Part of giving proper care to plants of all sizes and ages is repotting, to encourage healthy growth and refresh the soil. Young plants need to be repotted more frequently because they are rapidly growing, while you should repot older houseplants every few years. In general, it is time to repot a plant if it is root bound, meaning that the roots are fighting for room in the pot. The repotting process is straightforward, and your plants will appreciate it immensely.
Approximately once a year, gently unpot houseplants to check on the health of their roots. Do this by tipping the plant upside down with one hand and gently pulling the plant out onto your other hand. Larger plants may require two people. Healthy roots will be firm and white or pale in color, while unhealthy roots will be dark and slimy, suggesting rot.
Trim off unhealthy roots before replacing the plant in its old pot or repotting it, if this is needed. If the roots have formed a dense ball which is exactly the size of the pot, you should repot the plant in a pot approximately one third larger. If the roots have not overgrown, replace the plant in the old pot with fresh soil.
The best time of year to repot plants is in the spring or early summer, when they are growing. To repot a plant, start by laying down a layer of soil in the new pot. Separate the roots of the plant before you repot it, so that they can spread out in the new pot. Place the plant into the middle of the pot and press soil down around it so that the plant is evenly surrounded with new soil, and build up the level of the soil to approximately one inch (three centimeters) below the rim of the pot. Water the plant thoroughly, adding soil if necessary to bring the soil level back up.
After you repot the plant, it may experience shock for several days. This is quite normal, as repotting can be a traumatic experience. Keep the plant in a warm place, and make sure that the soil is moist, although not waterlogged. The plant will settle into its new home and begin to put out new growth, as long as it is well cared for.
Be careful with some plants which you do not need to repot as frequently. Certain bulbs, for example, should be allowed to break pots with their roots to encourage blooming. Other plants such as cacti and succulents prefer to be left in the same pot, although you should renew the top layer of soil every year. Other plants, especially young plants and cuttings, will need to be repotted more frequently because they are growing: assess the needs of your plants individually.