Potting soil is hugely important for healthy plants. You could do everything else right, but if you accidentally use regular topsoil rather than potting soil for houseplants, the plant could quickly wither and die. A lot of people know there’s a difference between topsoil and potting soil but are less sure about what the difference is and what it means for their houseplant care. Learn about the different potting mixes and how to choose the best soil for houseplants.
Why Potting Soil is Important for Houseplants
The growing medium provides plants with nutrients, access to those nutrients, and physical support. With a rigid container doing much of the heavy lifting, potting soil doesn’t need to provide as much physical support as topsoil. If you scoop up a handful of topsoil, you’ll notice it’s much heavier than a similar handful of potting soil. Nevertheless, even highly aerated potting soil still provides plenty of physical support between the root system and containers.
Houseplants need the same basic nutrients as other plants: nitrogen (N), phosphorus (P) and potassium (K). It’s providing houseplants access to these nutrients that makes the difference in choosing different types of potting soil and growing mediums. This includes helping to manage the soil’s moisture, aeration, and pH level.
Different Types of Potting Soil for Houseplants
There are a handful of different types of potting soil for houseplants. Many plants can tolerate or even thrive in multiple kinds of potting soil, but there’s usually a best choice for that type of plant. Moreover, there are some plants that require unique growing mediums and have little chance of survival with normal potting soil.
Best Soil for Succulents: Cactuses and other succulents prefer drier potting soil that imitates the natural conditions of these drought-resistant plants. This is done by adding sand, perlite or other aerating agents. This special type of soil for houseplants allows you to use a good amount of water to get every part of the pot wet while minimizing the risk of root rot. Succulents aren’t the only types of plants that can benefit from fast-draining soil. Citrus trees and shrubs grown in containers often do best with this type of special soil mix, for example. It’s also true that there are more succulent houseplants than most people realize. Many types of indoor palms are succulents that benefit from fast-draining soil. Learn more about the special soil you need for succulents.
Acidic Potting Soil Mixes: Some acidic potting soil mixes are specially formulated for certain popular types of houseplants. Miracle-Gro has a slightly acidic, highly porous potting soil that’s marketed for African violets. What makes this soil different is a higher concentration of peat moss. You can also make existing potting soil more acidic by adding peat moss. Peat moss is present in most potting soils and works like a sponge by absorbing and then slowly releasing water into the rest of the soil. It is also acidic. More than just African violets, there are many houseplants that prefer acidic soil. More so than just plants that naturally like acidic soil, you might use slightly acidic soil or periodically add peat moss to counteract hard, alkaline tap water.
Potting Mixes with No Soil: You can find an especially coarse potting mix made of bark, perlite and peat moss for the unique care needs of epiphyte plants. These are plants that grow on other plants. Epiphyte orchids and air plants are the most common type for houseplants. Bird’s Nest Fern is another one. There are many theories and plant care practices when it comes to this type of symbiotic houseplant. One thing they have in common is they are especially vulnerable to root rot when potted in soil. The combination or bark, perlite, and peat moss provides the type of support and slow release moisture these plants need.
Best Specialty Potting Soil for Houseplants: One of the newer products out there is moisture control potting soil. Even more than ordinary potting soil, this mix absorbs and then slowly releases water back into the soil. It makes a lot of sense especially for people who want easy-care houseplants, but we’ve heard mixed reviews about this soil and its tendency to clump together as part of its moisture control mechanism. There are also countless potting soil products out there from local gardening sources and houseplant enthusiasts. You can also make your own potting soil. These custom potting mixes may be trying to optimize performance for particular types of houseplants, or they may be compost and organic potting soil for houseplants.
Growing Houseplants in Water: Some houseplants do better with a potting mix that doesn’t use any soil at all. Some houseplants don’t even need bark, peat moss or perlite, either. Some houseplants can be grown in water with some type of gravel or other physical support. Then simply fill the pot, jar or other container most of the way with water and water-soluble fertilizer. You can also add some activated charcoal to help keep the water clean.