Trees Are Good - The International Society of Arboriculture's consumer website has links to many terrific publications on tree care, planting, pruning and more.
City of Austin Grow Green - The Native and Adapted Plant Guide for the Austin area boasts a wealth of information on all things green from turf to trees, including size, sun and watering requirements. The insect and disease section offers solutions for many locally common problems. Pesticides are rated from least to most toxic.
Central Texas Horticulture - Travis County Horticulturist Skip Richter packed an enormous amount of information on landscaping, lawns, gardens and all things green into a user-friendly site. There’s also information about insects, plant diseases and unwelcome weeds. Check it out!
Watering Urban Trees
As temperatures rise, trees need water to stay healthy. Many mature native trees are able to survive periods of drought, but most will benefit from some supplemental water after 4 to 5 weeks without rain. The quantity of water needed to keep your grass alive may not be enough for your trees.
You can use a screwdriver to determine if the trees need more water. If you can push the screwdriver at least 6-8 inches into the ground, then the soil is sufficiently moist to sustain your trees. The screwdriver won't penetrate the ground when the soil is dry. Check the soil moisture frequently to determine when it's time to water.
It's normal for many trees to drop some leaves during extreme heat. If leaves start raining down from your oak, though, it could be oak wilt. Call an Oak Wilt Qualified Arborist to schedule an inspection.