Most houseplants do best in potting soil that allows water to drain easily. Stagnant, sticky soil clings to plants and can rot the roots or allow harmful fungal growth. A variety of bagged mixes are available commercially, but you can easily make your own mix at home. Homemade mixes are often better because you control exactly what goes into the mix and in what amount. This is especially useful if you have several different kinds of houseplants--you can create a base mix and add ingredients as necessary for individual kinds of plants.
Things You'll Need
Large mixing bowl or bucket
One small bag of compost
Two quarts of soil from your garden
One 4-qt. bag of perlite
One 4-qt. bag of peat moss
One 4-qt. bag of vermiculite
How to Make Well-Drained Soil For House Plants
Put your garden gloves on and pour dry compost and the garden soil into the mixing container. Break up any clumps and remove anything that looks like a seed, weed or bug.
Pour in the entire bag of perlite and blend this in with the compost and soil. It's best to do this with your hands rather than a stirring tool--you'll be able to mix it up better.
Toss in a little peat moss. Add it to the other ingredients bit by bit just as if you were adding ingredients to make a cake.
Pour in some vermiculite and work it into the mixture. Add a little more until the whole bag is poured into the mixture.
Shake or stir the potting soil mixture well. Divide it into plant pots for re-potting plants.
It’s much easier to mix this if the garden soil you use is dry. If soil is damp, remove it from the garden and spread it out on newspaper in your home to dry overnight before mixing with the other ingredients.
An alternative to using garden soil is to use a cheap bag of all-purpose potting soil. This soil is usually just as good as or better than garden soil. Just add the peat and perlite for aeration.
For cactus plants or succulents, you may wish to add a little sand to this potting mix.
Always wear gloves when handling compost.