How to care for established bamboo plants

A customer from Riverview, Florida who purchased several Green Hedge clumping bamboos (Bambusa multiplex 'Silverstripe') emailed to say:

About 4 years ago I bought some bamboo from your lovely property. We love it and it did everything you said it would. It blocked a two story house that had been built behind us and provided a beautiful screen for our viewing pleasure. My question has to do with keeping the bamboo as a smaller clump to fit the area it is in. When new stalks come up do I dig it up or just cut it at ground level? Can I thin it a little from the middle by cutting stalks shorter or will they get new growth on the cut stalk like some plants do? And lastly, since this is such a prolific grower is it really necessary to feed the bamboo or does it need it to keep a green color? And what do you think is the best food for it?

By the way, this bamboo went through those horrible freezes we have had for the last two winters with flying colors. I couldn't be happier. When the rest of my plants and bushes were devastated the bamboo was our shining star.

A 6-year-old clump of Green Hedge bamboo

My response:
The best way to maintain a clumping bamboo once it has reached the size you want is to knock over new shoots when they appear around the perimeter of the clump.  Kicking or knocking over the young shoots stops that shoot from growing.  During the summer above-ground growing season, other new shoots may still appear but when they do, they can be knocked over as well. 

Another way to control the size of a clump is to cut back on watering and fertilizing once the circle of bamboo has gotten as big as you want it to be.  A mature clump of bamboo does well even without extra water and fertilizer. 

New shoots cannot be dug up and transplanted.  First of all, digging through a mature clump of bamboo is extremely difficult since the root system is so dense.  If you do manage to cut through with a reciprocal saw, ax or specially designed shovel, you would only want to cut out mature, fully leafed canes.  New shoots would have to grow up and leaf out before they can be divided off.

Any time a bamboo culm/cane is topped, it will not grow any taller.  It will, however, get leafier below where it has been cut.  Cutting out canes from the center of a clump provides a more open appearance.  Although new shoots sometimes come up in the middle, their tendency is to appear around the perimeter.

The fertilizer we like best is a 6-month time-release formula (18-6-8) high in nitrogen, which is what bamboos need for optimal growth.  We can send you a 1#, 3# or 6# package of fertilizer if you are interested.