Our bamboo clump is doing something similar. It is only 6 years old, but this year has put up shoots that are twice as thick as anything before. And they seem to grow daily. My theory is all the rain we've had this spring.

jb

Yes: it is simply doing well. Early hot weather might have helped, other kinds of plants also seem to have been energized this year. Another dramatic example, in addition to your bamboo: a purpleleaf plum cultivar planted in many locations in Seattle, is fruiting here for the first time since an expert in these plants began monitoring this variety in the 1980s. Many plants we cultivate in our gardens, including Phyllostachys spp., are native to or were developed in hotter climates than hours. Even right here in the United States most other areas have much warmer growing seasons. Western Washingtonians merely have to drive down to Vancouver-Portland area or over the Cascade Mountains to encounter markedly more assertive summer conditions.

That's easy. Last year's anomalously wet August and September enabled the bamboo to make extensive rhizome and root growth. They grow most of their rhizomes in late summer and fall, and many running bamboos behave as clumpers in our climate because there is not available soil moisture for them at the time they like to run.

Thanks for the input. Ian's answer is the scary one. This was sold as a clumper and has behaved that way for all of these years. If it is truly a runner then I have a major problem on my hands as it is now within 15 feet of my vegetable garden. Any suggestions? jwww

Black bamboo is sometimes sold as a clumper; people don't realize that the 'clumping' effect is just a lack of summer water on what is normally a running bamboo. Well first of all don't be too scared because it will not spread as much when we have our usual dry summers in the future. Where you want to curb it, dig out a 6" deep trench around it and cut of any rhizomes that cross its path... also pull out the pieces that are on the 'wrong' side of the trench. It helps to have an old pair of pruners to cut the rhizomes with, but if your shovel is sharp enough you can cut them that way. If you keep the trench open you can always just cut off the rhizomes as soon as you see them poke into the trench, as long as the side is vertical. This is an easy way to control black bamboo and other Phyllostachys since their rhizomes are always very shallow.... if you don't mind the idea of a trench around your plant. (And it is actually VERY easy once you have just dug the trench and cut the rhizomes once... since the rhizome growing tips are much softer and easier to break than established hardened rhizomes.)

Ian.....thanks for the additional advice....this is my one and only bamboo.....jwww

My P. nigra black bamboo ran from the start, but it was contained to a 21 x 3 foot bed structure. Now I see the neighbor across the street has planted some in open ground!

How easy is it to identify a bamboo? What should I take to a nursery if I want mine identified? Leaves, juvenile cane, mature cane? jwww

Mature canes. But: if it is all black or nearly so, it is Phyllostachys nigra.

Dear Judy,

This is a fun post.

Running bamboo! I say count your blessings. If you bring it to a local plant swap you will be amazed how highly desired it is.

And truly, the trench idea works for containing it. They even sell something called a bamboo slammer, which is basically an axe head welded onto a pipe, like a sod cutter or ice chopper, which allows a bamboo grower to chop down around the clump periodically during the running season. If you cut those runners when they are immature, they die underground. Once they have set roots, if you cut them, they become independent plants.

The best time to dig and divide your new clumps is in winter, Jan-mid March.

If you lived in Seattle, I'd say bring it to the Redmond Green Elephant Plant Swap. But surely there are swaps in the Portland area to which you could bring it.

BTW all my bamboos are shooting up bigger and taller than ever this year as well. It's amazing to show it to people and watch the daily growth.

Have fun with this. It's not "invasive" and "running" it's just "robust" "vigorous" and "carefree".

FireVicar

The only certain way to ID some bamboos is with samples of the canes, leaves and photos of new shoots.... fortunately black is easy because if the 1 year old and older canes are black it can only be one thing, Phyllostachys nigra. The only other species with black canes are tropical clumpers that will not survive here.

Great post.
Our nigra bamboo has starts 2+ the times of the rest of the clump also, reaching upwards of the 2nd story of the house. Our Nigra is contained with bamboo barrier.
Other bamboo we have uncontained [chino] has been running a muck. I have been digging it out all over the front garden. Exhausting.

On the other hand, a contained 'spectabalis' has not sprouted at all. Very unusual. What's up with that?
Thanks.
Jen

I can't wait for my black bamboo to start running! I got mine from the green elephant trade March 5th, and within days of planting it a new shoot came up, in all one clump got 4 new shoots, and the other 2 shoots. The new ones are all bushy and very healthy. Like everyone told you, a little work and you can keep the bamboo where you want to. I'll have to take a picture and post it over at the picture forum soon, now that we have a new digital camera that is taking great pictures.

K

One thing I found with my P. nigra was that a 15 or 20mph gust would snap some of them over when they were full-height sprouts not yet leafed out. The golden or arrow bamboo was not affected by the wind.