Black bamboo roots

Discussion in 'Poaceae' started by jackie, Oct 10, 2005.

  1. jackie

    jackie Member

    Messages:
    8
    Likes Received:
    0
    Location:
    Baltimore, Maryland, USA
    I am about to plant black bamboo in a small garden/patio area, which sits on top of a condominium garage. I don't know how far down it is but there is a fairly large (30 foot) fruit tree planted there now. My landscape person tells me that based on his reading and the lectures that he has attended, the roots grow no further than 6 inches down, and he will be building a concrete barrier of 12 inches around the roots (with no bottom). Is that information correct? Will a barrier of that depth be sufficient?

    Unfortunately, the plan is to start a week from today. Should I switch plans immediately???? Thanks for any advice you can give.

    Jackie
     
  2. Weekend Gardener

    Weekend Gardener Active Member 10 Years

    Messages:
    865
    Likes Received:
    1
    Location:
    Coquitlam, BC
    I am not sure I can visualise what you have in mind exactly. If your garden/patio sits on top of a condo garage, I would assume that the bottom of the growing media is limited by the roofing material of the garage. Is this roofing material concrete? Does it have any waterproofing material over it? Those are very pertinent questions to answer at this important juncture - before you take the plunge and plant that bamboo.

    As to the "depth of barrier needed", are you alluding to preventing the spread of the bamboo's spread or are you wondering if there sufficient media/soil for the bamboo to grow well. The answer to these questions can be different.

    Bamboos spread by rhizomes. These are designed for horizontal spread - i.e., sideways. And spread it can - rhizomes have been known to venture as far as 20 feet in one season. The concerns about running bamboo (and black bamboo is one of them) is just that - it's potential for unwanted spread. If the concrete barrier you mentioned is built sitting on directly on the roof of the garage itself, it would be fairly effective towards preventing spread. In this case, the height of the barrier does not matter, as there isn't anyway that bamboo can grow downwards (assuming that the garage is indeed concrete). But the barrier has to be secured. Otherwise, the forces generated by the advancing rhizome will eventually push the barrier apart. In the usual situation where the bamboo is grown in the ground, the depth of the root barrier needed depends on the species of the bamboo, but more importantly, it also depends on the type of soil. A friable sandy soil will require a much deeper root barrier than a topsoil which sits on hardpan clay just a foot down. So that with some soils as little as 12 inches may be sufficient, but in other types of soils, as much as 3 feet depth of barrier is needed. Also remember that root barriers do not stop the growth of the rhizomes - they just deflect their direction of growth.


    If the question is whether 12 inches is enough depth of soil, the answer is yes. In general, the bamboo roots and rhizomes will keep itself confined to the layer of topsoil with the most nutrients and will not venture deeper unless overcrowding occurs. Container grown bamboos are in general planted in containers no deeper than 12 to 18 inches and thrive well - I have a black bamboo (Phyllostachys nigra) thriving in just such a container. However, you will also need to consider winter survival. Although black bamboo is a temperate bamboo and is rated hardy to 0 degrees Fahrenheit, it may be more vulnerable if the roots are subjected to repeated freeze-thaw cycles. This is more of a risk if the volume of the growing media is smaller - e.g., less deep. You will need to figure out, based on your local climate, and on whether the roof of the garage gets sufficient warmth from the garage below to reduce the risk of excessive freezing, or repeated freeze-thaw cycles. And if so, what you might need to do to reduce this risk - e.g., increase the depth of the soil (in my opinion 12 inches should be more than sufficient for a bamboo to thrive, but the total square footage is also important), or mulch in the winter.

    Last, but not least, you need to answer that question about the possibility that the roof of the garage may have a roofing membrane installed for waterproofing. Bamboo rhizomes, more than any tree roots, pose the greatest risk of disrupting that membrane. This may turn out to be costly. So, do find out.
     
  3. jackie

    jackie Member

    Messages:
    8
    Likes Received:
    0
    Location:
    Baltimore, Maryland, USA
    Thanks very much for your most helpful answer. Apologies for not being clearer. Let me clarify. I'm on the ground floor and the patio, which is about 70 feet by 20, extends partly over the underground garage. I don't know how much topsoil there is between the surface and the top of the garage but there is enough for a fairly big weeping cherry or some other fruit tree to have been growing there for some 20 years. The roof of the garage is concrete - the whole building is brick and concrete.

    My main concern is that the roots of the bamboo will grow downward. I have read and been told that the roots run laterally, which you confirm, but your statement that "root barriers do not stop the growth of the rhizomes - they just deflect their direction of growth." makes me wonder if they will run downward when they encounter the barriers. The barriers will not go all the way to the roof of the garage.

    I don't know if there is waterproofing membrane on the roof and will check - would you know if there would have been in the 1970's? Also, I don't know what kind of soil will be involved but will definitely find out!
     
  4. Carol Ja

    Carol Ja Active Member 10 Years

    Messages:
    672
    Likes Received:
    1
    Location:
    Salt Spring Island
    I would imagine that it won't go downwards, bamboo can outwit people to a certain extent, but it can't go against its own nature. It really only normally grows lateraly. Weekend is (I think trying to tell you that if you put a barrier down to stop it growing straight off to left field, it will turn right. (not down).
    Might I suggest one of the many clumping varieties? They are a lot less scary for people. Also they handle containment better.
    Carol Ja
     
  5. jackie

    jackie Member

    Messages:
    8
    Likes Received:
    0
    Location:
    Baltimore, Maryland, USA
    Thanks for your answer. That clears the air, as far as I'm concerned. I'll dig around it in a year or so to see how it is doing. I shall also report back. This site has been wonderfully helpful.

    By the way, I wanted the non-clumping variety because of its shape. I was looking for a kind of umbrella/canopy effect.

    Jackie
     
  6. Carol Ja

    Carol Ja Active Member 10 Years

    Messages:
    672
    Likes Received:
    1
    Location:
    Salt Spring Island
    I thought you might like to see this picture of a clumping Thamnocalamus tessellatus.
    It's a pretty nice specimen.
    Carol Ja
     
  7. jackie

    jackie Member

    Messages:
    8
    Likes Received:
    0
    Location:
    Baltimore, Maryland, USA
    It may be just that I don't know how to access it, but I can find no attached picture.
    Jackie
     
  8. raceyladie

    raceyladie Member

    Messages:
    4
    Likes Received:
    0
    Location:
    St. Catharines Ontario Canada
    Jackie
    I have Japanese Bamboo in my backyard that I am trying to get rid of. I do not know who planted it but it is impossible to get rid of . If you wait 2 years your whole patio area will be bamboo. Is this what you want?
    raceyladie
     
  9. jackie

    jackie Member

    Messages:
    8
    Likes Received:
    0
    Location:
    Baltimore, Maryland, USA
    Thanks for your concern. I too worried a lot about invasive bamboo. That's why we're putting concrete barriers around them. I am assured that should work!

    jackie
     
  10. Weekend Gardener

    Weekend Gardener Active Member 10 Years

    Messages:
    865
    Likes Received:
    1
    Location:
    Coquitlam, BC
    The lesson to learn about growing running bamboo is to "close the gate before the horses bolt". Jackie is doing the right thing in thinking ahead, and installing adequate root barriers. It's when bamboos are planted without root barriers or annual rhizome pruning that it's invasiveness raises it's ugly head.
     
  11. monet

    monet Member

    Messages:
    2
    Likes Received:
    0
    Location:
    Katy, TX
    Just signed up on this site and I'm already finding it helpful. In regards to black bamboo. My husband and I planted this about 2 1/2 years ago in the corner of our yard. I have been asking him to confine it some how and he has neglected doing so. Well this Spring, it is starting to take off! My question is how can we confine this growth to only a certain area? I'm guessing that we can perhaps insert sheets of plexiglass into the soil to prevent the roots from wandering. Again only assuming. If this is sufficient, how deep (8" plexiglass sheet sufficient?) and how shallow should we insert the plexiglass? I do not want these sheets to stick out of the ground because my beloved Bailee (dog) loves to hawl booty into this area chasing away the birds and I do not want her to trip up on it and cut her leg as she has already done on our lighting. Thanks for anyone's assistance!
     
  12. jimmyq

    jimmyq Well-Known Member 10 Years

    Messages:
    2,345
    Likes Received:
    0
    Location:
    Metro Vancouver, BC, Canada.
    Re: Black Bamboo - Confining

    www.deeproot.com
    there is a product they have as a water barrier that is useful at confining bamboo.
     
  13. jackie

    jackie Member

    Messages:
    8
    Likes Received:
    0
    Location:
    Baltimore, Maryland, USA
    I also found this site immensely helpful when I was planning to plant my black bamboo. Being extra cautious, I planted them in bottomless containers 24" deep. That was in 2005. So far the roots don't seem to have spread. I was worried they would grow downward but one of the helpful responders to my query said they wouldn't do that, it would be against their nature. I plan to dig up one of the plants later this season to see what it's doing, and perhaps to cut it back.

    Good luck!

    Jackie
     
  14. monet

    monet Member

    Messages:
    2
    Likes Received:
    0
    Location:
    Katy, TX
    Thanks Jackie, I guess I can assume 24" deep should be sufficient? It seems as though the runners (?) are keeping just below the top of the bed and not running too deep.

    Thanks again!
     
  15. jackie

    jackie Member

    Messages:
    8
    Likes Received:
    0
    Location:
    Baltimore, Maryland, USA
    A few of the runners ran over the top of the container but were easily detected and cut off. I've yet to dig up one of the plants to verify that no roots are growing downward. Will report.
     
  16. go native

    go native Member

    Messages:
    1
    Likes Received:
    0
    Location:
    Victoria
    Ooh! my first post here. Just felt I had to weigh in here cuz I have a little experience containing bamboo. the concrete barrier mentioned at the top of this thread probably worked fine (posted Oct. 05) but it seems like a lot of work and if it cracks then the bamboo can shoot right through it. Plexiglass is not a good idea because the bamboo will easily force its way through the unconnected ends of the sheets. I think what you want is a continuous run of 12" - 18" wide plastic or metal sheeting sufficient in length to encompase the plant at the largest desired spread.

    Five years ago my brother's front lawn was thoroughly infiltrated with runners from his Golden bamboo patch. He hired a couple of guys to dig up each runner back to the main patch, they did a great job. I went in with a 12" wide length of plastic garden edging long enough to surround the plant and overlap the ends by 4 feet. It's a bit of work digging the trench but it worked great, not a single runner has escaped.

    I just planted an 18 foot tall clump of black bamboo in my yard inside a meandering designed barrier of 12" aluminum flashing material. It comes in 25' and 50' rolls of various widths. Aluminum may corode faster than plastic so we'll see what happens. If you place the barrier on an angle, slightly, so the bottom edge is closer to the plant then you are guarranteed the runner will be deflected upward when it strikes it. A small, angled, fold across the width of the metal, with the larger part of the fold at the bottom will make your barrier smaller at the bottom, giving you the angle I referred to. Keep the top edge 1/4" below the soil surface if you want it hidden (my preference) and you'll easily see any runners trying to escape. Hope that was clear but not too wordy.
     
  17. edleigh7

    edleigh7 Well-Known Member

    Messages:
    1,769
    Likes Received:
    1
    Location:
    Brisbane Queensland Australia
    G'day everyone...are we talking about Phyllostachys nigra, Black bamboo. If so it is invasive (as said earlier) if you do not want invasive bamboo in your garden (as I or my neighbours wouldn't), why don't you try a clumping bamboo like Bambusa lako, Timor black. If the clump gets too much simply snap the new shoot off with your foot when it gets to 6 inches high. If you are in a cold climate there is other black bamboos available. I know this is an Aussie site but it might give you some ideas, and you could source your plants elswhere. Try this www.bamboowholesale.com.au/html/black_bamboo.html Good luck

    Ed
     
  18. jackie

    jackie Member

    Messages:
    8
    Likes Received:
    0
    Location:
    Baltimore, Maryland, USA
    An update on my black bamboo experiment of a year or so ago, in which I planted the bamboo in thick plastic pipes of 24" diameter and 24" deep (essentially a very large pot without a bottom). This spring I found a few runners had spread on top of the soil but they were easily located and cut off. What I had most feared was that the roots would grow downward below the 24" pipe and run laterally from there. One of the persons replying to my initial post assured me back then that they wouldn't but being a total beginner, I worried anyway. So this spring I dug up one of the plants and found that the roots had gone down about 15" but no further. In other words, my experiment worked fine.
     
  19. edleigh7

    edleigh7 Well-Known Member

    Messages:
    1,769
    Likes Received:
    1
    Location:
    Brisbane Queensland Australia
    Sorry...I didn't realise this thread was so old...good to here your experiment worked anyway.

    Ed
     

Share This Page