What's the difference between clump forming and running bamboo?
Bamboo are architectural plants perfect for adding structure, height and movement to your garden. Their highly ornamental canes and lush evergreen foliage has a distinct Japanese feel and there are varieties suitable for uses ranging from hedging to mixed border plants and centre pieces. Easy to grow and fully hardy, there are a few hundred varieties suitable for the British climate. A key distinction between them is clump-forming and running varieties. Each are very different and have their own specific uses and benefits, as explained below.
Root System and Vigour
- Clump-Forming Bamboo - Clump-forming bamboos have a root mass like normal ornamental grasses, spreading gradually out from the centre and never springing up canes more than 5-10cm from the existing plant.
- Running Bamboo - Running bamboos spread by independent, horizontal underground stems from which aerial canes develop. It's not unusual for these underground stems to extend and shoot up another cane 60-80cm away from the original planting site. This means their roots need to be contained to prevent them from spreading aggressively and colonising parts of the garden you didn't want them to.
Compact root ball of clump forming bamboo
Height and Spread
- Clump-Forming Bamboo - Clump forming bamboos usually grow to less than 5 metres (15 feet) tall because of their small, delicate culms. They will grow equally as wide over time if left to their own devices.
- Running Bamboo - Grow to their mature height quickly and spread aggressively. Some will reach up to 8 metres whilst others top out at under 1 metre making them useful for ground cover. You'll need to contain the roots (the easiest solution in the long term in our view) or undertake twice annual root pruning. See our article on how to grow and care for bamboo plants for more details.
Growth Rate (Rough rule of thumb)
- Clump-Forming Bamboo - The new canes of clump forming bamboos can grow up to 30-45cm (1-2 feet) taller each year until the plant reaches its eventual height.
- Running Bamboo - The new canes of running bamboos typically grow 90cm to 1.5 metres taller each year until it reaches it's eventual height.
- Clump-Forming Bamboo - Whilst there are cold hardy as well as tropical varieties of clump forming bamboo, in general they tend to be a more susceptible to the cold than their running counterparts. Expect to have to provide frost protection in the depths of the winter, particularly if you'll be growing them in a container without the benefit of masses of surrounding soil for insulation. A good choice for containerised clumping bamboos is to bring them into a frost free area such as a garage or outbuilding when frost is forecast.
- Running Bamboo - All varieties of running bamboo are very hardy and should have no issues in any parts of the UK. In exposed locations leaves may become scorched by the wind but it takes a lot for running bamboos to be taken out completely.
- Clump-Forming Bamboo - Ideal for using as specimens in lawns, mixed border planting or even containers. Container grown plants will normally grow happily for up to 5 years before you'll need to refresh the compost and divide or consider a larger pot. Less favoured as hedging plants because of their narrower base and arching stems, which makes them wide at the top with gaps at the base.
- Running Bamboo - Great for forming a windproof hedge or screen but constricting the roots to prevent them from becoming unruly is an absolute must. If you use them for container-growing you'll need a pot or planter this is very strong and should be prepared to lift, divide and re-pot every 2-3 years. Running bamboos provide the look many people want from their bamboos and with proper containment can be a joy to grow.
Types of Running Bamboo
Phyllostachys aureosulcata f. spectabilis
Pleioblastus pygmaeus Distichus
Types of Clump-Forming Bamboo
Fargesia murielae 'Simba'
Fargesia murielae 'Volacno'
Fargesia murieliae 'Winter Joy'
Fargesia murieliae 'Rufa'