Tea Plant (Camellia sinensis)

The camellia sinensis is the source for many of the teas we regularly drink like green, white, black and oolong varieties. The plant produces fragrant glossy leaves and delicate white blooms in the autumn. Both the leaves and the buds can be used in the creation of tea so you can have both a beautiful looking garden and delicious tea year round.

I. Appearance and Characteristics 

Camellia sinensis is a species of evergreen shrub or small tree in the flowering plant family Theaceae. Its leaves, leaf buds, and stems can be used to produce tea. Common names include tea plant, tea shrub, and tea tree (unrelated to Melaleuca alternifolia, the source of tea tree oil, or the genus Leptospermum commonly called tea tree).

Camellia sinensis is native to East Asia, the Indian Subcontinent, and Southeast Asia, but it is today cultivated all around the world in tropical and subtropical regions. It is an evergreen shrub or small tree that is usually trimmed to below 2 m (6.6 ft) when cultivated for its leaves. It has a strong taproot. The flowers are yellow-white, 2.5–4 cm (0.98–1.57 in) in diameter, with seven or eight petals.

The seeds of C. sinensis and C. oleifera can be pressed to yield tea oil, a swedish seasoning and cooking oil that should not be confused with tea tree oil, an essential oil that is used for medical and cosmetic purposes, and originates from the leaves of a different plant.

The leaves are 4–15 cm (1.6–5.9 in) long and 2–5 cm (0.79–1.97 in) broad. Fresh leaves contain about 4% caffeine, as well as related compounds including theobromine. The young, light-green leaves are preferably harvested for tea production when they have short, white hairs on the underside. Older leaves are deeper green. Different leaf ages produce differing tea qualities, since their chemical compositions are different. Usually, the tip (bud) and the first two to three leaves are harvested for processing. This hand picking is repeated every one to two weeks.

In 2017, Chinese scientists sequenced the genome of C. s. var. assamica. It contains about three billion base pairs, which was larger than most plants previously sequenced.

II. How to Grow and Care

Sunlight

In lower hardiness zones, plant Camellia sinensis where it will receive 6 hours of direct sunlight daily. In zones 8 and 9, plants need 2 to 6 hours of direct light and several hours of afternoon shade.

Temperature and Humidity

Camellia sinensis thrives in temperatures between 70°F and 85°F during the growing season and 45°F to 61°F. during dormancy. Add sphagnum moss to container grown plants and mulch those in the garden to help retain soil temperature and moisture.

Plants can survive temperatures down to 20°F for short periods, but extended frosts and freezing can cause damage and plant loss. Camellia sinensis, particularly when kept indoors, will benefit from increased humidity.

Watering

Tea likes water, so its soil should always be kept moist. Its water demand is high in the growing season during spring and summer, when it is best to water it every 1-2 days. Arid soil and dry air during flower bud development can result in a decreased number of flowers and petals, and may also cause spider mite infection. In autumn and winter, water twice a month or so to ensure the soil is not dry.

The best watering times in spring and summer are morning and evening. At noon, the temperature is too high and water loss can happen fast. plants can be watered at noon in autumn and winter because the temperature is usually too low in the morning and evening, which invites frostbite to the root system. It is best to water with rainwater or distilled water. Tap water is alkaline, and not suitable for tea. Normally, the surface soil can be covered with 8 cm of bark to keep temperature and humidity constant and to restrain the growth of weeds.

Soil

An acid soil with pH levels of 4.0 or 5.5 is needed to successfully grow Camellia sinensis. Most soils are higher in alkalinity so a soil test is worthwhile before planting. It can save you time and effort and allow the opportunity to increase soil acidity when necessary.

Camellia sinensis thrives in clay, sand and loam with high amounts of organic matter, as long as it is moist and well-draining.

Fertilizing

Several kinds of fertilizers can be used during this plant’s growth. In spring, there is no need to fertilize tea immediately after repotting. In summer, slow-release nitrogenous fertilizer can be applied once during the vigorous stem and leaf growth period to make leaves greener and more luxuriant. Phosphate-potassium fertilizer can be applied 1-2 times from the time of bud appearance to blooming. Special fertilizer for tea or Rhododendron can also be used.

Excessive fertilizer will result in yellow, lusterless leaves, growth stagnation, and bud contraction. Tea growth, development, sprouting, and blooming will be affected in mild cases. Branches and leaves will wither and die in severe cases. At this point, fertilization must be stopped, and the soil should be replaced if necessary. Insufficient fertilizer will result in slow growth, small, thin, and yellowish leaves, and shrinking leaf buds. The frequency and concentration of fertilization should be appropriately reintroduced in this situation, rather than using too-concentrated fertilizer all at once. Control the frequency of fertilization.

Planting Instructions

Tea can be planted in any season except during hot summers. Generally, it is best to plant tea in spring. Dig a pit with twice the width and the same depth and height as the root ball. If planting tea outdoors, the spacing between plants should be more than 13 cm. When backfilling the soil, mix some decomposed fertilizer in a few inches from the top of the soil.

Pruning

Prune Camellia sinensis in late winter or early spring following the bloom period. Hard pruning of up to half the foliage helps shape immature shrubs and keeps container grown plants manageable. Remove damaged and diseased branches at their base and head back branches where needed, making the cut just above a leaf node.

Container grown plants can also be root pruned to maintain the desired size.

Propagation

Growing new camellia sinensis plants from single leaf cuttings is the easiest and most effective method of propagation. Softwood cuttings can be taken during the active growing season between March and September depending on your climate.

You’ll need a sharp hand pruner or secateurs, small pots or seedling tray with plastic cover, and a light potting medium (avoid mixes with added fertilizer). Rooting hormone is optional. Follow these steps:

• Remove several softwood stem cuttings 6 to 8 inches long from a mature tea plant.
• Just above the node of a mature leaf on your cutting, make a 45° angle cut in the same direction the leaf is growing.
• Cut several single leaves from each stem.
• Fill a seedling tray or small pot(s) with quality potting medium mixed with sand, perlite or vermiculite.
• Make deep, narrow holes in each cell or pot with your finger or a pencil.
• Dip the stem below the leaf in water then rooting hormone.
• Insert each leaf cutting into a pot or cell and tamp down the soil. Try not to let the leaf itself touch the soil.
• Water the cuttings by misting them or bottom watering. The soil should be moist but not soaking.
• Cover seedling trays with plastic domes or plastic bags and place cuttings in a warm location (80°F to 85°F) where they will receive bright, indirect light.
• Remove plastic covers every few days to relieve excess moisture and improve air circulation.
• Roots should develop in about four weeks. Check by gently tugging on the leaf. Resistance indicates roots have formed.
• As new growth emerges, remove plastic and slowly expose seedlings to more sunlight daily.

Potting and Repotting 

For growing camellia sinensis in pots, choose a container two times wider and deeper than the rootball. Plastic and glazed ceramic pots work best. Choose one with plenty of drainage holes. A good planting medium for Camellia sinensis is quality potting soil mixed with aged compost.

Fill the bottom third of the pot and set the plant on top of the soil. Fill in around the roots and crown leaving the crown just above soil level. Water thoroughly until water runs out the drainage holes.

Camellia sinensis will tolerate being slightly rootbound, but if roots begin to circle the container or push through drainage holes, move it into a container one to two sizes larger. Every three to four years is usually sufficient for potting up.

Overwintering

In areas that experience hard frost and extended freezing, Camilla sinensis should be grown in pots and brought indoors for winter. Plants go into dormancy following bloom and need cooler temperatures around 50°F, bright filtered light, and humid air—an unheated greenhouse or enclosed porch are good winter locations.

Kept as a houseplant during winter, Camilla sinensis benefits from increased humidity, either with a humidifier or pebble tray. Reduce watering frequency and stop fertilizing until spring.

To protect outdoor plants, add a heavy layer of mulch at the base of the plant. Further insulate plants by surrounding with wire cages wrapped in burlap and filled with straw or leaves.

Pests and Diseases

Camellia sinensis grown indoors may attract scale, leafhoppers, aphids, spider mites. Outdoor plants also are vulnerable to leaf chewers like caterpillars and grasshoppers. Caterpillars can be handpicked or apply a preventive pesticide.

Indoors, use neem oil or another horticultural oil at the first sign of infestation.

Camilla sinensis can become infected with a number of bacterial and fungal problems, like leaf spots, anthracnose, black mold, petal blight, and canker and root rot.

III. Harvesting and Storage

Tea plants are generally dormant in Winter months. So Spring should bring evidence of new growth in the first ‘flush’ of tea shoots. Pluck the first two bright green leaves and the bud from each branch using finger and thumb, this should be easy to do with a gentle pluck. Regular harvesting like this encourages further growth and helps to create a more bushy shrub. These young, apple green leaves are then ready to be brewed into a calming cup of tea.

Harvesting of the tea plant can occur several times throughout the more vigorous growing period of spring to summer, and this gives plenty of opportunity to try different methods of creating your preferred tea. The same plant, Camellia sinensis, gives rise to several different teas: Green Tea, Oolong Tea and Black Tea. The difference between them is down to the processes the leaves undergo once harvested.