I would get another soil test since you don't know where the sample came from. Contact your county extension service. It seems a little odd to have high calcium with low pH, and high phosphate in an area that hasn't been heavily fertilized.

If the soil test actually does represent the proposed garden area, pH and organic matter are fine. High phosphate should be a flag. Don't ever apply superphosphate or any high P fertilizer, because excessive P can make trace elements unavailable. Also, roses use 3x as much N as P, and twice as much K as P. Look for fertilizer with a 3-1-2 or 2-1-2 ratio of NPK. Mg and sulfur can be added as epsom salts, 1/4 cup per square yard applied at the surface.

Clay soil is fine for roses. Just don't work it or step on it when it is wet. If drainage is questionable, just bring in some more soil to raise the area 4-6" above the surround.

Don't prepare separate holes, but amend the whole area uniformly by digging in a few inches of manure or compost to a depth of 10" and removing most of the rocks. I wouldn't dig in a lot of nutrients because they can all be applied from the surface and the clay will hold them.

Actually it sounds like, unless the area has been compacted, you don't need to do much.

Mushroom compost is not recommended because it is usually highly alkaline. Roses prefer moderately acid soil.

Thank you Michael for your fast response and easy to understand at that. I think I will get another sample , and the thought occurred to me , that I'm sure he ordered the sample with the intent to fix his soil , so I probably can't rely much on this at all. Unless he never did the treatments to the whole yard .
Can I apply Epsom now or wait to spring ?
I'm not sure if I would call it compacted , but the lack of rain here and the rocks make for a heck of a time shoveling . I was using my pick a most of the way .

lilyfinch the high Phosporus is not unusal around here, in fact there here has been quite a bit of phosphate mining in the area over the years. Mine is high as well. I've added horse manure compost to my local clay soil and am very happy with the results, but do check with the UT Extention office. They are very reasonably priced.

If you decide you want manure compost let me know. We are in the middle of a very horsey area and there is lots available if you know where to look.

I wouldn't apply Epsom salts until the roses are planted. It will dissolve easily and enter the soil, where the clay will grab the Mg. Also I'd get a soil test first, in case the other folks have already adjusted. 1/4 cup/yd is a light dose that could be repeated the following year. Or the soil test may recommend adding a certain amount. It's important to remember that too much of any nutrient is bad. (No need to worry about the high calcium, though.) Thanks to subk3 for the helpful info about phosphate.

Hi subk3!
I am lucky enough to live right on the edge of someone's horse and cattle farm. If I can ever bump into the farmer again ( he dosnt live on the property ) I am going to ask about getting some .
Otherwise , I am in burns if that is familiar to you . Glad to hear you still have good results with our soil ! I guess I won't worry as much as I was ! Thanks !!

If the clay is too hot and baked and therefore hard to dig in, run the sprinkler for several hours and let the water soak in overnight--or for 24 hrs (or more) if it is still to wet. When it gets down to moist but not wet, try digging. Should be much easier.

But don't tromp around in it while it is wet, or you will definitely have compacted soil (if you didn't before).

Kate

Michael is so right about preparing the whole bed.

On the house pad where my primary rose garden in located, I have what amounts to glacier slurry/subsoil. The house pad was cut out of a slope created by glacier runoff eons ago.

Once the decorative rock the previous owners used for the back of the house was scraped off, I was left with soil that was mostly rock with clay and silt between the tightly compacted rock.

My huge novice mistake was to dig rose holes instead of preparing the whole bed. I created a gardening nightmare.

I cannot buy soil or mulch up here, but I could buy bags of compost.

I mixed a lot of compost with the native soil and screened out a lot of the rock from the native soil that I mixed with the compost when I planted my first roses. As the compost decomposed, the roses sank! How much they sank depended on how much organic material I mixed in with the native soil.

I have since found that all of those rocks do not decompose and allow for good drainage in clay soil. I don't screen them out any more. In fact, I add rocks to my back fill instead of organic material and mound the soil in the planting hole UP so that when the rose sinks due to the OM around the root mass decomposing, it settles at the level that I want for the rose.

Over the years, I've applied all of my organic materials on top of the soil. I have perfect drainage due to the rocks and the clay between the rocks held moisture quite well. I found that it is much easier to correct the nutrients values than to try to correct drainage.

Putting the OM on top has actually improved my soil. Until the extreme drought, I had plenty of earth worms and the soil gradually became more friable. It is not fertile, yet.

None of my roses died and except those that are not suited to my climate, all of them have done quite well.

I do think that had I prepared whole beds properly with as much OM as possible and allowed it to set until the OM decomposed, I would have had an easier time of it in the long run.

Kate ... I have so much rock in my soil, I can walk on it when it is fully saturated. Common sense would tell one that this is not the soil environment to grow healthy roses. The good news is that the roses don't know that. They just want to grow.

Smiles,
Lyn