Install a rootstock barrier

Where to install a rootstock barrier?

Logically, the anti-rootstock barrier is installed around the planting area of your bamboo. They are hardy and some can withstand temperatures down to -20°C. However, place them sheltered from cold, dry winds, as they are sensitive to these, preferably in partial shade, and in neutral or acidic soil, without excess lime, rich, moist and well drained.

You will therefore install your anti-rootstock barrier into the ground and vertically around the young plant. To increase the density of its culms, a bamboo hedge should be given at least 60 cm width by 1 m depth. The anti-rootstock barrier is therefore installed according to this minimum area.

When to install an anti-rootstock barrier?

Installing a rootstock barrier should be done just before planting your bamboo. Ideally, plant them in the ground in autumn, after the summer heat, in September/October, or in spring, in March/April.

How to install a rootstock barrier?

First, mark out on the ground the maximum spread of your bamboos. Once done, you can begin to dig the trench that will host your anti-rootstock barrier.

1.      Dig a trench

• Dig a trench 30 cm wide and at least 60 cm deep, ideally up to 1 m because bamboo rootstocks are sometimes able to penetrate deep enough into the soil to pass beneath the barrier. Warning: the trench must be 15 to 20 cm less deep than the height of your anti-rootstock liner, so that it protrudes sufficiently from the soil.
• If at this stage you find your subsoil is heavy and compact, lay a 5 cm-thick layer of drainage made of gravel.

2.      Position the barrier

• It is time to position your anti-rootstock barrier, angling it outwards from the trench.
• Depending on liner chosen, it may keep rolling up on itself. Hold it in place with metal rods, taking care to remove them once trench is filled.

3.      Make the installation watertight

Sealing is key to an effective anti-rootstock barrier! Rootstocks can easily run along the barrier and emerge via the cover if it is not sufficiently sealed.

• Ensure you leave at least 20 to 30 cm of liner for the cover between the two edges of the barrier.
• Backfill the trench containing the anti-rootstock barrier tamping the soil homogeneously.
• Cut now the excess liner, ensuring it extends 5 cm above the soil (rootstocks are also capable of crawling along soil surface when faced with an obstacle).

Diagram showing installation of an anti-rootstock barrier

4.      Plant the bamboos

Now that the anti-rootstock barrier is in place, all that remains is to plant your bamboos in the area it encloses.

For help, consult our advice on planting, pruning and maintaining bamboos.

Bamboo varieties that require a rootstock barrier

As briefly mentioned in the introduction to this article, some bamboos are inherently running (especially when planted in siliceous soils). This is notably the case for Pleioblastus, Phyllostachys, Sasa palmata, and Semiarundinaria fastuosa.

Bamboo shoots with exposed rootstock | © XIIIfromTOKYO

Be aware that other varieties are moderately running, and sometimes not running at all. This is notably the case for Fargesias bamboos, known as clump-forming, which naturally form a well-behaved clump.

Our running bamboo varieties

Phyllostachys bissetii - Bamboo

Phyllostachys bissetii is a medium-sized bamboo particularly prized for its ability to adapt to the harshest climates. Very bushy, its abundant foliage offers a fresh, bright green. Used to form screening and windbreak hedges, also effective against noise.

• Height at maturity 6 m

See the product sheet

Golden Bamboo - Phyllostachys aurea

Phyllostachys aurea is a moderately running, medium-sized bamboo. Recognisable by its culms ranging from chartreuse to almost golden that turn orange at ripeness. With its dense evergreen foliage and 6 m height, it makes a good screen.

• Height at maturity 6 m

See the product sheet

Pleioblastus pygmaeus Distichus - Dwarf Bamboo

Pleioblastus pygmaeus 'Distichus' is a dwarf bamboo and a running groundcover, low and compact. It has small, bright green leaves that form a beautiful tapetum for slopes, or elegant low hedges. It can even replace lawn in unworn areas.

• Height at maturity 60 cm

See the product sheet

Pleioblastus fortunei Variegatus - Dwarf Bamboo

Pleioblastus fortunei 'Variegatus' is a very small bamboo with an upright habit and dense foliage variegated cream-white on a green background. Used as groundcover, low hedge, edging or in a pot on the terrace. A fairly running variety, it requires a rootstock barrier to limit proliferation in open ground.

• Height at maturity 1 m

See the product sheet

Sasa palmata Nebulosa - Dwarf Bamboo

Sasa palmata 'Nebulosa' is a small Japanese bamboo forming a loose bush 2 to 3 m tall. It has very large glossy leaves arranged in palmate formations. Its culms are thin and take on a black hue at ripeness. Its rootstocks are relatively running.

• Height at maturity 2,50 m

See the product sheet

Semiarundinaria fastuosa - Medium-sized Bamboo

Semiarundinaria fastuosa has exceptional qualities. Used to create tall hedges. It is only slightly running, but still requires a rootstock barrier. Highly ornamental with a compact columnar habit, it offers lovely dense foliage.

• Height at maturity 7 m

See the product sheet

Useful link

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