What Is Wrong When a Plant Goes Limp?

Water

• Plants need plenty of water to stay healthy. They have a vascular system, similar to the human circulatory system, that allows water to travel from the roots through the stems and to the leaves and blooms. When the system is full of moisture, the stems and leaves stay stiff. When the plant isn't getting enough water, the stems and leaves start to sag and look limp. Overwatering, however, can also be a problem. It starves the roots of necessary oxygen by filling up all the gaps in the soil around the roots, and the plant can't function effectively. This can also make the plant look limp. If the soil feels dry about an inch below the surface, it's likely you need to water. If the top layer is wet or soggy, you're watering too much.

Light

• Plants need the right amount of light to perform photosynthesis, which turns the light into necessary nutrients. When your plants aren't getting sufficient light, they are hungry and often look limp. This is especially a problem in hot weather -- plants that aren't meant for full sun can dehydrate quickly when the temperature heats up. The best defense for this problem is a good offense; determine which plants need full sun, partial sun or shade, and plant them in the correct locations initially. Otherwise, you'll need to dig up plants suffering from the wrong amount of light and relocate them in your garden.

Root-Bound

• When you use containers as part of your outdoor landscaping design, there's a possibility your plants could become root-bound. This happens when the pot is too small for the size of the root ball. Roots are designed to spread out and down to offer support for the plant as well as to find the best nutrients in the soil. Pots that are too small cause the roots to curl around each other and take up too much space in the pot, displacing some of the soil and keeping some root surfaces from touching soil. Without the proper amount of nutrients, your plants can suffer from stunted growth or they could look limp and wilted. Remove root bound plants from their pots and place them in larger pots to help restore them to health.

Pests and Disease

• Pests and disease are sometimes difficult to diagnose until you notice a symptom in your plants such as limp leaves and blooms. Check the leaves, particularly the undersides, for signs of pests. Pests such as aphids and spider mites drink juice from the plant's leaves, depleting it of moisture and nutrients. This eventually causes the leaves to look limp. Several types of fungus, such as fusarium and verticillium, also cause leaves to look limp and eventually wilt. Spraying the leaves with water can help remove pests, although you might need to use an insecticidal soap or miticide to eliminate the problem. Fungicides can help with disease problems, but look for ones specially formulated to fight the fungus you believe has invaded your plant.