Planting, watering methods key to new trees
I purchased a flowering pear tree from you, followed all instructions on your handout, and took pictures with each step. I am really worried. I have included three pics I just took of the leaves. When it was delivered, it had several leaves with some black edges, but otherwise it looked good. What’s wrong?
I’m not too worried about the tree; it’s not on the verge of dying on you. It is telling you that it’s unhappy about something. This is usually because of one of two things — improper planting or watering issues. Planting issues involve how deeply the tree was planted. A tree growing in a container comes with a dark-colored cylinder of soil mix. It’s important that the top of that cylinder is exposed to the air.
In fact, I like to plant the tree an inch or 2 higher so the base of the tree is elevated a bit, then gently slope the soil down away from the sides of the rootball.
The roots of plants breathe — that is, they respire. It requires work for a root to absorb the water and nutrients the tree needs, and it gets that energy from respiration like we do.
While the tree was in the pot, it was used to oxygen percolating down through the surface of the rootball.
If that rootball is buried, there’s less oxygen available to the roots and they can’t work properly. In severe cases, it can lead to death of roots and the potential loss of the entire tree.
If your tree is too deep, it needs to be dug up, some additional soil packed at the bottom of the hole and replanted. Since the tree is very new, this shouldn’t hurt it.
The second possibility, watering, is the most common problem. It’s either getting more water than it needs or not enough. This is an easy problem to solve simply by doing a bit of poking around in the soil by the tree to check soil moisture.
First, make sure that the tree is deeply soaked when you do water. Sometimes when people worry about overwatering their trees, they react by skimping on the water when they do water. Overwatering isn’t about how much water you give a plant, it’s about how often you give water to it. The goal is to deeply and thoroughly soak the rootball and the surrounding soil. I want penetration down 12 to 18 inches after watering.
It’s a good idea to check this by waiting an hour or two after irrigating and verify that you have wet, muddy soil down to that depth.
Next, check the frequency of watering; make sure that the soil has a chance to dry out slightly before soaking it again. The tendency for most people is to overwater because of our hot, dry climate. They care so much for their new additions that they sometimes “kill them with kindness.” If the soil stays saturated for an extended period of time (especially in our heavy clay soils that don’t have a lot of pore space for oxygen to be available to the roots), the roots shut down and even begin to die because there’s too much water. The roots can’t function like they should (again, because they need to respire).
Checking this involves some digging into the soil as well. I like to dig down 3 or 4 inches in the soil and feel it. There should be some moisture there.
Mona, my front counter manager, said to let it get to the consistency of unbaked pie dough and I think that’s a pretty good analogy.
Do some digging around in the soil to see for yourself. You don’t have to be digging down forever. Doing this for a few weeks will give you a good idea of how your soil is working and when and when not to water.