What Time of Year Do Venus Fly Traps Open Up?

Even if you haven't grown a Venus flytrap (Dionaea muscipula), you probably know someone who has. Its carnivorous activities throughout the active growing season fascinate young and old. Often mistakenly viewed as an exotic novelty, this North American native naturally occurs only in a small area of the North and South Carolina coastal plain. Understanding this perennial's growth cycle and the needs of those insect-eating traps can spawn years of enjoyment.

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Native Venus flytraps reside in a small slice of the Carolinas.

About Those Traps

A single, hinged leaf folded along a center vein forms each of the Venus flytrap's jaws. The plant relies only on its snapping mechanism, no sticky surfaces, to capture its meals. As sweet-smelling nectar draws insects in and trigger hairs along the leaf surface cause the trap to shut. When an insect touches more than one hair in close succession, the trap snaps closed in just one-tenth second. Rather than flies, crawling creatures such as ants, millipedes and beetles often wander into the open jaws and meet their end. In a process that takes several days, digestive enzymes secreted inside the sealed trap liquefy prey and the plant absorbs the meal. Once finished, the leaf opens again.

Annual Growth Cycle

Hardy in U.S. Department of Agriculture plant hardiness zone 8 through 11, Venus flytraps live 20 years or longer. During the natural growing season -- spring through fall -- traps are open and catching prey. Individual leaves trap several meals, then wither, drop and are replaced by new growth. For long life, the plant must have a dormant winter season during which traps close. A fully dormant Venus flytrap, mulched for winter protection, can survive freezing temperatures and snow. Grown from rhizomes or seed, the plant requires insect pollinators. Its white, late-spring flowers sit on stalks that keep bees, flies and wasps safe from open traps below.

Native Habitat

Many Venus flytraps are commercially grown outside the United States. The plant's only native habitat is a 100-mile radius of wet, pine savanna where North and South Carolina meet along the Atlantic coast. Where sandy, sun-lit, nutrient-poor soils abruptly shift from wet to dry, about 100 colonies are estimated to still exist. In this boggy, highly acidic environment, many plant nutrients become unavailable in soil. It's believed the plant's traps adapted because of this inability to draw nutrients from the soil. Instead, trapped insects provide the nitrogen and phosphorus needed for plant growth.

Culture and Care

The key to Venus flytrap's health is to replicate its natural home. Give them full sun, high humidity and poor, acidic soil. Never fertilize your flytrap; the meals caught by its open traps provide its needs. Wherever and whenever possible, grow the plant outside. It needs more sunlight than a windowsill provides, and natural light keeps dormancy on schedule. For best results in containers, plant in pure sphagnum moss or peat. Let them sit in water, wet but not soggy, with the water level always at least 2 inches below the surface. Avoid anything alkaline, including water. Outside, those open traps catch plenty of prey on their own. Inside, you'll need to provide live insects and spiders.