I like to tell visitors to my garden that I have a lot of weeds in my garden because I'm trying to promote the free seeding of native prairie perennials. That gets me a lot of pats on the back from wild-eyed environmentalists and everybody likes a little praise. It's true, though. I don't like to use preemergents in my garden beds simply because it will also suppress native plants from sprouting wherever they like to pop up. It means a few more weeds and crabgrass, but one pays the price for one's choices. As my garden evolves, I've learned more and more to choose to nurture the surprise native plant treasures that the Flint Hills provides me.
I have two favorites that spread from the surrounding prairie to various parts of my garden. One is the Blue Sage (Salvia azurea) that blooms in August and September in my corner of the prairie. Also called Pitcher Sage after Dr. Zina Pitcher, a early 1800's U.S. Army surgeon and botanist, Blue Sage grows two to five feet tall with the five foot height more common in a cultivated and mulched garden bed. Its roots extend six to eight feet into the deep prairie soils below, so in my garden it never gets or needs supplemental water even in the current +100 August weather. I've found that the plant gets a little bushier, it doesn't sprawl as much, and I can delay the bloom if I trim it back a little bit in late July to about two feet tall. But most important is that heavenly sky blue color so coveted by many gardeners and by this gardener in particular. There are other blue salvias, of course, but in my Zone 5 garden this is the one that sticks. Over ten years I've got six plants now growing in my various beds, at the cost of only recognizing the seedlings when they first begin to grow and leaving them alone. And truly, how better to find the right micro-environment for a specific plant than letting them seed themselves?
My second favorite of the self-seeding prairie natives is the native Asclepias tuberosa, or Butterfly Weed. Popping up here and there in the most barren, arid spots I have, this bright orange native draws in butterflies in July and August like, well, moths to a flame. There are eight current clumps of this perennial in my landscaping and since it has a long taproot and is difficult to transplant, I'm lucky to have it seed itself in areas that it likes. It is well-behaved, never invasive, and keeps to a polite two to three foot height without trimming or coddling. A better perennial for a garden can't be found and I hope it escapes the ravages of the hybridizers so I don't have to push away my native orange variety for some muddled pink or off-white ugly cousin.