Olive trees are often used as ornamental topiary indoors, and on decks and patios. Caring for potted olive trees indoors is relatively easy as the plants are quite hardy -- there are, however, some aspects that require special attention such as location and fertilisation.
The position of an indoor olive tree is important. Choose an area where there is at least six hours of full sun each day for the best growth and bushy foliage. Olive trees should not be positioned near heat vents or radiators, nor should they be right next to a window -- the glass can act as a magnifier and scorch the tender olive leaves.
Olive trees need a reasonable amount of space for their roots, so choose pots that are 2.5 to 5 cm (1 to 2 inches) wider than the root system. Olive trees should ideally be transplanted yearly into a larger-sized pot so that continued growth and development of the plant is encouraged. Potted olive trees should have half the size of their root system in soil at the bottom of the pot, so taller pots are recommended for olive trees.
The soil used for indoor olive trees needs to be fast-draining and well fertilised. Olive trees are native to the Mediterranean area, so rich volcanic soils are ideal. From spring to the beginning of autumn indoor olive trees should be fertilised monthly to aid in their active growth period. Stop fertilisation before the first frosts and during winter.
Trimming of indoor olive plants is essential to maintain a manageable size and a decent shape. Pruning should be done after the spring buds are finished. It is not necessary to cut an indoor olive right back -- just clip the ends of the branches and this will encourage a full head of leaves to grow.
The main pest of indoor olive plants is soft-bodied scale. These are small insects that act like a tick and fix on to the trunk and stems of the olive and suck out sap. A natural insecticide like a neem oil soap solution sprayed onto the entire plant can effectively rid an indoor olive plant of scale. Dabbing rubbing alcohol directly on the scale is another method, although more time-consuming.