Bamboos in containers

Pleioblastus variegatus, with its pale green leaves streaked in white, creates a low display and is ideal for placing on a patio in a small garden.

Are bamboos suitable for containers? A specialist explains how to grow them in your garden.

For upon |Many bamboos grow remarkably well in containers displayed on a patio or terrace. The range of bamboos in containers is wide and, while some are relatively low, others are tall and dominant. Especially avoid putting tall ones in windswept positions. Some bamboos have attractive variegated leaves, while others are totally green, but nevertheless attractive. Contrast variegated forms by interspersing them with all-green types.

Choosing container for bamboo

Large pots, wooden tubs or square boxes are ideal homes for bamboo (see below for sizes). Ornate, wide-based pots are ideal for low-growing bamboos, especially when they are positioned in exotic gardens. Large tubs and square boxes are better suited to taller-growing bamboos, and are usually left in one position until the compost is congested with canes and division if necessary.

• Ornate containers are superb for use in Japanese-style gardens.
• Traditional barrel-type containers are ideal for rustic gardens.
• Square containers, with a fancy decoration, have a clinical nature.
• Plain, square, wooden containers are ideal for relaxed, informal patios.

Compost for pots and containers

It is possible to fill a container with garden soil, but this may introduce pests that highlight the vagaries of ordinary garden soil. It is far better to use a mixture of equal parts peat-based compost and loam-based potting compost; the peat-based type increases the compost’s ability to retain moisture, while the loam-based type introduces fertilisers and gives containers greater stability, which is essential in windy areas near to the corners of buildings.

For small, low-growing bamboos a container holding at least 10 litres of compost – the equivalent of about 2.5 gallons – is essential. Tubs and square boxes, which suit tall bamboos, need to be large enough to hold 30 litres or more of compost. This is equal to about 8 gallons.

Small pots are usually portable, and bamboos can be planted before you position the container. However, tubs or square boxes are best filled and planted in situ. When doing this, ensure that the best and most attractive side of the plant faces towards the main viewing position.

Planting bamboos in containers

Ensure that the container is clean and suits the area – it should be decorative for exotic areas but rustic for more rural settings.

Step 1
Check that drainage holes in the base are not blocked. Place a large tub in position; small ones can be moved later. Stand large wooden tubs on three bricks to reduce the risk of the base remaining wet and decaying. Fill the base with broken pieces of clay pots or a thin layer of pebbles.

Step 2
Fill the container to about half full with compost (see page 12 for the mixture). Gently firm it. Place the bamboo on top and check that the surface of the soil ball is about 36mm (1½ in) below the rim.

Step 3
Carefully draw and firm compost in layers around the roots until the surface is about 25 cm (1 in) below the container’s rim. This will allow for larger settlement of the compost, and after a month or so it will leave a watering depth of about 36 mm (1½ in).

Step 4
Use a watering-can – with the rose turned upwards – to water the compost. Several waterings will be necessary before the compost is thoroughly moist.

Congested Plants
When the compost is congested with roots, in mid-spring either repot the plant into a larger container or remove, divide and repot the divisions in 2-3 pots. Always thoroughly water the compost and keep it moist in the summer, during the first two years.

Take care

• Use clean, moisture-retentive compost, not garden soil.
• Stand the container out of direct sunlight.
• Position the container out of strong draughts that dry the compost and foliage.
• Use large containers, especially for tall bamboos. Large containers hold more compost than small ones and are less likely to dry out rapidly in summer.
• Keep the compost moist – it may mean watering several times a day during summer.

Winter care

During winter – especially in cold and exposed areas – the relatively small amount of compost in containers is in danger of freezing and damaging roots of bamboos. Therefore, in autumn reduce the amount of water added to the compost, keeping it slightly moist rather than saturated.
If winters are especially severe, wrap the container and compost in straw and sacking. Also closely cloak the sacking and straw in a sheet of polythene to prevent them becoming wet and subsequently freezing. Remove these coverings as soon as the weather improves.
Bamboos in small containers are especially at risk during winter and can be placed in a cold greenhouse.
If the canes and leaves become covered with snow, gently shake them before it freezes. Lightly tapping the foliage with a long cane is another way of removing unfrozen snow.

Bamboos for containers

Low displays in containers
Pleioblastus pygmaeus
Pleioblastus variegates
Pleioblastus viridistriatus

Medium displays in containers
Fargesia murielae
Phyllostachys nigra
Thamnocalamus tessellatus

Tall and dominant displays in containers 
Bambusa multiplex
Fargesia dracocephala
Fargesia nitida
Fargesia robusta
Fargesia utilis
Phyllostachys aurea
Pseudosasa japonica
Semiarundinaria fastuosa
Semiarundinaria yashadake kimmei
Shibataea kumasaca
Thamnocalamus crassinodus
Thamnocalamus spathiflorus

This extract is taken from The Bamboo, Grass & Palm Specialist, by David Squire, published by New Holland, priced £4.99 from all good bookshops. Alternatively, purchase The Bamboo, Grass and Palm Specialist from Amazon.