Bamboo barrier alternatives: fabric, metal, concrete or root pruning?

How do the alternatives compare?

Three options can hold running bamboo: a continuous plastic sheet, a concrete wall with no cracks, or root pruning done every year. Fabric, lawn edging and sheet metal leave gaps, stop too shallow or rust.

This guide is about running bamboo. Most clumping bamboo needs no barrier: see running vs clumping bamboo.

What does any bamboo barrier have to do?

1. Reach below the rhizomes. Most running-bamboo rhizomes stay in the top 12 to 18 in of soil.
2. Have no gaps. A rhizome that meets a barrier often turns and follows it. A loose seam, crack or rust hole is a way through.
3. Stand above the soil. If soil or leaves cover the top, rhizomes cross it unseen.
4. Hold up in damp soil. It can't rot, rust or crack where you can't see it.

No option ends the upkeep. Walk the line once or twice a year and cut any rhizome that crosses.

Will landscape fabric stop bamboo?

No. Landscape fabric is weed cloth, woven to let water and air through while it blocks light. Washington State University Extension notes that weed roots grow into it and it breaks down over time.

It isn't made to turn a rhizome, even standing on edge in a trench.

Is metal lawn edging deep enough for bamboo?

No. Steel lawn edging is commonly sold 4 to 8 in tall, and part of it stays above the soil. Most rhizomes stay in the top 12 to 18 in of soil, so many run below a 4 to 8 in edge.

Use it for a lawn edge or to hold mulch.

Can I use a shallow or thin plastic edge, like Grass Barrier?

No. Grass Barrier is 10 in tall and made for lawn grass. Set with a 2 in lip, it reaches 8 in down, and many rhizomes run deeper.

Thin plastic falls short too. The University of Maryland Extension's minimum is 60 mil polypropylene or HDPE, and it says 80 mil may be ideal for mature or vigorous groves. Missouri Botanical Garden gives a lower 30 to 40 mil, but go by the 60 mil minimum.

Can I use sheet metal or roofing panels?

They can hold bamboo for a while. How long depends on the soil and the coating, and we found no reliable figure.

Missouri Botanical Garden and the New York Botanical Garden both prefer plastic, because metal rusts and needs many seams. The Royal Horticultural Society does list corrugated iron, if no gaps are left between sheets. That is the hard part.

A common corrugated steel panel is about 26 in wide and 8 or 12 ft long. Set on edge with a 2 in lip, it reaches about 24 in down.

Worked example: seams in a 100 ft straight line

Overlap each panel seam 12 in, so each added panel covers 1 ft less than its length. With 12 ft panels, 12 + (8 × 11) = 100 ft. With 8 ft panels, 8 + (13 × 7) = 99 ft is short, so 8 + (14 × 7) = 106 ft.

At 36 in, the line needs 100 + 1 = 101 ft for its one joint. Order two cuts in 5 ft steps, such as 55 ft + 50 ft, and one connecting kit.

Does a poured concrete wall work?

It can, if it is deep enough and never cracks. It also takes far more work and money, and it is hard to change later.

A bamboo nursery in Virginia describes a wall 4 in wide and 36 in deep, with steel rebar at 1 ft and 2 ft down. Along 100 ft, that is 4/12 ft × 3 ft × 100 ft = 100 cubic feet. At about 0.6 cubic feet per 80 lb bag of mix, 100 ÷ 0.6 = about 167 bags.

Cracks are the weak spot, and the University of Maryland Extension lists concrete among the materials to avoid. A sidewalk, patio or driveway is not a barrier either: rhizomes can run under it.

Can I prune the roots instead of using a barrier?

Yes, if you keep at it. Missouri Botanical Garden says cutting the rhizomes with a spade or saw works if you do it every year. Skip a year, and new rhizomes get past your line.

1. Call 811 before you dig.
2. Mark a line about 12 to 20 in outside the edge of the planting.
3. Cut straight down with a sharp spade, at least 12 in deep, overlapping each cut. Old rhizomes may need a mattock the first time.
4. Pull out the cut pieces on the outside of the line.
5. Repeat once or twice a year, in late summer or fall, while the new rhizomes are tender.
6. Mow or cut shoots that come up outside the line in spring.

Or keep a trench 12 in wide and 12 in deep along the line, open or filled with sand, where crossing rhizomes are easy to cut.

A spade cut reaches about 12 in down. Most rhizomes stay in the top 12 to 18 in, so some run below your cut. Keep watching for shoots outside the line.

It fits a small planting you can reach all the way around. It is not for a long property line, a line you can't dig along, or a spot where one missed year puts bamboo in a neighbor's yard.

Why is continuous HDPE sheet the usual choice?

It does all four jobs, with few joints and nothing to rust.

• Few joints. Each cut is one continuous piece, up to 175, 100 or 70 ft by depth. A joint is an overlap of at least 12 in, clamped with the stainless connecting kit.
• Nothing to rust or rot. HDPE holds up well to the chemicals found naturally in soil.
• It turns rhizomes up. Set the smooth face toward the bamboo and tilt the top slightly outward. Rhizomes turn up toward the 2 in lip, where you can see and cut them.

Bamboo Shield comes 24 in deep (60 mil), 30 in (80 mil) or 36 in (100 mil), so every depth meets the 60 mil minimum. It is made in the USA. The depth goes by your USDA zone and the size of your bamboo: see how to choose a depth.

A barrier also makes the yearly check smaller: you look for rhizomes crossing a 2 in lip instead of cutting a 12 in deep line. See the Bamboo Shield install manual for each step. Call 811 before you dig. The Bamboo Shield product page has prices and lengths.

Who doesn't need a barrier at all?

• Clumping bamboo with room to widen. Cut unwanted shoots at ground level.
• Anyone who wants the bamboo gone. A barrier keeps bamboo in place. It doesn't remove it.

With any option, bamboo already outside your line keeps growing until you dig it out.

Common mistakes

• Counting a fence, walk or driveway as a barrier. Rhizomes go under them.
• Leaving gaps between metal sheets. Every seam needs a tight overlap.
• Burying the top of any barrier under mulch or soil.
• Taping plastic joints. Tape is not a seal. Clamp each joint.

FAQ

Can I use landscape fabric or metal edging instead of a bamboo barrier?

Not for running bamboo. Roots grow into thin weed cloth, and metal edging is commonly 4 to 8 in tall, while most rhizomes stay in the top 12 to 18 in of soil. Use a solid sheet such as HDPE, at least 60 mil thick and 24 in or more deep.

Is concrete better than plastic for bamboo?

Not usually. A concrete wall 36 in deep holds bamboo only while it has no cracks, and a crack lets rhizomes through. It is also far more work: about 167 bags of 80 lb mix for 100 ft, plus forms and rebar.

Can I control running bamboo without a barrier?

Yes, if you prune the rhizomes every year, because a skipped year lets them past your line. Once or twice a year, in late summer or fall, cut straight down at least 12 in with a sharp spade. Cut 12 to 20 in outside the planting and pull out the cut pieces.

Do plastic bamboo barriers fail after a few years?

We don't give a lifespan. When bamboo gets past a plastic barrier, check the setup first. Look for an unclamped joint, a buried top edge, loose backfill, or an end that stops before the grove does. See how rhizomes get past a barrier.