Tea is well-known in its cultivated form, where it is kept as a short bush for ease of harvesting, but a tea plant left alone can grow huge! Tropical strains of tea (Camellia sinensis var. aurantica) can grow to 17m if unclipped.There are some very hardy strains which are grown in China. They tend to be short, shrubby plants.
Tea plants grow best with even temperatures all year round, very wet summers and dry winters, so the conditions in the British Isles are challenging.You can grow tea with indoor protection with some success, you should be able to produce sufficent leaves for your own cuppa.
In very mild areas such as Cornwall, tea plants may be grown outside. They would need some protection from very wet winter weather and spring frosts. Tea can be grown in a pot and put outdoors during summer in less favourable parts of the country. Minimum temperature required is around -5ºC, depending on cultivar
From seed - just cover the seed and keep damp at 15ºC. Germination takes about 4 weeks. It is essential to use an ericaceous (acid) compost, such as that sold for growing rhodedendrons. Tea can also be grown from cuttings, either from firm heeled shoots taken in June, or near-ripe shoots with a heel taken in August-September. Both types should be kept in a shaded frame and grown for at least a year in a glasshouse before being planted outside.
Tea needs an acid soil (pH 4.5-7) so should be only watered using soft water or rainwater, and always grown in lime-free conditions.
Grow in light shade, and keep well watered during summer. Tea does not need a very fertile soil and so only needs an occasional application of liquid feed during the summer if grown in a pot. Mulching the plants with pine-needles or leaf mould can be beneficial.
In winter, allow the plants to dry out and only water sparingly. Plants in pots should be brought indoors to a light dry place such as a porch they need to be kept dry, more than protected from the cold. It is important that the plants should have a dry atmosphere around them, or they may develop mildew. Plants growing outdoors may benefit from a temporary shelter made out of clear plastic sheeting, like a tent, put up over them to prevent them getting too wet.
The part of the plant which is used is the tips of the new shoots, and these can be harvested at any time during the growing season.
Plant sources: Tea plants are sometimes available from garden centres as a novelty, but steady suppliers can be found through the Plantfinder.