How bamboo grows.
Bamboo is a member of the grass family. The stems that you will receive in the pot will not grow any taller or thicker. As the root system develops new shoots will appear in spring. These will be taller and thicker stems than the previous year's stems until the optimum height is reached as the years go by. So the oldest stems are the smallest. BAMBOO DOES NOT GROW LIKE A TREE.
A new emerging shoot in spring. Note how much thicker it is than the previous year's stem (top left of picture).
Selection of the site.
Select the position for your bamboo carefully. Most bamboos are reasonably behaved, as in the clump forming bamboos of Borinda, Drepanostachyum and Fargesia. Height is probably the most important factor you will need to consider, as well as the amount of sun received - contrary to popular belief, not all bamboo like to be in full sun.
Growing very tall bamboos over 5 metres will require at least a space of 1.25 metres square and with the 6 metres+ bamboos a space of 2 metres square would be better.
Phyllostachys praecox (above) will grow to over 6 metres tall and as you can see requires the room to do so.
The newly introduced tall growing Borindas (above) do not take up so much area to achieve their potential.
Some bamboo are rampant spreaders and will often need plenty of space or containing to prevent them from spreading too far. Mostly these are of the genus Sasa. Containing can be done by digging a barrier to encicle the plant to stop the rhizmoe system spreading where you do not wish it. Rhizome Barrier
Planting
Dig a large hole, twice the depth and spread of the rootball of the plant, this will give the bamboo open ground in which to establish itself over the first few years. Dig in plenty of organic matter, (we use mushroom compost or well-rotted manure) particularly if your ground is sandy or poor in nutrients. Plant the bamboo so that the rootball is buried maybe an inch (2-3 cm) under the surface as this will provide stability and help retain water. Bamboo will survive almost anywhere, but will do exceptionally well if given plenty of healthy nutritious food and water. Water is especially necessary in spring when the new shoots are extending and requiring a lot of water. Very heavy watering once a week is better than a little every day. Giving a lot of water will mean that you will have watered the root system to the bottom. We have noticed that the newly introduced Borindas require a lot of water in the spring and will readily abort their new shoots if they are on the dry side.
Aftercare
Water your bamboo well until the plant is established and feed every other year in late spring (i.e. after the first shoots have emerged and reached full height), preferably with a mulch of well-rotted manure or a multi-nutrient feed.
With Phyllostachys and Semiarundinaria bamboos, which have more open groves with strong outstanding culms, every two to three years remove the smaller, weaker canes. This leaves the more upright stronger culms to show off their best and allows more light into the centre of the grove. With Fargesia and other clump forming bamboos this is usually not necessary. Some dwarf bamboos may benefit from cutting back to the ground in mid-spring as the new growth appears to help promote leaf growth and vigorous shooting.
