In a place as hot as Dallas, Texas, shade trees are as precious as air conditioning. But even so, it is easy to take our leafy guardians for granted until they get sick. When they do get sick, some diseases like the hypoxylon canker spread with the ruthlessness of a medieval plague.
Healthy Trees Don’t Get Sick
But the good news is that trees are a lot like humans–they get sick when they are stressed. When humans eat well, sleep well, and hydrate, their bodies have enough excess energy to bolster their immune systems. In the same way, when plants have surplus energy, they produce complex sugars that are literally indigestible to insect pests. They also develop strong cell membranes that resist many bacterial and fungal pathogens (Advancing Eco Ag). If we can pay a little bit of attention to our trees while they are healthy, they are a lot less likely to get sick.
Support Your Soil Life
Tree health begins where human health begins–in the gut. Fertilizing is very important. But just like microorganisms in the human gut, microbes in the soil drastically improve the ability of trees to uptake and use nutrients. At Chambersville Tree Farm, we use compost tea, compost extract, molasses, fish products, and “bug grub” to ensure a healthy soil life in our potting mix. We also use a container system that facilitates the development of a strong, branched root system that will quickly accommodate to its new soil once transplanted.
Once your tree is in the ground, it is wise to continue to support the soil life around your tree. You can buy root inoculants to add when you plant your tree, and a good dose of compost tea every few weeks is a good idea. But unless your microbes have something to eat, they’re not going to stick around too long. Organic matter is their favorite food, so try mulching with organic straw, shredded leaf litter, or bark mulch–the more decomposed, the better. Earthworms also like organic matter, and they will aerate the soil as they tunnel through it. The good news is that all this hungry soil life poops a lot, and that poop is free slow-release fertilizer.
Keep your Soil Moist
The biggest advantage of mulch, of course, is that it retains water in the soil. The most stressful moment in a young tree’s life is transplanting. No matter how drought tolerant a mature tree may be, young trees with their shallow roots need ample water to establish. Drought can also be the reason for the demise of mature trees. According to the Texas A&M Forest Service, the hypoxylon canker only targets oaks and hardwood trees undergoing significant stress; in Texas, that stress often comes in the form of drought.
Choose the Right Tree
So you’ve watered, mulched, fed, and coddled your new pear tree, but its tips are still withering away with fire blight. Well, the truth is, some plants just don’t grow very well in Texas. The first step in tree health is choosing trees appropriate to your area. When you can, choose natives like desert willows, chinquapin oaks, or junipers that are adapted to our climate. And if you are desperate for a fruit tree, try a plum instead of a pear.