Carnivorous Plants: Pea Gravel

Understanding Carnivorous Plants

• Carnivorous plants have evolved in conditions where the soil provides very little nutrition, primarily acid bogs. Though they make their own carbohydrates, proteins and other compounds through the process of photosynthesis, like all green plants, carnivorous plants obtain nutrients from the insects that they trap and digest. There are many different types -- sundews, pitcher plants and Venus flytraps among them -- and each have preferences for specific cultural conditions. In general carnivorous plants like sun and a nutrient-poor mix that is kept constantly moist.

Pea Gravel In The Soil Mix

• A typical soil mix for a carnivorous plant contains sphagnum peat moss or long-fibered or live sphagnum moss, sand and perlite. Sphagnum is a nutrient-poor, acid source of organic matter that holds moisture well. Sand contributes density and aeration. Perlite is an expanded volcanic material, very light and white in color, somewhat smaller than pea gravel. Substituting pea gravel for the perlite will give you a heavier mix, useful if the pot is narrow or the plant tall. It also has the advantage of not floating to the top of the soil, as perlite sometimes does, when you water.

Pea Gravel As Mulch

• Pea gravel is an excellent mulch for small plants, helping to conserve moisture in the soil. In warmer areas, the rocks may hold heat and warm the soil more than the plants prefer, especially those native to cool mountain areas. Consult a guide to your specific type of carnivorous plant for recommendations.

Watering Carnivorous Plants In Gravel

• Many carnivorous plants prefer water that is moving through the soil, conditions you might find near a mountain stream, for instance. Daily watering is needed and gardeners sometimes leave ice cubes on the surface of the soil to drip through to the roots. Pea gravel will allow water to flow freely but should be mixed with generous amounts of peat to help hold moisture. Be sure to use distilled, deionized or reverse osmosis purified water without fertilizer since carnivorous plants are sensitive to salts and excess nutrients.