Spiderwort: Everything You Need To Know Before Planting

Spiderwort or Tradescantia is a grassy perennial plant native to the Americas. Its colorful, three-petal flowers first emerge in early spring, and range in color from deep blue to bright pink, and less commonly, white. The blooms survive just a single day, opening in the early morning but fading by the heat of the afternoon. The Gardening Channel reassures, however, that the long blooming season stretches into the summer months and ensures plenty of time to enjoy the ephemeral blossoms. This, in addition to its hardiness and ease of care, makes spiderwort a popular plant among gardeners of any skill level.

Spiderwort is named rather literally. According to Missouri Botanical Garden, spiderwort stems release a syrupy fluid when cut. Once it solidifies, the substance becomes smooth and stringy, similar to a spider's web. Before blooming, spiderwort buds resemble small clusters of spiders or their egg sacs hanging on a web. The plant's long, thin, leggy leaves are also reminiscent of a spider's own long, thin legs. Whichever the true source, it's clear that the plant is aptly named. Like it's namesake, spiderwort can adapt and thrive in a wide variety of natural settings. Keep reading below for everything you need to know before adding spiderwort to your own garden.

Spiderwort grows as a wildflower in areas where it is native, but it is also a popular garden bed plant. The Gardening Channel instructs gardeners to plant outdoor seeds in the fall. Before sowing, prepare your garden bed by adding compost to the soil. Once the compost has been mixed to a depth of 8 inches, rake the soil so it's even. Plant seeds about 1/8 inch deep so they are lightly covered, and about 8 to 12 inches apart. It is important that the plants have enough space between them for air to circulate to avoid disease such as powdery mildew.

Gardening Know How explains that spiderwort can be propagated by dividing existing plants, or by stem cuttings. To grow by stem cuttings, plant in the late summer or early fall with enough time for the spiderwort to grow roots before the winter. Propagating by dividing existing spiderwort plants takes a bit more work, but Homestead Gardens breaks it down. Start by digging out the existing plant. Use a sharp knife to cut through the root ball and divide into two to three clumps. Space the divided plants 8 to 12 inches apart, and plant deep enough to cover the entire root structure. Plants can be divided in either the spring or fall, but it should be done every three years or so to avoid overcrowding. 

The Lady Bird Johnson Wildflower Center clarifies that the name spiderwort refers to over 70 known species in the genus Tradescantia, named for John Tradescant who worked as a gardener for King Charles I in the 17th century. Spiderwort is native to the Americas and can be found growing as far north as Canada and as far south as Argentina. All species share similar characteristics, though mature plants range in size from 6 inches to 3 feet tall.

The most commonly grown species is the Virginia Spiderwort (Tradescantia virginiana). According to The Spruce, other varieties were developed by plant breeders to produce specific aesthetic characteristics, such as leaf shape and bloom color. Some other species of spiderwort include:

•  Zigzag Spiderwort (T. subaspera) is named for its zig-zag stem, which can grow up to 3 feet in height.

•  Ohio Spiderwort or Bluejacket (T. ohiensis), is found throughout the Midwest, known for the range of colorful flowers and whitish bloom on the hairless stem.

•  Hairy-stemmed Spiderwort (T. hirsuticaulis), grows primarily in the southern United States and can be recognized by its light blue flowers and leaves covered with small hairs.

•  Tharp's Spiderwort or Dwarf Spiderwort (T. tharpii), is one of the smallest varieties of spiderwort, its bright green leaves growing close to the ground and its stem extending just 6 inches in height.

If you decide to grow spiderwort in a container rather than a garden bed, there are specific ways to maximize growth and ensure your plant stays healthy. According to Garden Beast, spiderwort plants grown in containers will have slightly different characteristics than plants grown in a garden bed, or in the wild. When grown in a container, spiderwort plants produce fewer leaves, darker flowers, and have a longer blooming period. They are also less tolerant of heat than their in-ground counterparts, as they are surrounded by less soil to retain moisture. Thus, potted spiderworts should be placed in shadier spots for best results.

The ideal time to repot your spiderwort is early spring, or late fall. Repotting the plant during the winter months when it is in its dormancy period can shock the plant and risk harming it. Spiderwort do not become root bound, and prefer to live in smaller pots. To repot your spiderwort, select a container that gives the plant an inch or two of room. Gardening Know How recommends planting with a well-draining container mix — either a soilless potting mix or loam-based compost. Gently spread out the roots by hand and remove excess soil. Place new soil in the base of the container before setting the plant inside. Carefully add additional soil between the plant and the container walls until the roots are covered, and the plant rests securely in the pot. Give your plant some water and enjoy its colorful blooms.

Since spiderwort plants grow in USDA zones four through 12, they are susceptible to pests that also thrive in these regional climates. Although the winter keeps insect infestations at bay, the warmer temperatures in spring and summer can put your plant at risk. Aphids are fond of spiderwort leaves, and as they feed on them, they also spread disease. These insects will make your plant unsightly by causing the colorful leaves to shrivel and brown. They don't directly kill the plant but make it more vulnerable to other diseases. Spider mites are another insect to watch for on these grass-like herbs. These creatures feed on the plant just as aphids do, but do directly cause the leaves to die. 

Don't give up too soon if you have either of these pests infesting your plant, for both issues are treatable. Spraying the infested plants with a hose will push the bugs off, but this is usually only a temporary solution. Use neem oil, insecticidal soaps, and horticultural oils according to their manufacturer's instructions to treat and prevent these bugs from returning. You can also apply a weak water and dish soap solution to both sides of your plant leaves, making it difficult for bugs to find perch and feed. Using this solution can be tedious, as you must re-coat the leaves every few days, meaning you should look for specialized products to prevent pest infestations long-term.