A clumping plant forms a mound or thicket, growing outward from the center and maintaining a compact shape. Clumping plants encompass many varieties, from tall bamboos down to small hostas. In your garden, you can train some plants
A clumping plant forms a mound or thicket, growing outward from the center and maintaining a compact shape. Clumping plants encompass many varieties, from tall bamboos down to small hostas. In your garden, you can train some plants to maintain a compact shape if they don't do so naturally.
The most common plants described as clumping are many varieties of bamboo. This quality distinguishes them from their cousins, the running bamboos, which send out new shoots in all directions from underground rhizomes, quickly becoming invasive. Clumping varieties range from small shrublike bamboos to tall, treelike forms. Smaller bamboo varieties make attractive privacy hedges if planted four to six feet apart. Clumps of treelike bamboo can be kept tidy by periodically removing older canes so the new ones have more room to grow. Clumping bamboos do best in warm climates such as U.S. Department of Agriculture plant hardiness zones 8 to 11, but some varieties are hardy from USDA zones 5 to 9.
Waving ornamental grasses, which come in a variety of colors, are an attractive landscape feature for borders or accent planting. Most are perennials, although some annual varieties exist. Perennial clumps die back in fall in cool climates, when they should be cut back to the ground. They will regrow in spring. You can find ornamental grasses for most climates. They grow either in a compact clump, increasing in diameter slowly, or send out runners from underground rhizomes, similar to bamboo. These grass varieties must be controlled or they may become invasive.
Many common garden plants are naturally clumping, including sun-loving perennials such as daylilies (Hemerocallis), potentilla (Potentilla spp.) and rudbeckia (Rudbeckia spp.). Shade-tolerant plants such as hostas (Hosta spp.) and bromeliads also form clumps. These perennials are all hardy in USDA zones 8 and 9. Keep clumping plants healthy by regularly dividing them.
Division of Clumping Plants
Clumping plants are easy to propagate by division. All you need is a sharp spade or knife to divide the clump into two or more pieces to transplant to new areas in the garden or give to friends. This is a healthy care practice for many perennials as some varieties of grasses and hostas tend to die out in the center and division renews the plants for a better appearance. When perennials, such as daylilies, become overcrowded, their inner leaves stay too moist and the plant becomes more susceptible to disease. The best time to divide any clumping plant is when it is dormant, in fall or early spring.
Creating or Maintaining Clumps
Plants that are natural runners, such as some varieties of bamboo and ornamental grasses, can be trained into clump forms with regular maintenance. Running bamboo can be controlled by mowing around it regularly to cut down new shoots, installing a barrier underground to contain the runners, or planting it next to a natural barrier such as a body of water or a road. Ornamental grass runner varieties can be controlled by regular mowing down of new shoots to maintain a clump shape.
- University of Illinois Extension: Ornamental Grasses
- Auburn University: Group 1: Division
- Beautiful Bamboo: Clumpers or Runners?
- USA Gardener: Flowers: Perennials P-Z
- Ohio State University Extension: Growing Hostas
- National Mission on Bamboo Applications: Factoids
- Bamboo Garden: Cold-Hardy Bamboo
- American Daylily and Perennials
- Thinkstock Images/Comstock/Getty Images