How to Plant a Moso Bamboo

When and where to plant

Moso Bamboo is hardy in zones 7 through 10 and grows best in full sun, six or more hours of direct light each day. It tolerates light afternoon shade in the hottest southern zones but will lean and thin out in deeper shade. The soil at the site needs to drain freely. Heavy clay holds water and rots the underground stems, so on poorly drained ground, raise the bed by six to twelve inches and amend with compost.

Plant in spring once the ground has thawed and night temperatures stay reliably above 35°F. Roots establish through the warm months and the plant goes into its first winter with a deeper hold on the soil.

Be honest about the space this plant needs. Moso is a giant timber bamboo, with canes that mature at fifty to ninety feet tall and six inches across, and it runs aggressively underground. A single planting will push new shoots fifteen to twenty feet beyond the original clump within a few years if nothing stops it. Plant at least twenty feet from any property line, foundation, septic system, or paved area you care about, and plan on a root barrier or container from day one.

Planting a container-grown bamboo

The single most important rule for Moso Bamboo is containment. This is a running bamboo, which means it spreads by sending out underground stems that pop up new canes ten to twenty feet from the original plant. Without a root barrier or a sealed container, the planting will move into your neighbor's yard, through a vegetable garden, and under fences within a few years, and removing established runs is one of the hardest jobs in the landscape.

1. 1
   Mark the planting area and dig the barrier trench Decide how large you want the grove to be at maturity, then mark a circle or rectangle at least eight by eight feet for a single starter plant. Dig a trench around the entire perimeter that is 30 inches deep and a spade wide, keeping the soil to the side for backfilling later. The trench has to fully enclose the planting area with no gaps.
2. 2
   Install a 60-mil HDPE root barrier Drop 60-mil thick high-density polyethylene root barrier into the trench so that the top edge sticks up two inches above finished grade. The above-grade lip is essential, since underground stems that hit the barrier will run upward along it and can escape over a flush top. Overlap any seams by at least 12 inches and secure them with stainless bolts or a sealed clamp, then backfill the trench tightly so the barrier stands straight up.
3. 3
   Dig the planting hole twice as wide Inside the barrier, dig a hole twice as wide as the root ball but no deeper. Loosening soil out to the sides lets the new underground stems push into native ground quickly during establishment. Mix two or three shovelfuls of compost into the soil you removed if your ground is lean or sandy.
4. 4
   Set the plant level and backfill Lift the bamboo out of its nursery pot and set it in the hole so the top of the root ball sits flush with the surrounding soil, not buried. Backfill with the native soil you removed, firming gently around the sides to close large air pockets. Burying the base of the canes encourages rot at the crown, where moso is most vulnerable.
5. 5
   Water in deeply and mulch Soak the planting area until water pools and drains, then refill and soak again so moisture reaches the full depth of the root ball. Top the area inside the barrier with two to three inches of bark mulch, keeping the mulch four inches back from the canes. Mulch holds soil moisture through the first dry summer and feeds the soil as it breaks down.

Planting a division

A division taken from an established moso grove already has mature underground stems and roots, which gives a faster start than a young container plant. Take or buy divisions in early spring before new shoots emerge, with at least two healthy canes and a chunk of underground stem at least 12 inches long attached. Containment is just as critical here as with a container plant, so plan the root barrier before you dig.

1. 1
   Trench and install the root barrier first Before placing the division, dig a 30-inch-deep perimeter trench around the intended planting area and set 60-mil HDPE root barrier with two inches sticking above grade. Doing this first keeps the division from drying out while you trench, since divisions lose moisture fast through cut underground stems.
2. 2
   Trim the division and the canes Clean up the cut ends of the underground stem with a sharp pruner so they are not crushed or ragged. Cut the canes back to four to six feet tall if they came taller, which reduces the leaf area the smaller root system has to support during establishment. Soak the underground stem and roots in a bucket of water for 30 minutes before planting if they look at all dry.
3. 3
   Dig a wide shallow hole and set the division Dig a hole inside the barrier that is twice as wide as the division and just deep enough that the top of the underground stem sits two to three inches below the surface. Lay the division flat with the canes upright and the underground stem oriented across the planting area. Setting the underground stem too deep can rot it, and setting it on the surface dries it out.
4. 4
   Backfill, soak, and stake the canes Backfill with native soil mixed with a few shovelfuls of compost, firming gently to close air pockets without packing the soil hard. Water the area deeply until it settles, then drive a stake on the windward side of each cane and tie loosely. Staking prevents the canes from rocking before the new roots take hold, which is the most common cause of failed divisions.

The first year

The first year for a newly planted Moso Bamboo is almost entirely about what is happening underground. The plant is pushing underground stems out into the surrounding soil and storing energy for the burst of cane growth that comes in later years. You should expect very little dramatic top growth during the first season.

The most common new-grower mistake is reading the slow above-ground pace as failure and giving up, or pushing fertilizer to force growth. Heavy fertilizer applied year one burns the new fine roots and does not speed cane development. Water deeply once or twice a week, keep the mulch refreshed, and trust the process.

Healthy first-year growth looks like steady green leaves, no major yellowing beyond a normal spring leaf drop, and one or two short new shoots emerging from the soil in late spring or early summer. New shoots come up at the diameter they will keep, so do not panic when the first shoots are pencil-thin. The truly large timber canes come in years four through ten as the underground network matures.

What can go wrong

1. New shoots popping up outside the barrier

   An underground stem has escaped, usually by jumping a seam or finding a flush spot in the barrier top. Walk the perimeter and check for shoots beyond the barrier each spring, when underground stems are most active. Cut any escapees off at ground level with a sharp shovel as soon as you see them, then re-excavate the barrier section to find the gap and reseal it. Letting one season pass without checking can mean shoots fifteen feet beyond the planting by fall.

2. Yellow and dropping leaves in spring

   Bamboo drops a portion of its older leaves every spring as new growth pushes in. This looks alarming on a young plant because the relative loss is so visible, but it is normal and the plant will refoliate within a few weeks. Keep watering on the same schedule and resist the urge to feed or move the plant. If leaves yellow heavily outside of the spring window, check for waterlogged soil instead.

3. Buried cane base (slow crown rot)

   If the base of the canes ended up below the soil line during planting, or mulch piled up against them later, the crown stays wet and starts to rot. Gently pull soil and mulch back from the base of each cane until you can see the transition from cane to underground stem clearly. Keep mulch four inches back from the canes going forward. Crown rot caught early usually recovers, but a full-grown moso lost to crown rot is a long replanting project.

4. Canes leaning or rocking in wind

   A division or a tall container plant that was not staked can rock at the base before new roots anchor it. The rocking shears the fine new roots as they form, which slows establishment and sometimes kills the plant outright. Drive a stake on the windward side and tie loosely with a soft material that will not bite into the cane. Remove stakes after one full growing season.

5. Late frost damage on new shoots

   New shoots that push up before the last spring frost can be hit by cold and turn black or mushy at the tip. The shoot itself rarely recovers and should be cut off at ground level, but the plant pushes more shoots from the underground stems through early summer. Cover emerging shoots with frost cloth or an upturned bucket if a late frost is forecast within the first two springs.

6. Slow growth and thin canes in year one

   Moso puts almost all of its first-year energy into building the underground network, not into cane size. New shoots come up at the diameter they will keep their whole life, so pencil-thin shoots in year one are normal and not a failure. Cane diameter increases generation over generation as the plant matures, which is why timber-grade canes typically appear in years four through ten.

7. Brown leaf tips during a hot dry summer

   Drought stress is the most common cause in the first year, when the plant has not yet extended underground stems far enough to find moisture on its own. Water deeply once or twice a week through hot dry stretches and let the top inch of soil dry between sessions. Refresh the mulch ring to a three-inch depth if it has thinned, which slows evaporation and protects the shallow new roots.

8. Container-planted moso outgrows its pot fast

   A young moso in a pot smaller than 25 gallons will fill the container with underground stems within one or two seasons and start pushing roots out the drainage holes. Plan from the start to use a container at least 25 gallons with a sealed base, or a large planter sitting on a paved surface that blocks roots from escaping. Plan to divide and refresh the soil every two or three years, since a container moso that gets fully root-bound will dry out fast and decline.