clay soil in landscape

Discussion in 'Landscape Architecture and Design' started by Purkey Landscaping Co., Mar 5, 2009.

  1. Purkey Landscaping Co.

    Purkey Landscaping Co. LawnSite Member
    Posts: 1

    I have a project in the back of a residence that has alot of clay soil. In this spot we installed a Six foot dogwood tree and it keeps dying because every time we remove it to plant another, the hole is full of water. I think it is dying because of water in hole. What to do to get water out of hole so tree can survive. Need some help about clay soil.

    Perry Purkey
  2. Grassmechanic

    Grassmechanic LawnSite Silver Member
    Posts: 2,697

    You'll have to raise the rootball slightly above grade when you re-plant. Amend the clay and use it as backfill.
  3. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    1) Plant a more appropriate tree that can handle the soil conditions
    2) Find the source of the water problem and fix it.
  4. MarkintheGarden

    MarkintheGarden LawnSite Bronze Member
    Posts: 1,072

    It sounds like you created "hard pan" (compacted wet clay) at the bottom of the hole where you installed the dogwood. The result is no drainage and the roots get soaked, drowned and then rot.

    It can be nearly impossible to dig out the hard pan, but it can be done if the soil is dry.

    I would find another place to plant a tree if that is an option.
  5. AGLA

    AGLA LawnSite Bronze Member
    Posts: 1,742

    I agree with Kiril.

    My guess is that the source of the water is just surface runoff that is getting to the edge of your planting hole. Then it drains in through the looser material (your planting media or backfill) and fills the hole like a bucket. The area around the planting hole needs to be raised slightly (before putting the plant in the hole) with the existing soil in order to keep surface water from getting to the hole.

    Using unammended soil as a backfill is one school of thought that is increasing in popularity. That reduces how much easier it is for water to behave differently in your planting hole.
  6. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    Bingo. When you change the characteristics of the soil, you then change how it reacts to the environment. In my particular area this translates to soils drying faster than the "native" surrounding soils, which in turn causes people to dump more water on their landscape in an attempt to compensate. In heavy soils this results in the majority of the landscape getting over watered, which then leads to other problems.
  7. MarkintheGarden

    MarkintheGarden LawnSite Bronze Member
    Posts: 1,072

    When you removed the dead trees and found that the hole was filled with water, did you notice a rotten smell?

    If so, I respectfully suggest that you ignore what others have posted here and read what I posted about hard pan.

    Do not plant your dogwood in the same spot again, and do not plant a dogwood above the grade.

    In order to prevent this in the future, do not plant in wet soil conditions. If the soil is sticking to the shovel it is too wet to plant.
  8. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    No offense dude, but would you care to explain how one would go about creating a hard pan by digging a hole? Furthermore, I fail to see the relationship between a "rotten smell" and hard pans. A more appropriate term here would be confining layer. If he is digging in heavy clay, just the simple fact he has disturbed the soil leads to a change in hydraulic conductivity. Amend that soil and it is even a larger change.

    There are other possibilities as well, such as a high water table, or a natural low spot on the site which collects water.
  9. MarkintheGarden

    MarkintheGarden LawnSite Bronze Member
    Posts: 1,072

    When you work in wet clay a layer of hard pan can occur. If you stand in the hole while or after you dig it, hard pan is more likely. When we plant a tree, it dies and we re-plant a tree in the same spot, we have an increased possibility.

    I could type for an hour about hard pan, but you can read about it in many books, web pages, garden magazines, etc.

    a "confining layer" is a good term, and may be a better name for it, but the term hard pan has been in use since way before our time. There is a horticultural term I learned but it escapes me.

    When hard pan occurs at the bottom of a planting hole, water gets caught in the hole and does not drain. When you remove the plant it is good to see if the root was rotting or not by noticing the smell. This can help us determine the cause.

    Yes, this particular case may be due to some other cause than hard pan. I wish I could just come look at the situation, but I am in the clay capital of the USA.

    In my experience when I hear that someone has planted and re-planted in the same spot, I know the conditions are ripe for hardpan.

    The fact that the hole was full of water when he removed a dead tree is a pretty sure sign of some problem. If he planted a new tree into the water filed hole in the clay, then that is an almost certain recipe for hard pan beneath the new tree.
  10. MarkintheGarden

    MarkintheGarden LawnSite Bronze Member
    Posts: 1,072

    There are other possibilities as well, such as a high water table, or a natural low spot on the site which collects water.[/QUOTE]

    Sorry sometimes it takes more than one post for me to make my point, and that being:

    Yes, there are probably other factors, but if he did not have hard pan beneath the original tree, then it is almost certain it has occurred along the way during the replanting(s).

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