Plant growth is dependant upon a steady supply of nutrients! The nutrients in any soil are soon depleted.
Plants need soluble fertilizers at one-half the recommended dose, fertilize every 3rd to 4th watering during the summer months. During Fall and Winter, fertilize every 2-3 months. Time-release fertilizer may be mixed into the potting medium when repotting. Never water a very dry plant with fertilizer!
A common mistake of most beginners is to repot plants long before it is necessary. Roots growing out of the bottom of the pot do not necessarily mean that the plant needs repotting. If the plant is lifting out of the pot, or if inspection of the root system show that there is no room for root growth, then the plant should be repotted. Spring is the best time to repot indoor plants. Repotting then will ensure more new growth and less frequent watering during the hot, sunny summer.
To see if a plant needs repotting: Carefully knock them out of them out of their containers. If they retain a pot shape and no soil falls away, pot in a container 1-3 inches bigger (diameter).
Be sure to use a light, soil less mix for repotting. Commercial “potting soil” is ordinarily unsuitable for indoor plants. It is not reliably sterile and is too dense. A potting medium for indoor plants should be moisture retentive, well drained, and sterile. A mixture of two-thirds sphagnum peat moss and one-third perlite is an ideal medium for growing indoor plants.
Carefully knock the plant out of its old pot (do not pull on the plant). Remove any loose soil especially if it is a heavy mix. If you are repotting into a undrained container, put a layer of perlite (1-2 inches in small containers and more in larger) at the bottom as a drainage layer (to prevent roots from sitting in water).
Place enough soil in the bottom of the pot to have the top of the root ball near the top of the container (~1 inch below in small containers ~3” below in large). Set the plant in the pot and gently pack soil around the root ball with your fingers. Thoroughly water the plant until all of the soil is moist and water drains out the bottom. (In an undrained container fill with water, wait a few minutes and them carefully tip on its side to completely drain the excess water out.)
Plantscape Designs Inc. fertilizes your indoor office plants on a monthly basis except during the months of December,January, February because of low light conditions here in the Cambridge Ma area.