Seasonal Bamboo Care Tips

THINNING CULMS IN HEDGE. Bamboos with a running habit look best when the culms (canes) are spaced 4–6 inches apart. Use a tree pruning or bamboo saw as close to the ground as possible. The stubs will turn hard later. This may be done anytime, though not the best in Spring when new culms are popping up. See our web page Care and Maintenance for more details. The clump-rhizome bamboos may be thinned, but are beautiful and perfectly happy being close together.

RHIZOME MANAGEMENT. Since this year’s rhizomes finish traveling in October or early November, now is a great time to do your annual below-ground pruning. Depending on your soil, you’ll need to cut 6 inches down (sometimes they may be deeper if they run into a barrier. See our web page Care and Maintenance for details.
If you are using a rhizome barrier, it is wise to check along the inside rim to make sure rhizomes are not building up against the barrier and want an escape route—over or under. They may be 12–20 inches deep right inside the barrier. Areas away from the barrier are usually in the 6–12 inch depth. If you miss any , you’ll know where they traveled when the new culms (canes) pop up in spring. Keep in mind that bamboo is a GIANT GRASS and needs edging just like a lawn. Newly grown rhizomes are tender their first year so annual pruning is better before they harden.
Caution: There is a myth that you can control the spread of bamboo by mowing or cutting down the culms. This does not work when the rhizomes are still attached to the mother plant. Even when detached they may still have enough root mass and maturity to produce new culms.

MAINTENANCE HELP IS AVAILABLE. For help thinning culms or rhizome pruning, call us to request a Bamboo Maintenance estimate. We also assist with planting and moving bamboo or dividing from containers.

FALL & WATERING SCHEDULE. In the Pacific Northwest there is no definitive schedule for watering during the cold season. When there has been only light rain for a week, check your soil down about 6 inches. Water if it is dry. During the gray days, all plants use less water. Bamboo in containers may need periodic watering, since the rain often runs off leaves and misses the pot. If you notice leaves curling upward, it is most often due to dry soil. A stressed plant will have a harder time during a severe cold spell. If it has been thirsty for a while, water lightly and more frequently. The uptake of water will be slower than in summer so take care not to flood the plant. Bamboo does not like sitting in boggy soil.

BAMBOO IN A CONTAINER. If your bamboo is rootbound in the pot, now is a good time to move it to a large container or to divide it into two containers. If you do divide, simply slice off a third or more as if you were cutting a cake. Then use a root stimulator to encourage the growth of the tiny feeder roots. (Note these are like short strings attached to the rhizomes.)

Winter Hours

Starting October 31st we change to 4 p.m. closing. This prevents wandering with flashlights. We have no exterior lighting.

Winter Protection

Forecasters anticipate a mild winter, though caution that there may be some very cold days. Prepare ahead!

FOR IN THE GROUND BAMBOOS. Add 2–3 inches of mulch around your planting bed. See Mulching on our web page Care and Maintenance. In addition to winter protection the organic matter keeps down weeds and creates healthier plants.

BAMBOO IN CONTAINERS. Above-ground bamboos, even those hardy to minus 20º F, are susceptible to rhizomes freezing if they are in pots smaller than 20 inches diameter and 14 inches deep. Rootbound plants in any size containerare also more at risk due to lack of soil for protection. If possible bring pots closer to your house or outbuildings, awayfrom cold wind exposure and group together. For smaller pots nestle them in mulch in the garden or put the pot within a 2–3 inch larger pot. Insert compost or leaf mulch between the pots for insulation. If you have any plants that are hardy to only 10º F, move them inside or to a greenhouse, unless you live in a warmer microclimate like near water. Do this right away to prevent shock from temperature changes.

Images from Bamboo Gardens

Photos by Joseph Matthews

Josh Dawson, our Bamboo Maintenance Specialist, controls rhizomes on Phyllostachys vivax—our tallest, most impressive culm-size bamboo.

Granite Coin Basin

Ornamental Grass Seasonal Care

Do you have ornamental grasses in your garden? If so, you may want to hold off “putting them to bed” for the winter. Both evergreen and perennial grasses can help add that elusive fourth season to your garden. Evergreen grasses such as the charming Ice Dance (a Carex morrowii cultivar) are stellar year-round performers.

Perennial favorites such as the feather reed grasses (Calamagrostis x acutiflora) and the Japanese Silver grasses (Miscanthus species) have frothy upright plumes that can last all winter given minimal protection. Here in our garden, customers comment on how the “flowers” seem to glow when the sun breaks through the autumn fogs. Unless your grass becomes too damaged by winter rains or the occasional heavy snow, let them remain to enjoy the beautiful dried plumes until February or March. At that time they can be cut down—more on that in our Spring newsletter.

Some grasses, like the fountain grasses (Pennisetum species) and tufted hair grasses (Deschampsia species) and even the fescues (Festuca species) can last through a mild winter with little maintenance. So just remove any damaged parts and comb out the loose material to discourage rot. If you apply an organic mulch, be sure to keep it a few inches from the base of the plant for that very same reason—avoiding rot. Grasses that prefer warm and dry climates, such as the fescues, will look better if you give them a gravel mulch during the wet months. Technically you can divide ornamental grasses at any time of year, but your plant will reward you if you wait.

If you plan on dividing your established grasses, experts say it’s best done while they’re actively growing (producing foliage). This yields better growth and overall health. However, given a mild winter, you may divide ornamental grasses any time of the year.

If you want to see grasses in action before testing them in your own garden, come take a look at our display gardens in fall and winter. There are also many places in the area with good four-season displays. The Paul Allen building, at 5th and Weller in downtown Seattle, has eye-catching plantings with grasses and bamboos. The University of Washington’s fisheries building and the Redmond Library have well-planned gardens with grasses. For those on the south end, check out the King County Regional Library in Federal Way at different times of year to see how their grass display changes with the seasons.

Bamboo Fence Installation
Did you see us at the Home Show in October? We showcased our bamboo fences with our plants. We like to use 4 x 4 posts painted black or dark brown to set them off. Visit our nursery for “How to Install” information.

For Winter Reading. . .
Timber Press Pocket Guide to Ornamental Grasses by Rick Darke, available at Bamboo Gardens is an amazingly thorough reference book in a small format. The author’s experience is evident throough concise, easy-to-read descriptions. He paints a clear picture of each plant and doesn’t shy away from explaining an individual grass’ weaknesses and strengths. In addition to bamboo-oriented books, we also now have Grasses by Nancy Ondra and Gardening with Grasses by Michael King and Piet Oudolf in stock.

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