Weeds and wildflowers: Which ones work?

Posted by Jessie Jacobson on Aug 11th 2017

Ever see a flower in the roadside ditch that is just so pretty and wish you could plant it in your own garden? What about that irritating plant that seems to be taking over your lawn and is impossible to get rid of? Is there any use for it? Both can be described as weeds and wildflowers. Some of these plants are natives, are adept at growing in our climate and soil, and they don’t tame easily but are still desirable (milkweed, for example). Others are quite stunning but are invasive and harmful to our local ecology. If you’ve ever wanted or needed to ID a rogue plant, there are great resources out there to help. Here’s some info to start, and a couple must-have reference materials for your garden library to help you become an expert on all things weeds and wildflowers (or at least seem like one!). Field Thistle: This naughty, invasive, noxious weed is a bee magnet, but it spreads like wildfire, is hard to kill due, in part, to its extremely long tap root, and is no fun to be around (it’s quite mean and pokey). Canada Goldenrod: Though this is a ready re-seeder and spreads like crazy, it is a native and, despite its reputation, it does not cause hay fever. As a late-season bloomer, it’s great for pollinator food as other plants begin to fade. Plantain: Low-growing, flat leaves with spike-like flowers, this is definitely weed, and one that loves to root in lawns. But if you do find it in your yard (and you’ve not yet treated it), feel free to toss it into your next salad or saute it. Yup, it’s edible. It can also be chewed and applied to a cut, where it will dry and act as a bandage. That’s one useful weed! Purslane: Also definitely a weed, and quite prolific – you can eat this one, too! Sedum-like leaves and stems and a low-growing, spreading habit make this a tempting one to leave alone as it acts as a nice ground cover. It’s aggressive, though, so pull it out, wash it up, and pop it in your mouth! It has a higher concentration of omega 3 fatty acids and antioxidants than any other leafy green! Purple Loosestrife: This one is beautiful and very, very bad. The tall, purple flowers grow in wet soil conditions like ditches and marshes. There is no doubt it is pretty, but it’s not native and it is invasive. It’s taking over spaces where native plants should grow but are unable to compete, and it’s not suitable for native wildlife to nest in or around. Attractive or not, this plant should be eradicated wherever possible. Swamp milkweed: Up to 5 feet tall, it grows in a clump. Although it does well in swamps and damp soils, it also grows happily in regular garden conditions with average watering. Pink or white flowers, long and pointed medium-sized leaves. Full sun. Common milkweed: Up to 3 feet tall. Wide, more rounded leaves, with purplish, mauve globe-shaped flowers that smell somewhat like lilac. Easily grown in average to dry, poor soils, this one likes full sun but can tolerate some shade. Whorled milkweed: Up to 2 feet tall, with very skinny leaves and white flowers. Grow in average to dry soil conditions. This one spreads by rhizomes so it can be aggressive. Great for naturalizing. Full to part sun. Butterfly weed: Low-growing, mounding habit with orange blooms and thin leaves. This one loves the sun and is drought-tolerant once established. Up to 2 1/2 feet tall and wide, it is great for the front of the garden and is better-behaved than the other milkweeds. All milkweed will produce seed heads that, once mature, crack open to allow seeds to float on the wind, settle in, and get growing. Monarch caterpillars need the leaves for food, and the flowers are good for pollinators, but the seed heads aren't necessary except for reseeding. To avoid having milkweed take over your landscape, just remove the seed heads once they form.

Good to know

All weeds and wildflowers tend to have ingenious ways of making sure they just keep living (aggressive self-seeders, deep tap roots, spread by rhizomes, etc.) For those plants you’d like to keep around, just knowing this is half the battle. The other half is staying on top of pulling them out of wherever they shouldn’t be and planting them with other plants that can compete (they can be bullies, sometimes).

Good reads

Wildflowers of Minnesota by Stan Tekiela is an excellent, easy-to-use resource for identifying wildflowers and weeds. It is organized by flower color, making it easy to navigate. Information provided includes color pictures, flower and leaf descriptions, all about how and where the plants grow, and whether or not it’s a native. Another must-have is Weeds of the Northern U.S. and Canada by France Royer and Richard Dickinson. This one includes color pictures throughout, including in several different keys: flower color, seedlings, grasses, and mature plants. This makes it incredibly easy to identify plants across all stages of growth.

Go exploring

Take a walk along the roadside, peek along bike trails, peruse your own lawn – what do you have growing there? Is it useful? Does it just need to go? Oh the things you’ll see when searching for wildflowers and weeds!