Bamboo Yellowing and Dead Shoots

Q. Several of my bamboo shoots died completely and now they are all starting to yellow and have a white film on them. Any suggestions?

White film on the culms or stems of bamboo probably a wax "bloom".

A. You didn’t say which bamboo it is, but I assume it’s one of the bamboo tolerant of our winter temperatures. The so-called “running bamboo” rather than the clumping types represent those that tolerate our climate better.

            The white film is sometimes called a “bloom” of wax on the outside of the stem and is normal. If these are instead white “fuzziness” in patches and appear to be a problem, then you might be looking at mealybugs. But I think this white “film” has more to do with the naturally occurring wax produced by many plants rather than a pest problem.

             Yellowing can be caused from water not draining from the soil around the roots and suffocating them because of poor drainage or watering too often. You may be thinking that this plant needs water all the time, which it doesn’t. The soil needs to be kept to moist for good growth but let the soil “breathe” so that the roots and rhizomes can get air.

            Invest $10 in a soil moisture meter for house plants. As long as the soil is somewhat soft, push the probe slowly into the soil and get a soil moisture reading at the 4 to 6 inch depth. I would not irrigate until the meter on this gauge reads approximately “6” at this depth in 3 different locations. On these gauges, “10” is sopping wet and the number 1 is totally dry.

            The yellowing could be a soil alkalinity problem but I think instead it is probably poor drainage. When planting bamboo, amend the soil with compost at the time of planting and cover the soil around the plant, out to a distance of  2 to 3 feet, with woodchips. If drainage is a big problem even after amending the soil, plant it on a mound.