Many varieties of potting soil exist. Sandy, porous mixes provide the required drainage for cacti and succulents, while potting soils rich in organic matter are used for aquatic plants. Some potting soils have no actual soil in them, instead they consist of a combination of compost, peat moss, bark, perlite and other materials. The label on the potting soil bag indicates the types of plants it is best used for, removing much of the guess work.
Fill the planter half-full with the potting soil. Use planters with at least one pre-drilled drainage hole in the bottom so the potting soil does not become soggy after watering.
Set the nursery plants on top the potting soil. If you are planting multiple plants in one container, space them at half the distance recommended on the plant labels.
Place additional potting soil under the plants as needed to elevate their crowns so they sit 2 inches beneath the rim of the pot. The crown is where the stems emerge from the root system and this area must not be buried at planting.
Fill in around the plants with additional potting soil until the soil level is even with or just beneath the plant's crown. Firm the soil surface around each plant gently with your hands.
Water the pot from the top until the excess moisture drains from the bottom drainage hole. Water at the base of the plants so the foliage doesn't get wet and also to prevent potting soil from splashing up out of the pots.
Water the potting soil when the top 1 inch begins to feel dry, except for cactus soils which are watered when the soil is almost dry throughout. Avoid letting everything but cactus mixes from drying out completely, as rehydrating dry potting soil is difficult.
Fertilize the potting soil regularly to replace the nutrients. For most plants, use a general purpose, soluble fertilizer once a month, applying it at the label recommended rate. Only fertilize when plants are actively growing.