You wouldn't dream of buying all-purpose pet food and expect to feed your finicky feline the same food as your child's pet bunny. Yet, you many believe that bag of all-purpose potting soil will meet the needs of all your plants. To grow healthy, vigorous plants, you must provide the proper growing conditions, and that includes the soil. The type of potting soil your plant needs depends on the species of plant and its preferences for both moisture and soil texture.
Write down the names of your plants to help you decide what type of potting soil you should buy. Group plants such as succulents, cacti or tropical plants. Note any unusual or difficult-to-grow plants in your collection, such as African violets or orchids.
Visit your local garden supply center and look for specialty mixes for your specific plants. These mixes contain the appropriate balance of soil, organic matter, nutrients and sand (if appropriate) to meet the growing needs of your plants.
Buy a soiless mix--typically labeled as seed starter--for planting seedlings inside in late winter or early spring. This mixture provides the ideal environment for germinating seeds and growing young seedlings.
Buy all-purpose potting soil if you intend to mix your own soil for large containers or pots. Mix equal parts all-purpose soil, peat moss, manure or compost and perlite to make a lightweight soil for container gardens.
Examine the potting soil before purchasing, if possible. Potting soil should be dark brown, free of clumps or large pieces of organic matter and smell like fresh earth. Stick with brand names you trust and that offer a money-back guarantee. Generic brands often add inferior products.
Purchase potting soil with additives to maintain moisture if you must leave plants for days at a time. Many contain granules that swell when watered and release moisture back into the soil gradually.