Getting Red Hot in the Green of Spring
Warm temperatures and rain have kick-started the growth of many of our wonderful flowering trees and shrubs. I love seeing the soft green starting to take over the landscape. However, there are a couple of plants that I hate seeing in the spring. These plants get my blood boiling because of the larger implications.
Water hemlock (Conium maculatum) is one of these plants. It greens up faster than many of our other ornamentals, and where there is one, there are many more nearby. The reason it greens up so fast in the spring is that it is a biennial plant. Biennial plants have a two-year life cycle, meaning that in the first year, they produce only vegetative growth, meaning lots of leaves and a developed root system. In year two, they push out their flowers and produce seeds. With stored energy in their roots, the right conditions can cause them to push out their flowers fairly quickly. Our Kansas springs are also not always mild. Some years, we can see 90°F days in April, which really speeds up the development of these weedy flowers.
Yes, they are poisonous. Yes, they look like wild carrots, and if you are not an expert in telling the two apart, you shouldn’t forage for wild carrot. But the reason I despise them with a burning passion is due to their seeds. I love being outdoors. I will even take a chance to get off the beaten path to get a closer look at something special. And I never fail to get these seeds stuck to my shoes, socks, or other pieces of clothing. Getting these stuck in my hair is absolutely the worst. Their seeds have tiny hooks that grip onto hair or other fibers, and this is why we see them spread so far and wide. If you are a nature explorer like me, when these seeds inevitably stick to your clothes, clean them off and throw them in the trash. Don’t pull them off and instinctively drop them on the ground, or they might grow there.
Another problematic plant, very noticeable in spring, is the Bradford pear tree (Pyrus calleryana). The pretty white flowers, even though they smell like dirty socks, are very attractive to the average person after a long, brown, and grey winter. But to me, it looks like smelly, woody weeds. This was widely recommended for use in suburban housing developments. The reason for this? It grows well here in Kansas. Perhaps it grows a little too well. The ones sold on the market were supposed to be sterile, meaning the seeds in the fruits weren’t supposed to germinate and grow. However, they escaped cultivation and are wreaking havoc on vacant lots, pastures, and fence lines.
If it weren’t for the Department of Transportation's mowing efforts, the sides of the highways would be Callery pear forests. These trees can't be controlled by conventional methods either. Burning, which is effective for eastern red cedar, is not effective in controlling Bradford pear. Their root system can develop rapidly and often regrow after a prescribed burn. A combination of herbicides and burning is the most effective way to eliminate these destructive plants. If you have one in your yard, there have been many past buyback programs available that will help pay for a replacement tree. On the Missouri side, the Missouri Department of Conservation is currently engaged in this buyback program. Replacement trees will not be the same size as the one you cut down in your yard, but they can become a long-lived and more environmentally friendly option.
The good news is that gardeners and homeowners have better options. Removing invasive plants and replacing them with well-adapted trees, shrubs, and perennials can help restore balance while still providing beauty in the landscape. If you’re not sure what to plant instead, Johnson County K-State Extension can help. Visit our website or contact the Garden Hotline for recommendations on suitable and non-invasive replacements that will thrive in our region.
by Markis Hill, Horticulture Turf and Ornamentals, 2026