Bamboo Planting and Care
Placement – 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 grow quicker and do their best in full sun. 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. Most other hardy bamboos can spread by their underground rhizomes and this must be taken into account when planting them. We recommend a barrier material 60-80 mil in thickness by 30-36 inch deep of HDPE (high density polyethylene) to control their spread.
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 ground cover 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. You can also use chipped trees from tree pruning services. This can harbor pathogens that can affect some trees or shrubs, but the bamboo loves it.
Timing and Winter Protection – Bamboos can be planted at any time of the year in areas with mild climates such as 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.
Controlling the Spread of Bamboo – If you plan to install a barrier to control the spread of running bamboos, it is important to install it properly to insure its effectiveness. We recommend for most situations a barrier of 30 inches deep. 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. 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. This check for spreading rhizomes is easy, but very important. It must be done each fall, whether you are using barrier or a trench.
Staking Tall Plants – When planting very tall and slender bamboos, they may need to be staked (actually, guyed is a better term). This will prevent wind from uprooting them, or damaging newly formed roots. Tall bamboo plants are best guyed with a rope tied to the culms up about 2/3rds the way up, and to short stakes on 3 or 4 sides of the plant at a sufficient distance to give the strength needed to prevent the wind from uprooting the stakes.
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 lose 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 more often, 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 a 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.
[Source: Ned Jaquith]