Citrus fruits include the lemon, orange, tangerine and grapefruit. Generally, it takes eight to ten years for such plants to produce fruits if they are grown from pips. Increase by budding or grafting on to seedling stock or by cuttings are quicker methods of securing fruiting specimens, and are essential for specific varieties. Budding is done in early spring, grafting in late summer.
I grew some lemons from cuttings which are now in 9-in. pots and produce 30 to 40 fine large fruits each year.
As a growing medium for the lemons I use John Innes No. 3 Potting Compost to which a little more peat has been added for citrus fruits seem to appreciate a slightly acid. They also need a moist atmosphere and free ventilation in the growing season.
They do not need high temperatures during winter and will come to no harm if the temperature falls to 4°C. (40°F.). Their greatest enemy is brown scale which I control with white oil emulsion or a weak solution of malathion.
In time, the trees can become far too large for the sun lounge or conservatory. This can be countered by not allowing the trees more root area than that provided by a 9-in. pot. If this is done, then the plants should be removed from their pots each year so that some of the old soil can be teased out from among the roots and new soil added when they are returned to the pots.
The easiest way to increase citrus plants is by seed, but as already mentioned it will take several years for fruits to appear. Germinate the pips in seed compost in a propagating frame with a temperature of 13°C. (55°F.). Pot up the seedlings singly using 3-in. pots and John Innes No. 1 Potting Compost.
Cuttings can be taken from April to September and rooted in a propagating frame at a temperature of 18°C. (65°F.).