- As the exposed portion of a plant grows, so does its network of roots. Consequently, a growing plant must be transplanted into a larger pot to allow room for root growth. A common error is to do this too frequently, maximizing the risk of damaging the plant. Plants tend to grow at a uniform rate if their conditions are kept regular, so observe this growth rate to give yourself an idea of when the plant needs to be re-potted. Another thing to remember is that some plants, such as begonias, do much better in loosely packed soil rather than soil that has been pushed down into a solid block.
- Most plants need just enough water to keep the body of the soil moist when the surface feels dry. However, when flowers are blooming they will need slightly more than non-flowering plants, or flowering plants which are not in bloom. Cacti are an obvious exception as they need very little water and should be kept in very gritty soil with good drainage, so as not to remain moist.
- Plants kept indoors are unlikely to receive the same high levels of sunlight as plants kept outside. This can be remedied by rotating pots so that all plants receive the same amount of sunshine. Rotating pots also makes it less likely that plants will grow crooked at as they lean toward the sunlight. Most plants gather the majority of their sunlight in the morning, so move them to an east-facing window or place them outside in the morning to allow them to do this.
- Nutrients in the soil are removed by watering, so houseplants require additional fertilization to achieve their full potential. However, large amounts of fertilizer can damage the plant and its roots so caution is advised. Most houseplant fertilizer instructions recommend diluting the fertilizer to a ratio of 1 tsp. per gallon, but a lower dose -- as low as 1/5 tsp. per gallon -- will suffice. The important thing is to observe how the plant responds to the fertilizer; if it appears to be a detriment to the plant's health, stop immediately.