As those of us in the Northern Hemisphere head into the Summer, the days will be getting hotter and we'll be hitting our hottest months in July through August.  Here are just some of the way in which climate affects your bamboo.  Today we're discussing the growth habit of temperate bamboo during the summer months.

Temperate ("running") species are about to go dormant--above the ground.  Their shooting season is over and as temperatures increase, further culm growth halts.  On culms whose internodes have fully extended during this growing season, the protective sheath has fallen off, allowing branch buds to extend and in some cases leaf out.  (That internodes/branches/leaves that haven't fully extended will resume their activities next spring.)  It's interesting to note that while the plant is dormant above ground, the rhizome below ground will begin an active season of growth in the warmest months.  This is when your bamboo grove will significantly increase its area on your property.  If containing or controlling the spread of your "running" species (characterized by a leptomorphis rhizome that can spread up to 30 feet in a single growing season!) then this is a great time of year to pursue containment strategies.  You might choose to remove rhizomes, which is labor intensive due to the complex network of connected rhizomes, some of which have lignified into something harder than wood, and it will require a great deal of upheaval to your landscape.  An alternative solution is to dig a trench and install the HDPE rhizome barrier (60 mil thick, 24-30" tall, depending on your grade).  Or if you are comfortable with a topical-only treatment, you'll see no more growth from your temperate bamboo this year and you can just remove whichever culms you like.  We recommend the following process: remove 2-3" of the soil around each culm, use a flush-cut hand-saw to remove each culm, and replace the soil.  This will eliminate unsightly "stumps" from your landscape and prevent people from tripping/hurting themselves.  

Next blog will focus on how the heat affects your sub-tropical and tropical "clumping" (non-invasive) bamboo.