It’s just about finished blooming now, but you may have noticed a small/medium-sized tree blooming white in round flower clusters everywhere along our roadsides the past few weeks. These trees are descendants of the Bradford Pear, a cultivated variety of Pyrus calleryana, the Callery Pear, and they are a classic example of what is known as an invasive species.
What is an invasive species? It’s an introduced organism that spreads without any controls, causing harm. Some invasives affect human health. Some create problems for recreation as weeds degrade habitat for hunting, fishing and boating. Many agricultural pests are invasive plants or pathogens. Some invasive plants make areas more fire prone (folks in California know all about this). Invasives are a factor in the extinction of a number of plants and animals. Invasives radically change ecosystems (think of the Chestnut blight or Kudzu). They leave non-invasives little or nothing to eat, and they change species diversity, leading to a loss of biodiversity.
Bradford Pears are great examples of this — they form dense stands and create dense shade, preventing anything else from growing around or under them. They have no environmental controls, nothing eats them and they have few diseases. From a landscaping standpoint, they are a terrible tree! Their flowers smell terrible; they get big, to 50 feet; their branch structure leads to huge branches breaking off or the tree splitting in storms; their shade is so dense you can’t grow anything under them.
There are many great alternatives to Bradfords, though! Try a Serviceberry, a Redbud, a Dogwood, a Hawthorn, or a Fringe tree, or even one of the flowering cherries. All of those are well behaved, most are native, and all are lovely!
Q: Can I do a spring clean-up without harming the environment?
A: Yes! You definitely can. You can have a nice, tidy yard without harming all the critters who depend on you for their homes, without spraying chemicals everywhere, and without getting out all those noisy, polluting yard machines.
When you’re cutting anything back (old perennial stalks, or grasses), just cut it down close to the ground level with your pruners or shears, then lay the stalks down behind the plants or off in a corner where you won’t see them. The butterflies, ladybugs and other good bugs will still emerge since you barely disturbed the plants, and the birds will love all the nesting material you have provided.
Don’t automatically go for the bug spray if you do see bugs — this is important all year round — call your local garden center or take a photo on your phone so a garden professional can try to identify the bug to see if it’s even a problem — most aren’t, and are good food for the birds.