Spiderwort is a perennial plant that grows 2 to 4 feet tall and wide. The flowers are usually purple-blue but can also be pink, white or red depending on the cultivar. These flowers are sometimes called "dayflower" because the blooms only last one day. However, the plant produces many blooms throughout the growing season and usually has at least three opening each day. Spiderwort makes an interesting border plant in USDA planting zones 4 through 9, but you can plant it in containers and bring it inside for the winter in any zone.
Keep an area 2 feet in all directions around the plant clear of weeds and lawn grass. This can be done by spreading a 3-inch layer of mulch around the plant or by hand-picking weeds. If using mulch, keep it at least 3 inches from the main stem of the plant.
Water the soil to keep it evenly moist. Some cultivars of spiderwort like continuously moist soil. Others prefer it dryer. Read the directions that came with your plant or watch for the leaves wilting. If they start to wilt, water the soil, and they should come right back.
Apply a general-purpose fertilizer to the soil each spring. Do not allow the fertilizer to touch the main stem, and water immediately after spreading to leach it into the soil. Follow the manufacturer's directions as to how much fertilizer to apply to the soil.
Spread a 2-inch layer of compost on the soil over the root area. Water the compost to leach it into the soil over time. Spiderwort normally dies down in the heat of the summer, so this is a good time to enrich the soil. The plant sprouts back up in early fall.
Lift the plant's clumps out of the soil every 3 or 4 years to divide them. Using a garden fork, lift 3 inches past where you think the roots are, so as not to damage them. Divide the clump into sections with a sharp knife and replant them right away so they don't dry out.