Cold-Hardy Bamboo Varieties for Zones 5 to 7

Zones 5 to 7 in context

On the USDA map, average annual minimum temperatures run roughly from -20°F to -10°F in zone 5, -10°F to 0°F in zone 6, and 0°F to 10°F in zone 7. Plenty of bamboo can handle that, but you need to pick carefully. Tropical clumping bamboos, which make up much of what is sold in warm regions, are not suited to these zones. Hardy options fall into three groups: cold-hardy clumpers, hardy runners and groundcover bamboos. For ornamental grasses suited to the same climates, see hardy ornamental grasses for zones 5 and 6 and the best grasses for zones 7 and 8.

Hardiness figures are guides, not guarantees. Young plants, plants in pots, windy sites and late planting all lower real-world hardiness. Always check the rating on the label, and confirm with a nursery that grows bamboo in a similar climate. For the broader picture, see where bamboo will grow.

Cold-hardy clumping bamboos

Most clumping bamboos are tender, but Fargesia is the notable exception. Growers describe Fargesia and Thamnocalamus as the hardiest clumping types, and they can be planted without fear of spreading.

• Fargesia species (including F. rufa, F. murielae, F. nitida and F. robusta among others). One retailer lists Fargesia rufa for zones 5a to 8b, at about 6 to 10 feet tall in clumps 6 to 8 feet wide. Another source puts the same species at around 0°F and colder. Different species and cultivars vary, so check each one.
• Borinda and Thamnocalamus. Offered by some nurseries as hardy clumpers, with sizes and hardiness varying by species.

Things to know about cold-hardy clumpers:

• They like shade, especially in the afternoon. Many do best with light to moderate shade, and some need relief from hot afternoon sun outside cool, coastal regions.
• They dislike hot, humid summers. Growers note that Fargesia grown in hot southern climates may never be as large or healthy as those in cooler regions.
• They stay modest in size. Typical heights are around 10 to 15 feet for many, and canes rarely exceed about an inch in diameter.
• They make dense screens with fine, arching foliage. See planting a bamboo privacy screen.
• They are container-friendly, though pots are less hardy than ground. See growing bamboo in pots and containers.

Cold-hardy running bamboos

Many running bamboos tolerate colder winters than most clumpers, which is why Phyllostachys is common in zones 5 to 7. A few examples with approximate hardiness figures from one nursery’s information:

• Phyllostachys bissetii: hardy to about -15°F, with dark green canes, often 20 to 35 feet in warm climates.
• Phyllostachys aurea (golden bamboo): about -5°F, yellowish canes, a popular but vigorous runner.
• Phyllostachys nigra (black bamboo): about 0°F, with canes that darken with age.
• Phyllostachys aureosulcata (yellow groove bamboo): widely grown for cold tolerance and upright form, and also suitable for large containers.
• Phyllostachys decora: one nursery gives about 15 to 17 feet in zone 5, with dieback in a hard winter, and says it is not recommended for zone 4.

These are figures from commercial sources, and different growers give slightly different numbers. Treat them as a starting point, and check with a local nursery.

Things to know about hardy runners:

• They must be contained. Plan a barrier, pot or root-pruning routine from the start. See how to install a bamboo rhizome barrier and running vs clumping bamboo.
• Height drops as the zone gets colder. One grower suggests subtracting about 3 to 5 feet for each zone colder than their listed zone, for Phyllostachys, and about a foot per zone for shorter bamboos.
• They are the only route to thick canes in cold areas. Cold-hardy clumpers rarely make canes much larger than an inch across.
• Many stay evergreen through zone 7 and often zone 6, with some to zone 5, although leaves may be damaged in severe winters.

Groundcover bamboos

Low running bamboos such as Sasa and Pleioblastus are used as groundcovers and under taller plants. In cold climates (zones 4 to 6), they can be deciduous or die back to ground level, and they usually shoot again in spring if mulched well through winter. They spread, so containment matters, and they can be cut to the ground in late winter to renew them. See pruning bamboo.

What to expect from bamboo in a cold climate

• Slower growth and shorter plants than the same species in a warm climate.
• Some winter damage. Leaf browning is common after harsh, windy winters, and some canes may die back. Wait until spring before cutting, because plants often recover.
• A longer wait for screening. See how long it takes bamboo to grow.
• Zone 4 is usually marginal. Some bamboos hardy to zone 5 may be root hardy in zone 4, and growers sometimes suggest pots that can be moved indoors for winter. In zones 3 and 4, cold-hardy ornamental grasses are a more dependable choice for height and texture.

Planting and winter protection

• Plant in spring in colder zones. This gives roots time to establish before winter.
• Mulch heavily, especially the first winters, and in marginal sites.
• Shelter from wind. A fence, wall or evergreen hedge on the windward side helps.
• Water in dry spells, including in winter. Bamboo generally copes better with cold when well watered.
• Choose a protected microclimate, such as the south or east side of a building, but keep shade-lovers out of hot reflected sun.
• Use bigger plants. Large, established plants tend to be hardier than small ones.

For the general planting method, see growing bamboo in your yard.

Choosing between them

If you are unsure, ask a nursery that sells bamboo in your region which species have survived local winters, and start with a clumping type. Is bamboo a good plant to have in your yard? can also help you decide whether it is right for your garden.