need help understanding growth habits!

[joe lajeunesse]

i just got into bamboo and dont really understand the growth habits. I know there are many varieties but I see pictures of the same varieties where some of the pictures are 20' culms with branches only at the top and others of the same variety are bushy with branches from the bottom up. I dont really understand this. Do you have to constantly thin out the older culms to maintain a smaller bushy plant? To further explain i have included two pictures of golden beauty that are for sale on craigslist. I believe the outdoor picture is what they are selling and the indoor picture is just a random picture. I guess I am asking this because if I were to buy them I want to know how to keep it looking like the one in the indoor picture. Does that make any sense?

[Mike McG]

... I guess I am asking this because if I were to buy them I want to know how to keep it looking like the one in the indoor picture. Does that make any sense?

If they are the same species, and they probably are, the larger plants look the way the mature plants will look grown in the ground and the smaller potted plant is probably a more recent division. The potted plant was possibly being grown outside and only brought inside for the picture. The lack of lower branching can be a characteristic of the species or of shading by the upper branches, especially in a thick grove. Some people like the look of exposed culms and will prune the lower branches. It can take quite a few years for bamboo to acquire a mature form unless the environment is well matched to the plants needs. In some areas a certain species will never obtain a mature form because of cold, heat, drought or a number of other factors.

Although you can prune or cull certain shoots, it is easier to select a species that matches the form you desire and that will grow in your area. A word of caution depending where you are in Central NJ, is this bamboo growing locally? If this is Ph aurea then it may be borderline for winter damaged.

Mike McG near Brenham TX

[Mike McG]

... Do you have to constantly thin out the older culms to maintain a smaller bushy plant?

I forgot to add that that once a new bamboo shoot has leafed out it will never get any bigger (taller or thicker). Once you take a new division the original culm will never get any larger. The new shoots will usually be smaller, and then over the years, new shoots get larger, so other than the original culm(s) the older the culms the smaller they are. In general, the sunnier the location, the busier the plant will be. Also topping a new culm will tend to make it bushier.

Mike McG near Brenham TX

[joe lajeunesse]

the plants in the picture are golden beauty (not sure what the scientific name is). I took some divisions last month (my first ever) of aureosulcata and last week of japonica because they were available. I am watering them as needed and watering the leaves daily. I staked them all and mixed in some mycorrizhae organic root fertilizer to aid in the root growth. Anything else I can do to help establish my first grove? the aureosulcata is in a row about 70' and the japonica is about 10'. the aureosulcata is intended to be a dense screen, the japonica I was just lucky to get for free.

[joe lajeunesse]

also what can i expect next spring from these two varieties? Im not too concerned about the japonica, but I'd really like the aureosulcuta to fill out as quickly as possible. The culms are 15-20' tall and are spaced 3' apart with 2-3 strong culms per bunch.