Growing and Maintaining Bamboo

Growing bamboo successfully is a simple and rewarding task and can be accomplished in most situations. Please read the guide  below for an outline of the most important points.
Call us at 503-647-2700 or email bamboo@bamboogarden.com if you need assistance or advice for anything bamboo related :  Members of our experienced staff are available do consultations, installations, maintenance, bamboo removal, and barrier installations in and around the Portland area.
Placement and Spacing Although most people have a place in mind as to where they want to plant their bamboo, one should keep in mind that most large bamboos (Phyllostachys) do best with 5 or more hours of direct sunlight. They must be given ample water, fertilizer, and protection from competitive weeds. They will benefit from a windscreen and light shade when first planted as well. This is especially true of smaller plants. Fargesias, Thamnocalamus and Sasas do well with light to moderate shade. In fact the Fargesias and most Thamnocalamus are happier with some shade during the hottest part of the day. Fargesia and Thamnocalamus are the hardiest of the clump type bamboos. They can be planted without fear of spreading. See this link for a photo of the Clumping type rhizome. Most other hardy bamboos can spread by their underground rhizomes and this must be taken into account when planting them. We recommend annual root pruning as the first option for control. Also, barrier of 60 mil by 30 inch deep, HDPE (high density polyethylene) can be used for rhizome control. For helpful information and photographs about controlling and maintaining bamboo see: control methods Bamboo should be spaced 3 to 5 feet apart to form a dense screen. The faster spreading types can be planted farther apart, if you are willing to wait a little longer for the screen to fill out. Starting from a small size, most bamboos will reach mature height within five or six years. As a very general rule, Clumping bamboo gain about 1-2 feet of height per year, and the Running types grow about 3-5 feet per year, and spread outward at the same rate. Height and spread rate is variable depending on the species and climate. If as instantaneous screen is desired, most bamboo will not suffer from being planted nearly back to back.  Feel free to contact us to discuss details about your project. Planting Your New Bamboos Most bamboos are happiest in a moderately acidic loamy soil. If your soil is very heavy you can add organic material. It can be dug into the soil where the bamboo is to be planted, but the easiest thing is to mulch very heavily and let the earthworms do the work. Spread two or more inches of mulch in the area around the bamboo, and where you want the bamboo to grow. Bamboo is a forest plant and does best if a mulch is kept over the roots and rhizomes. It is best not to rake or sweep up the bamboo leaves from under the plant, as they keep the soil soft, and moist, and recycle silica and other natural chemicals necessary to the bamboo. A low-growing shade-tolerant groundcover plant that will allow the leaves to fall through to form a mulch without being visible will work if you find the dry leaf mulch objectionable. Almost any organic material is a good mulch. Grass is one of the best, as it is high in nitrogen and silica. Home made or commercial compost is great. Hay is a good mulch too but hay and manure are often a source of weed seeds, so that can be a problem. Any kind of manure is good, if it isn't too hot. Limited amounts of very hot manures like chicken are OK if used with care. At our nursery we use a large amount of chipped trees from tree pruning services. This can harbor pathogens that can affect some trees or shrubs, but the bamboo loves it. Planting small starts When planting smaller size starts (1 or 2 gallon),  it is important to protect them from overexposure to the hot sun, especially Fargesias and other shade loving bamboo. This is most important in the summer and when the chosen site has concrete, or near a wall that could reflect light and heat on to the plant. In such a potentially hot spot, it may be best to use a larger more well established bamboo (5 gallon or larger), and/or plant in the spring or fall.. Timing and winter protection Bamboos can be planted at any time of the year in areas with mild climates such as we have in the maritime Pacific Northwest. In colder parts of the world they should be planted outdoors early enough to become established and to harden off sufficiently to survive their first winter. If the bamboo is planted late in the year, one should mulch the plant heavily and provide extra protection from any cold and drying winds. In colder climates where bamboos may be marginal, successful growers usually protect their bamboos through the winter with a heavy mulch. Even in very cold climates in an established bamboo grove with a heavy layer of bamboo leaves covering the ground, the soil will be soft and friable during periods when the surrounding soils are frozen hard and deep. In very hot climates, where summers routinely get over 100 degrees, it is best to wait until Fall or Spring to plant bamboo, unless it can be given a shady area or some kind of protection from the sun. Controlling the spread of bamboo See this link for an overview of control methods We recommend annual root pruning as the first option for control. Also, barrier of 60 mil thickness by 30 inch deep, HDPE (high density polyethylene) can be used for rhizome control. . If you plan to install a barrier to control the spread of running bamboos, it is important to install it properly to ensure its effectiveness. In other than very light soils, the bamboo rhizomes are usually in the top few inches of soil. However when the rhizome encounters an obstruction it will turn, and sometimes it will go down. It is important to avoid loose soil or air pockets next to the barrier or the bamboo may go deeper than you want and perhaps go under the barrier. When filling the hole after placing the barrier, tightly compact the soil next to the barrier. Any soil amendments must be added only in the top foot or so. You mustn't encourage deep rhizome growth if you want to contain the bamboo. If the bamboo planting can be surrounded by a shallow trench 8 to 10 inches deep, this can be a cheaper and easier method to control its spread. See link for pruning trench technique. You just need to check a couple of times in the late summer and fall to see if any rhizomes have tried to cross the trench, and cut them off. Checking for spreading rhizomes is very important. It must be done each fall, whether you are using barrier or a trench. King of Spades ™ We now sell the King of Spades root cutting shovel (13" blade, long handle): an excellent, professional grade tool, for cutting rhizomes and digging bamboo.  We have been using this shovel for many years at the nursery, highly recommended.  $105.00 Growing bamboo in containers  Many people ask us if bamboo can be grown in containers. The short answer is yes. However, there are a few key points to consider. Every two to five years they will need to be repotted or divided. The Black Bamboo on the right, has burst through the thin plastic nursery container (click on photo for larger image). Repotting or dividing is best done in the springtime. If over grown and root bound, most bamboos can escape or even break their confinement. Tight spaces, including pots and barriers, will restrict the culm size. For example, Phyllostachys nigra can grow over 30 feet tall in the ground but will often not top 15 feet when grown in a container. The larger the space, the larger bamboo will grow. Bamboo in containers require more care because they are much more susceptible to environmental stress. They are more sensitive to heat and cold, strong winds tip them over, and the restricted root space allows them to dehydrate quickly. A well established bamboo in a container should be watered 3 to 5 times per week during the summer, ensuring that the pot drains well. In containers bamboos, especially those that are not well adapted to hot sun, require more care in placement as they can be damaged if the pot overheats. During winter, container bamboos are susceptible to freezing and if not protected may die. Bamboo in containers is not nearly as hardy as the same bamboo would be in the ground. Bamboo can be a fine container plant if its needs are met. We recommend using wood planters or containers that have some insulation for the root mass.  If you use metal feed troughs, make sure they have adequate drainage and use only very hardy plants. We sell 30" cedar planters lined with rhizome barrier which provides a decent home for most bamboos for about 3-5 years before they need to be transplanted.     We sell decorative, 30 inch square cedar planters for $85 each. Staking tall plants When planting bamboo over 15 feet tall, it may need to be staked or guyed for the first year of growth or until well anchored by their root mass. This will prevent strong wind from uprooting them, or damaging new shoots and culms. Tall bamboo plants are best guyed with a rope tied to the same point on the culms, anywhere from about one third to halfway up the culm. Use three or four guy lines depending upon how much wind you expect. We recommend four ropes, one on each point of the compass. Drive two foot stakes one and one half feet into the ground at least 6 feet from the bamboo. Wood and bamboo stakes work well. If supporting very large bamboo, metal stakes are recommended. A useful method for supporting long, tall screens is to put a sturdy post at each end of the screen and run a strong line between the two posts. Each bamboo can be loosely tied off the main line. A fence can serve the same purpose for bamboo about 15 feet tall. Yellowing and falling leaves. In the spring there is considerable yellowing of the leaves, followed by leaf drop. This is natural and should not cause concern, as bamboos are evergreen and naturally renew their leaves in the spring. They should loose their leaves gradually as they are replaced by fresh new ones. In the spring on a healthy bamboo there should be a mixture of green leaves, yellow leaves and newly unfurling leaves. Water Newly planted bamboos need frequent and liberal watering. Twice a week during mild weather, and perhaps even daily during hot or windy weather, give your bamboo a good watering. Make sure that each plant under 5 gallon pot size gets at least ½ gallon of water. For plants over 5 gallon size more than 1 gallon is advised. Once a bamboo has reached the desired size, it can survive with much less irrigation. But until then you must water and fertilize copiously to achieve optimum growth. Lack of sufficient water especially during hot or windy weather is the leading cause of failure or poor growth of new bamboo plants. Watering newly planted bamboos every day, or for longer than a few minutes can cause excess leaf drop. Well-established bamboos are rather tolerant of flooding, but newly planted bamboos can suffer from too much as well as too little water. Fertilizing Bamboo if planted in a suitable site (full sun for most, partial shade for some) and given ample water can grow and eventually thrive. But if you want a healthy attractive vigorous plant, you must fertilize. We use a lawn fertilizer it is high in nitrogen. 21-5-6 is the formula. Organic fertilizer high in nitrogen is even better, though it is more expensive. Provide a 2-3 inch layer of compost or aged manure around the base of the plant, and outward where you want it to spread, for a natural source of plant food. Pruning Bamboo
Maintenance pruning for large running bamboo Bamboo, like other plants, requires some pruning to maintain its attractiveness. Individual bamboo culms live about 10-15 years, but a full grove producing many new canes each year can live for several decades. Once each year you should remove older, unattractive culms and cut off any dead or unattractive branches. You can prune most bamboo without fear of damaging it. Just trim so it looks attractive. Make cuts just above a node, so as not to leave a stub that will die back and look unsightly. If you cut back the top, you may want to also shorten some of the side branches so the plant will look more balanced, not leaving long branches at the top. See this link for photos and descriptions of the thinning process of a bamboo grove:	Thinning Clumping Bamboo Clumping Bamboo can be pruned to maintain upright growth, or thinned to maintain an airy appearance. If the plant gets too wide, just clip some of the outer canes back to ground level.  See this page for a photo illustrated guide to pruning clumping bamboo.
Topiary Bamboo may be trimmed in topiary fashion. You may top the culms, remove some lower branches, and shorten some side branches and remove others. Any culms or branches cut do not grow back longer but only grow more leaves. The photo on the right is a Phyllostachys aureosulcata 'Aureocaulis', pruned to about 6 feet tall, highlighting the bright yellow canes and dark green foliage. It is a very unusual design, but it works in this space. Click on photo for larger image.   For Screens or Hedges Bamboo may also be cut to form a hedge as one might do with boxwood or other traditional hedge plants if one wishes. This is best done after the new culms grow to full height in the spring or summer. (Most of the new growth on a bamboo plant happens at the same time of the year, usually late spring or early summer for temperate bamboos.) There should need be only one major pruning, with only minor touch up at other times of the year. If you want to control the size or height of your bamboo, and retain the natural look of the bamboo, this can be done by removing new shoots that are significantly larger in diameter than the culms that are the desired height. These shoots will be replaced by smaller diameter culms that will not grow so tall. This can be safely done with a plant that has been well established, not a newly planted bamboo. Legging up For display of colorful bamboos such as Phyllostachys nigra, Phyllostachys bambusoides ‘Castillonis’ and Phyllostachys vivax ‘Aureocaulis’ you can enhance the beauty by removing smaller culms and cutting off lower branches so that the beauty of the culms is visible. Groundcover Bamboos For dwarf bamboo we recommend cutting it to the ground each spring, so that the plant is rejuvenated. It will look much nicer when the new growth emerges, and it will be kept shorter and more dense. Dwarf bamboos are also often trimmed later in the season to keep them shorter and more uniform in height. In very cold climates such as zones 4 or 5 dwarf bamboos may have their tops freeze back in the winter and still be good for landscaping. Just mow them as you should do in places where they don’t freeze back.  (click on link) Bamboo inquiries: General questions and answers from our customers. Lots of good information about growing bamboo! Bamboo Pests see link for information about bamboo pests.   It looks like bamboo, but it ain't  see Imposters: Not bamboos at all also see From Terra Viridis Nursery Plants Commonly Mistaken for Bamboo

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