Planting under cedar trees

Discussion in 'Garden Design and Plant Suggestions' started by Gwen, Aug 6, 2007.

  1. Gwen

    Gwen Member

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    Edmonds, WA
    We've got two giant Western red cedar trees in our backyard with nothing growing under them. I'd like to add mulch/compost and plant some native plants there. Are there any cautions for disturbing the soil under these trees? I plan to add 3-4 inches of compost and the supplier recommends 5-10 pounds of dolomite lime per cubic yard of compost. Is this OK for these cedars? I'm also interested in native plants that provide food/cover for wildlife. Any recommendations? I've got two little boys and their sandbox is under these same trees, so plants with berries that are toxic to people are not an option. Thanks!!!
     
  2. Annell

    Annell Active Member

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    hi! Were told by an arborist once to not pile up to much soil against the back of our cedars, as the moisture would rot the bark. But a few inches would be okay. Under our cedar tress we have the following plants. They all do very well, so long as we rake up the cedar 'leaves' that fall each year. We do this once in the fall and once or twice in the spring.

    I also have a small boy who likes to dig, so we made sure the berry's were eatable.

    We're growing:
    Huckleberry,
    Salmon berry,
    Hostas
    Sweet Woodruff
    Bleeding heart
    Solomon Seal- small berries- not eatable- but not very attractive
    Sword Fern and Bracken Fern
    Periwinkle

    Holly, Lily of the valley- also seem to be doing okay under one of our cedars, but they are, of course, poisonous if eaten.

    We add some soil and compost each year to counter the acid. I think that it's the leaf drop that's the acid issue and it that's kept cleaned up then everything grows well.

    Next year I plan to plant some Nootka Roses - native roses, to grow along the fence under our cedar.

    Good luck!
    Anne
     
  3. unther

    unther Active Member

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    Newberg, Oregon, USA
    I'd like to echo the advise against excessive mulch. The great thing about large trees is that they're self-mulching. The gardener need not do a thing (except do a bit of weed patrol)--the tree has applied your mulch for you and in the correct amount. Leaf-drop shouldn't be a concern with regard to pH, particularly since you're growing a native plant within its native range. If the plants you place beneath it are the same species found growing with it in the wild, you're good to go--it'll all take care of itself (except for a bit of extra irrigation while they're establishing themselves).
    One plant I'd add to the list is Vancouveria, the inside-out-flower. It can take a considerable amount of dry shade.
    I'd avoid Vinca and Ilex, as they can be rather weedy. If you like the look of Convalaria, you might consider substituting the native Maianthemum dilatatum.
     
  4. eric_r

    eric_r Active Member 10 Years

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    We have three very large cedar trees in our front yard. They are not native western red cedars but some horticultural variety that were likely planted here about 75 years ago and grew out of control.

    In the shadiest, driest spot right under one of them we have been able to grow toad lily (tricrytis), hosta, epimedium, and Solomon's seal (polygonatum). In slightly more benign spots a little farther from the tree trunks we have been able to grow almost anything -- even a Kiftsgate rose that is gradually trying to climb one of the trees.

    One of my concerns has been the annual autumn leaf drop. I understand from Unther's post that the only possible negative effect of the leaf drop on surrounding plants is the acidity of the soil. I had been wondering whether to hand-rake the fallen leaves in case there was any other deleterious effect, but it sounds as if as long as the plants are acid-loving (e.g. rhododendrons, heathers, enkianthus, etc.) there should be no negative effect of the acidity, and the mulching effect would be a positive one. Is this correct?
     
  5. Ron B

    Ron B Paragon of Plants 10 Years

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    Put down some fine bark or similar mulch and see what birds bring. Watering mulch in summer should result in a thicket of bird-sown trees and shrubs, select ones wanted and jerk out the rest. Skip the dolomite. Put a removable cover on the sandbox if you don't have one already, otherwise unconfined cats are pretty much bound to soil it.
     
    Last edited: Oct 20, 2007
  6. KarinL

    KarinL Well-Known Member 10 Years

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    I have been gardening under a neighbouring Chamaecyparis lawsoniana cultivar for 15 years and have finally given up and asked the neighbour to remove the tree - the root encroachment and tsunami of debris and the dryness due to the thick canopy render it a task that is highly labour intensive and not very rewarding. (There are other issues besides gardening, as the tree also envelops and threatens our house). The acidity is also of course an issue. What I have found is that I plant large clumps of plants that have grown too large elsewhere in the yard, and they steadily shrink from the time I plant them under the tree until I give up and put them in pots or elsewhere in the yard. Very few plants thrive there without constant watering, and most would suffocate if I did not constantly remove debris. The conditions are also ideal for weevil habitat, so I have an endemic population of them that is hard to combat. Also, it is a dry, dusty, spider-infested place under the tree that is very unpleasant to be in during summer.

    If you are lucky enough to own the trees under which you want to garden, you should consider removing the trees and planting new ones as part of your design. It is not politically correct to say so these days, but there is a point at which trees, especially conifers, become too large for urban environments, especially if they limit the neighbours' options for their properties as much as they limit your own.
     
  7. unther

    unther Active Member

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    >We have three very large cedar trees in our front yard. They are not native western red cedars but some horticultural variety that were likely planted here about 75 years ago and grew out of control.

    I wouldn't expect that to be any sort of issue. You might, if out of nothing more than curiosity, attempt to identify them. There are several differnt trees that are called cedars. Some are very closely related, such as western red cedar (Thuja plicata) and incence cedar (Calocedrus decurrens). Others are not related to our natives, such as deodar cedar (Cedrus deodara), which really bears no resemblance to the former two. How they all came to be called cedars is beyond me.

    >In the shadiest, driest spot right under one of them we have been able to grow toad lily (tricrytis), hosta, epimedium, and Solomon's seal (polygonatum). In slightly more benign spots a little farther from the tree trunks we have been able to grow almost anything -- even a Kiftsgate rose that is gradually trying to climb one of the trees.

    It sounds like you should have little trouble growing any of your locally native woodlanders under this tree.

    >One of my concerns has been the annual autumn leaf drop. I understand from Unther's post that the only possible negative effect of the leaf drop on surrounding plants is the acidity of the soil. I had been wondering whether to hand-rake the fallen leaves in case there was any other deleterious effect, but it sounds as if as long as the plants are acid-loving (e.g. rhododendrons, heathers, enkianthus, etc.) there should be no negative effect of the acidity, and the mulching effect would be a positive one. Is this correct?

    Sort of. Soil acidity is largely related to underlying soil type and annual rainfall and only to a lesser degree to the sort of leaf litter encountered. The presence of conifer duff may lower the pH, but it won't be enough to be a problem to most native plants. The only leaf fall that might possibly be a problem might be that coming from large-leafed trees such as bigleaf maple (Acer macrophyllum) and only then because the large leaves might smother herbaceous plants--unless they're species that naturally grow under BLM's.
     
  8. unther

    unther Active Member

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    >If you are lucky enough to own the trees under which you want to garden, you should consider removing the trees and planting new ones as part of your design. It is not politically correct to say so these days, but there is a point at which trees, especially conifers, become too large for urban environments, especially if they limit the neighbours' options for their properties as much as they limit your own.

    Also consider safety. If a tree is threatening life, limb, or property, I don't think anyone would rationally object to at least a judicious pruning of offending limbs.
     
  9. asten66

    asten66 Member

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    well i am facing the same problem,.,,, the grass is not appearing under the big trees please help me in this matter
     
    Last edited by a moderator: Jan 10, 2008
  10. M. D. Vaden

    M. D. Vaden Active Member 10 Years

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    Generally, if big trees have a lot of established roots, I prefer to plant small sizes like 1 and 2 gallon rootballs, because less damage is done to the tree roots.

    Just depends on how many big roots are there to damage, or not.
     
  11. unther

    unther Active Member

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    >well i am facing the same problem,.,,, the grass is not appearing under the big trees please help me in this matter

    While working for a landscaping company, I saw quite a few situations in which someone was trying to force grass to grow in a place where it really didn't want to grow just because they wanted it to grow there. My advise is: STOP FIGHTING IT! If you want to grow something under shady trees, try planting something that naturally grows under shady trees. It seems like a no-brainer to me.
     

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