Bamboo offers a unique, fast-growing option for creating screens and adding a tropical aesthetic to the garden. Successful outdoor planting requires specific planning to manage its vigorous nature and prevent unwanted spread. This guide details the process for establishing bamboo outdoors while ensuring it remains contained.
Choosing the Right Bamboo Variety and Location
The most important decision is selecting between clumping bamboo (pachymorph) or running bamboo (leptomorph). Clumping bamboo has short, tight rhizomes, expanding the clump only slightly each year, making it non-invasive and easier to manage. Running bamboo spreads aggressively via long, horizontal rhizomes, requiring mandatory containment measures.
Running bamboo is preferred for fast-growing privacy screens but requires a barrier if planted near property lines or structures. Clumping varieties are suitable for specimen plantings and dense, contained accents.
Bamboo varieties have different light requirements that guide placement. Most running species (Phyllostachys) prefer full sun, while understory genera (Pseudosasa and Sasa) thrive in partial shade. Check the plant’s hardiness zone rating to ensure it survives local winter temperatures.
Essential Site Preparation and Containment
Successful cultivation depends on proper soil and effective spread prevention. Bamboo prefers well-drained, fertile soil rich in organic matter, with a slightly acidic pH between 5.5 and 6.5. Heavy clay soil should be amended with compost, grit, or sand to improve aeration and drainage, preventing root rot.
For running bamboo, containment requires installing a high-density polyethylene (HDPE) rhizome barrier, typically 60 to 80 mil thick. Install the barrier in a vertical trench 28 to 34 inches deep, ensuring the top two inches remain above the soil line. This exposed lip prevents rhizomes from growing upward and jumping the barrier.
The barrier seams must overlap by at least 12 inches and be sealed with specialized tape. Backfill the trench with firmly compacted soil to prevent voids. The barrier must be installed vertically, not slanted, to deflect rhizomes downward and encourage growth along the plastic surface.
Step-by-Step Planting Guide
Once the site is prepared, dig a planting hole two to three times wider than the root ball but no deeper. Bamboo has shallow roots, with most of the root mass developing in the top 12 to 20 inches of soil.
Carefully remove the bamboo from its container, and if the roots are tightly bound, gently loosen the outer layer by hand. Place the plant so the top of the root ball is level with, or slightly above, the surrounding soil grade.
Backfill the hole with the amended soil mixture, tamping gently to eliminate air pockets. Finally, create a small, raised ring of soil around the perimeter to form a watering basin, directing water straight to the root zone.
Immediate Post-Planting Care
The first few weeks are crucial for root establishment, requiring consistent deep watering. Immediately saturate the soil thoroughly to settle the backfill. For the first month, water daily or whenever the leaves curl lengthwise, indicating dehydration.
Apply a two to four-inch layer of organic mulch, such as wood chips, straw, or compost, around the newly planted bamboo, keeping it a few inches away from the culms. Mulch helps regulate soil temperature, reduces water evaporation, and suppresses competing weeds.
New bamboo benefits from a balanced, slow-release fertilizer, but wait until the plant shows visible new growth. A high-nitrogen fertilizer supports the initial establishment phase. Avoid using “weed and feed” products, as the herbicides can harm the bamboo.