Learn About Bamboo
First and foremost, keep your bamboo well watered. Bamboo likes plenty of deep watering – soaking down to at least 8-12 inches – and also good drainage. If you are keeping your plants in containers, or unable to transplant for a while, make sure the water is running out of the bottom of the pot each time you water. With ground plantings, a deep soaking less frequently is best, rather than a shallow watering every day.
You will need to keep a close eye on your bamboo for a while to determine how much and how often to water in your particular micro-climate, soil type and season. Occasionally, check moisture in the ground by digging down to a depth of at least 4 to to 8 inches. If the soil is dry at 4 inches, water is not getting to the bamboo roots adequately.
This is especially important during the first 2-3 months after transplanting. In fact, we recommend that you supplement automatic watering systems with a deep hose watering every day or two during the first few months. Also, in full sun, dry, windy or hot situations, it is ideal to mist or spray the foliage with water once a day for an initial transition period of 2-4 weeks. Regular overhead watering will reduce the amount of leaf drop during the transition and help your bamboo get established quickly. In very hot, dry climates you can continue misting year round if you like, humidity will almost always increase growth rate and ultimate height.
After the initial transition time, water deeply, then wait until the soil is just slightly damp – not wet nor bone dry – before watering again. At this point you can usually depend on a spray emitter irrigation system, using 2 to 4 high volume emitters per plant. (We do not recommend “drip” systems, as they do not emit a large enough volume of water and do not cover an area widely enough.)
As a rule of thumb, if the leaves are curling sideways (lengthwise) this means your bamboo is stressed and not getting enough water. If the leaves are drooping downward, your bamboo might be getting too much water and/or not enough drainage.
For a point of comparison, in our coastal West Sebastopol climate, we generally water potted plants 3 times a week in the summer, and more often if it’s really hot, and/or the plants are in full sun. Similarly, we sometimes water less than 3 times a week if the weather is cool and/or the plants are in full shade. Bamboo in the ground generally need less frequent watering here – once a week, sometimes twice a week is adequate – because the larger volume of soil stays moist and cool for longer periods. For plants that are root bound or have been recently transplanted, we water every day or two, depending upon weather and shade/sun.
During the winter months, our watering frequency here in West Sebastopol varies greatly, depending upon rainfall and other weather conditions such as wind and cold. When we have longish cold, dry spells, we water 1-2 times a week. Note that bamboo plants will do better in extreme cold when well watered. On the other hand, we can sometimes go for many weeks or even months without watering when it’s raining frequently and heavily.
Again, this information is meant as a point of reference only (we can often get 60 inches of rain here, and are heavily influenced by the cool ocean air). There is absolutely no substitute for paying attention to your bamboo plants, your micro-climate, and your day to day weather!