Recently someone asked me to identify a plant growing in her garden. The many plants she had turned out to be spiderwort.
Spiderwort is a native plant usually found along the edges of a forest, along roadsides and in moist areas. There are many species of this plant since they have been hybridized. Over the years some were grown commercially for the home garden, but because of their invasive habit I doubt they are a popular plant for sale at garden centers. I checked with two greenhouses and neither of them carries spiderwort because of its invasive habit.
One must be careful growing a spiderwort plant. I have heard some experts say not all are considered invasive, but the species with which I am familiar are definitely invasive and become difficult to control or eradicate.
The most popular species grows between 14 and 24 inches high. The flower has three petals and is usually purple. Each flower lives for only one day — sunrise to sunset — but many flowers appear on the plant. The blooming time is late spring to early summer. The leaves are narrow and bend over. When a stem is broken a sticky substance can be seen and when touched can be stretched resembling a strand from a cobweb, hence the name spiderwort.
Some gardeners have successfully kept their plants under control by physically pulling them out of the ground. Other gardeners are frustrated as they continually see more and more plants appearing.
These plants self-seed prolifically. It is important to remove each spent blossom before it can set seed.
As soon as the leaves decline and spent blossoms have been removed, cut the plant down. Do not mow over these plants as that just encourages more plants to form.
Despite all your efforts to discourage germination of any seeds, you may still find some sprouting. Remove them and carefully weed the area. Non-living mulch such as straw or hay should be spread over the site. It has been my experience when discouraging any kind of weed it is wise to spread several layers of newspapers or a sheet of black plastic first before the mulch.
Some spiderwort plants may pop up in locations such as crevices where mulch cannot be applied. Some folks have successfully eradicated the plants by pouring boiling water on them.
Many years ago someone gave me some spiderwort plants. At the time I wasn’t aware that these were so invasive. They were planted with some common daylilies along a stretch of ground near a stream. Luckily the daylilies and some other natural growth choked out all the spiderwort plants — much to my delight.
June Fuerderer is horticultural chairman of the Old Homestead Garden Club.