Asked on Dec 24, 2011

Should I amend red clay?

Amy GillDORLISTeresa


I finished my 3 foot retaining wall! Unfortunately the soil I used to backfill was typical red clay. I would like to plant hydrangeas, camellias, a fig tree and flowers. I plan to amend with composted horse manure. Any other suggestions? Bill in Williamson, GA
13 answers
  • 3po3
    on Dec 24, 2011

    The manure should help get you off to a good start, but I always suggest people start with a soil test through their local Cooperative Extension office. Here is the Georgia information: Tell them what you want to plant, and follow their directions for sampling the soil. They will tell you exactly what you need to add. The cost should be minimal, and well worth it. I did this for my vegetable patch this summer, and that alone at least doubled my yield, I think.

  • Douglas Hunt
    on Dec 24, 2011

    I agree completely with Steve about starting with a soil test. You will probably want to include some peat moss as well if you are growing camellias since they like soil slightly on the acidic side. I do caution you about the placement of a fig tree. They will get to be quite large (20 feet high and wide) and have a very robust root system that could damage your retaining wall.

  • Walter Reeves
    on Dec 24, 2011

    Two good posts so far...let me add a third: It's important to add the right amound of amendment to the soil and it all depends on how coarse the material is. If the manure is well-composted, I'd add an inch of it plus an inch of fine pine bark or composted wood fiber. If the manure is not fully composted, use two inches of it dug into the ground 8 inches deep.

  • 360 Sod (Donna Dixson)
    on Dec 24, 2011

    Bill did you put a drainage pipe and gravel behind the 3 foot retaining wall before back filling it?

  • Phil Bauman
    on Dec 25, 2011

    I agree, without the drainage, the wall will shift, with red clay it just a matter of time and rain. I recommend a bag of Black Kow, as a good start for the plants and amending the soil.

  • Bill P
    on Dec 25, 2011


  • Bill P
    on Dec 25, 2011

    Do I need to add Black Kow if I am adding composted horse manure?

  • Douglas Hunt
    on Dec 26, 2011

    Bill, if you have a source of well-composted horse manure there's no need to buy Black Kow.

  • Diane B
    on Dec 26, 2011

    Be care of the horse manure compost. There was a chemical used (weed killer) by many hay growers several years ago that has destroyed many garden. The chemical did not break down for several years. i found it out after the fact. Test it first to see if clear. Took two years and lots of amending to revive the plot.

  • Patty M
    on Jan 9, 2012

    Instead of tilling amending the entire area, I would only do that to the holes for the plants. Make the holes larger than normal, mix sand, compost, "good" soil and some clay together. Those roots need to be introduced to clay, otherwise, when they stretch and grow outside the hole and hit clay they can "stunt" if that makes sense. Also, if the whole is deeper than usual, the water can go away from the roots- Sand in the bottom (mixed with clay) is great. Clay hate sand! Lime is good too/ Google amounts or talk to a pro.

  • Teresa
    on Mar 26, 2015

    All the info sounds excellent! My only comment is...I live in Fl where sand is all I basically have to work with 😕& I'm from NC...can you say red CLAY?? Never knee I'd miss it but I do becsuse the taste of veggies grown in clay is awesome...all the minerals present!! The veggies I've grown down here have minimal if any delicious flvers!! Oh how I miss my red clay!!! I'll take any clay anybody has to offer!!!

    on Jul 25, 2015

    I agree with Patty M. I live on a bluff with red clay and rock. Every year new rocks heave up and have to be removed. I amend the area where I am planting and add lots of compost and leaves. This gives the roots a chance to grow into the clay and get used to it. Also, a lot of their roots will still be in the amended soil. I also put enough amended soil in the bottom so the plant is actually and inch or 2 above the original soil and add amended soil around it. Then if we have a hard, long rain, the plant won't get water logged. Someone had suggested that we remove the top foot of clay and bring in good soil. I am not rich so I did not do that.

  • Amy Gill
    on Apr 10, 2016

    In Virginia we have the wonderful clay too! I plan out what I will Plant and where, then I dig the appropriate size holes, I remove the clay, putting it into a bucket, then I make sure the hole is manageable with what is left(crumble or loosen the clay hole). In the hole I mix a equal amount of Peat moss and good Quality planting soil. Mix it up, then add the plant. I fill the hole with the planting soil, cover up around it with the remaining mulch, press it down around the plant to make sure you have compacted and air pockets. Then Water well. After watering, I return later and make sure the plant and soil around it is pressed down. So far, this has worked for many years of planting.

Your comment...