Just planted a Mount Royal plum. The soil was very hard with clay and lots of pebbles. So I dig up a hole 2 1/2 feet diameter and 2 1/2 feet deep and filled with triple mix and planted the tree on the top . I didn't re use the soil at all. But now I realized that complete new soil is not a good idea? Is that very bad?
The roots of your plum will not want to leave the good soil part of the ground; so you will effectively have a potted tree. This may be good or bad, depending on the desired ultimate size of the tree.
Thanks for your comment. I replanted it today with removing the triple mix and add more old soil. The bottom of the hole was very bad. The water at the bottom with triple mix made the bottom part of the hole very soggy. The triple mix was very bad idea. Now my worry is will the water will stay at the bottom and ruin the plant? The hard clay with pebbles is like concrete. What to do?
Try a soil drainage (percolation) test in the ground next to the tree planting excavation (but not too close). The drainage rate should be at least 1 inch per hour. If it's less, you will need to do something to improve the drainage around the site, which is not an easy task. A berm or raised bed might be the simplest way to fix the problem.
We have possibly worse clay conditions in Grande Prairie, AB where I planted a Mount Royal @4 years ago. As we don't get masses of rain here we haven't be concerned about the drainage issue. After getting a few plums the first year and masses of new growth, we are finally set to get a bumper crop. We planted in good quality top soil.
We dug a similar sized hole, having excavated what is called gumbo clay, around here. It's the worst sort of clay I've ever come across.
I have had very good results by using Gypsum ground to powder size. About 1/2Kg (1lb.) scattered around the base of the tree/plant will do. You can't get enough of this stuff in the soil. Water in deeply. Gypsum will open the hardest clay. Around here there is a product named "Sod Buster" in the farm supply stores, but I prefer the pure,white Gypsum.
UPDATE I just came from the farm supply store and find that the name of the product is "Soil Buster not Sod Buster made by Best Company in the U.S. When I had my farm I used to buy Gypsum by the truckload from local dealers. The Domtar company in Canada makes this product. The results can be spectacular. It will "open up" the hardest clay soil ever seen. KK
