Why Is My Venus Flytrap Turning Black?

Observing a Venus flytrap’s leaves turn black can be concerning. This blackening can signify a natural part of the plant’s lifecycle or indicate an underlying issue with its care. This guide will help you determine the reason for the change and what actions to take.

Normal Blackening in a Venus Flytrap’s Lifecycle

Each trap on a Venus flytrap is a modified leaf with a limited lifespan. A single trap can open and close several times to capture insects before its life cycle ends. After catching between one and four meals, or after about three months, the trap will naturally wither and turn black.

As older leaves and traps die, the plant redirects its energy toward new growth. You will see fresh, green traps emerging from the center of the plant, known as the rhizome, while the outermost, older leaves turn black. As long as new growth is replacing the dying leaves, there is no need for concern.

A significant amount of blackening occurs as the plant prepares for its winter dormancy. Triggered by shorter daylight hours and cooler temperatures in autumn, the Venus flytrap will slow its growth and many of its existing traps will die back. This resting period is a necessary part of its health, allowing it to conserve energy for the next growing season.

Unhealthy Blackening and Its Causes

If the blackening is not part of the plant’s natural cycle, it may be caused by one of the following care issues:

• Improper Water: Tap water, bottled water, and even filtered water contain dissolved minerals and salts. These substances accumulate in the soil and cause a chemical burn that leads to black leaves. It is best to use only distilled water, rainwater, or water purified through reverse osmosis.
• Root Rot: Venus flytraps require moist soil, but consistently waterlogged conditions from poor drainage or excessive watering can suffocate the roots and cause them to decay. When root rot sets in, leaves turn black, often starting from the rhizome and moving upwards.
• Incorrect Feeding: The plant should never be given fertilizer or inappropriate food like meat, as these cause nutrient burn that will kill the trap. Overfeeding by providing insects to every trap can also exhaust the plant. A trap may also die if it catches prey that is too large, preventing it from sealing properly.
• Sudden Light Changes: While Venus flytraps need plenty of direct sunlight, moving a plant from a low-light environment directly into intense sun can scorch its leaves. This sunburn causes black patches to develop. Acclimate the plant gradually to brighter conditions to prevent this.

What to Do When Your Plant Turns Black

When you notice black leaves on your Venus flytrap, it is a good practice to trim them away. This helps prevent the growth of mold on the decaying tissue and improves the plant’s appearance. Use small, clean scissors to snip the leaf off near its base, being careful not to damage new growth. Wait until the entire leaf, including the stem, has turned black, as any green parts are still capable of photosynthesis.

Gently inspect the plant’s rhizome, the bulb-like structure at the base where leaves emerge. A healthy rhizome should be firm and white or pale green. If you press it and find that it is soft, brown, or mushy, this is a strong indication of advanced root rot, and the plant may be difficult to save.

If you suspect root rot is the cause, you may need to perform an emergency repotting. Carefully remove the plant from its pot and rinse the soil from its roots. Using clean scissors, trim away any roots and leaves that are black or soft. Repot the Venus flytrap in a fresh mixture of one part peat moss to one part perlite, ensuring the new pot has good drainage.