There is some fascination in having a lemon or lime tree and sitting in your conservatory reaching out to put the fruit in your drink.
If you want a plant to bear fruit buy a dwarf houseplant from a garden centre as a tree grown from pips will grow too large and leggy for your room before it bears fruit.
Summer is the usual flowering period but calamondian oranges may produce white fragrant flowers and small bitter fruit all year round, the fruit can be used whole to make marmalade. To improve fruit production, pollinate flowers by dabbing each with cotton wool.
Basic requirements are good drainage and careful watering; do not over water as citrus do not like to be kept wet. Misting the leaves regularly improves the foliage quality. Keep the plant out of draughts in a cool, but not cold room with plenty of light. In summer plants prefer to be outdoors in a sunny position.