Ask Mr. Smarty Plants

When we first read your question we figured you HAD to be from around Austin, and we were going to warn you that digging much deeper in that rock might cause you to hit the Edwards Aquifer. Turns out you're in far North Central Texas, almost to the Red River, which we always thought of as more nearly sandy East Texas soil. So, Mr. Smarty Plants can be wrong, frequently is. Are there native Diospyros texana (Texas persimmon) already living in your area, wild? There easily could be, as its habitat is in North, Central, East and West Texas, in rocky soil, open woodlands. Another question: Can your plant out of the pot fit into the hole you already have without the roots resting on that rock? It sounds like it probably will. You don't want to present newly planted baby roots with a rock wall their first day out of the pot.  You and your jackhammer have already taken care of that.

So, here's the plan. You're going in the right direction adding some dirt and raising the bed, not just because of the rock, but because the persimmon needs very good drainage. And instead of just adding dirt, add some good compost and mix it in a fairly wide area around your hole. Before you put that plant into the hole, do some root pruning. Two years in a pot, and those roots are probably circling around and around, hunting fresh dirt, which you are about to provide them. Unfortunately, once roots get going in that circle, or root-bound, they are not naturally inclined to come out of it. So, go around with heavy clippers and cut some of those roots through. We know this sounds brutal, but they will survive, and those cut root ends will start putting out rootlets to find the nutrition and water the plant needs to survive. The reason we are recommending that you amend the soil fairly far around the tree root is that when those roots first hit that rock beneath them, they are going to start to spread. Most tree roots are in the upper 6 to 12 inches of the soil anyway, where they can access moisture, nutrients and oxygen more easily. Because you probably have alkaline soil, as most of Texas except East Texas does, the compost will help those roots access the trace elements in the soil that they need, as well as contribute to the good drainage this plant requires. Last, mulch your newly-planted tree with a good quality shredded hardwood mulch, which will help hold in moisture and protect the roots from heat and cold. As it decomposes (and you will have to replenish it from time to time) it will add further to the organic compost of the dirt and continue to improve the texture. Two or three times a week, stick a hose way down in that newly planted soil and let it dribble very slowly until water appears on the surface. Do this until you're comfortable that the tree can make it on its own. And get that tree planted soon-don't ever plant anything in the Texas heat, as that can cause transplant shock, and you could lose the whole tree, and all the effort and jackhammer expense you have already put into it.  

Diospyros texana

Diospyros texana

Diospyros texana

Diospyros texana