has a significant amount of weed seed near the surface, you might consider letting the soil sit for about six days after you work it, then work it again. Do this over and over, but don't work the soil more than one inch deep. The longer you continue this process the more apt you are to get the bed as weed free as possible.
Most weed seeds germinate rather quickly, so when you bring them to the surface through your cultivation efforts, you are giving them a chance to germinate. But then when you work the soil again in six days, you will actually interrupt the germination process and the seed will be spent. The longer you continue the process, the fewer viable weed seeds you will have to contend with. Of course additional seeds are blowing in all the time, so it's unrealistic to think that you can create a planting bed that is free of weed seed.
The most important aspect of this process is to have your bed as ready as possible, at the ideal time for planting wildflower seeds. The secret of success is to plant the wildflower seeds at the ideal time so they take off growing immediately, and beat the weeds at their own game.
The ideal time? Depends on where you live. If you're in zones one through six, you should plant in the spring. If you're in zones seven through 11, you should probably plant in the fall.
Wildflower seeds like warm soil. They will germinate best with a soil temperature of 68 to 70 degrees F. So if you live in a cooler region, you should wait until later in the spring to plant. There's no point planting when the soil temperature is 45 degrees and have the seeds just lay there while some of the weed seeds germinate. You'd be much better off to continue working the soil as described above until the soil temperature is up to 68 degrees.
I'll say it again, just in case you missed it earlier. Don't work the soil any deeper than one inch.
Now for planting the wildflower seeds.
The best way to plant your wildflower seeds is to distribute them with a small hand held broadcast spreader, or to apply them in a manner that mimics that technique. In order to get the best coverage you should thoroughly mix the seeds with dry sand, vermiculite, or potting soil to increase the volume before you spread them. It's a lot easier to evenly distribute five pounds of granular material over an area than it is 8 ounces.
As you spread the seeds, walk in straight lines from one end of the bed to the other. Then do the same thing from the side of the bed in a crisscross pattern to the first set of footsteps you made. This will give you thorough and even distribution. This is why you should mix the seeds with some sort of filler material before you start, so you have plenty of volume to work with, and will be able to cover the area completely and evenly.
I urge you to visit www.wildseedfarms.com and ask for a catalog, or call their toll free number. 1-800-848-0078. This company publishes one of the most complete and informative catalogs I've ever seen. They have a color photo of each variety, along with a good description. They even tell you what percentage of seeds you can expect to germinate, and this varies from variety to variety, so they list this information for each variety.
They also tell you how long each variety takes to germinate, and what the ideal soil temperature is. They tell you how many seeds are in each pack, how many seeds in a pound, and how much seed you need to cover a given area. Wildflower seeds have germination periods of 6 to 28 days, so you have to keep this in mind as you plan your garden. If you select a variety that has a 28 day germination period, you should select a second variety with a much quicker germination period and mix them together before sowing.
If you were to sow only seeds with a 28 day germination period, the weeds would get a jump on the wildflowers, and you would likely end up with a weed garden. When you mix seeds with different germination periods, the faster germinating seeds will come up very quickly, and act as a nurse crop for the seeds that need more time, keeping the weeds and birds at bay until all the seeds can germinate.
Good luck with your wildflower garden! Have fun, and enjoy.