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flo617

messing up the soil

flo617
9 years ago

Hello,

I never really gardened before. I recently had to prep the soil and I wonder if did make a big skrew up work.

The soil I'm working with is thick clay in general. My garden has a fairly deep sump (4ft?) at the very end corner of the garden (sort of the lowest spot, only sort of though).

So I thought I would improve drainage by digging one foot deep and laying a couple inches of rocks (I used white marble chips from home depot) slightly inclined towards the sump (I have yet to drill a few weeping hole through the concrete sump).

I then filled up with amended soil (using a "clod breaker" mix from a local landscaping source) and raised about 8" above the existing level (using a straw wattle as the bed edging).

In this fairly shady place I planted native Californian plants (pink flowering currants, Western Virgin's Bower, wood rose, yerba buena mint, western bleeding heart, wild ginger and redwood sorrel). I am planning to mulch with shredded redwood bark (gorilla hair)

Now I am worried that the stones will turn my soil alkaline and that I might have made life hell for the roots of the shrubs.

I just planted last week. Should I excavate and remove those rocks?

Those are really pretty plants and I don't want to do a massacre.

Thanks

Comments (5)

  • jean001a
    9 years ago

    How extensive is the rock layer you added. In a sort of "channel" or "stream" pattern?
    Or underlying an entire bed?

  • flo617
    Original Author
    9 years ago

    It's in a stream pattern with the center going maybe 2" deep (not more than 3" ) an tapering down around the center. The total width is about half the width of the bed

  • Pyewacket
    9 years ago

    It is likely that your plants will just grow roots under or even through it - I'm assuming its only a few inches thick, and not a trench a foot deep filled with rocks?

    I don't think you've ruined anything, but I don't think you've necessarily improved anything either. At least not with the rock - the raised beds are a good idea.

    I'm guessing what you were aiming at was something like a French drain, which can be very useful for helping to drain a damp patch of ground. They used to put them around houses but hardly ever do now. It's labor intensive and the do require maintenance over time - but boy they work well when they're properly installed!

    If its not too much work, pulling that rock out so you can reuse it to build an actual French drain would at least put it to good use.

    There are other ways to provide drainage that might work better, be easier to implement, and be cheaper to install. I don't know that much about trying to drain wet spots.

    Just be careful - it is actually illegal to drain "wetlands" throughout most of the country, and you'd be surprised what might get labelled a "wetland".

    Don't get me wrong - I'm all for preservation of actual wetlands. But sometimes they go overboard designating some little patch of swampy ground as an actual "wetland reserve".

    Here is a link that might be useful: About French drains

  • toxcrusadr
    9 years ago

    Unless you put a landscape fabric over the rocks, the soil is going to fill in the spaces in between fairly soon, which will eliminate most of the drainage capability. Just FYI.

    White marble chips will not siginificantly change the pH over the long haul. Crushed or powdered lime will have a greater effect because of the higher surface area. I wouldn't worry too much about the pH.

  • flo617
    Original Author
    9 years ago

    Thanks for the replies,

    Yes I was trying to achieve kind of a french drain. Come to think of it that as probably fairly useless as the soil naturally drains out to the neighbors (we are on a hill and the neighbor's yard on this side is lower than us. I realize that now that things are a little more settled.

    The way I see it, it could affect the pink currant and the western virgin;s bower in terms of depth (maybe the wood rose too) but they have a lot of room to grow before that happens. I hope the mulch will compensate for any leeching of alkaline material. If the rocks won't be harmful to the soil I'd rather leave it in there rather than creating more mess in the garden.

    I wish I had found the warnings about growing CA native plants before I did all that work. I guess most of the time when people discuss "gardening" it means vegetables. I'll be more careful next time.

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