Recently I inspected the trees and landscape plants at a residential property with nearly 300 perennials, from lantana and Mexican heather all the way up to some very large cedar elms and water oak specimens. Here is my report:
Thank you for the opportunity to inspect the trees at your home at [Houston-area residence]. As you may have learned from your research, we at Bartlett Tree Experts take a preventive approach to tree and landscape plant health, having learned in our 104+ years of operation that improving a tree’s growing conditions reduces its susceptibility to many disorders.
I’m not sure where you learned about borers, but they are not at the top of the list of priorities for your trees. Yes, certain trees should be treated prophylactically–and in some cases therapeutically–for borers, and after the heat and drought of 2011, borer populations are believed to be on the rise, so we will address those issues, but borer treatments will only be a part of the program, not the focus.
That said, allow me to observe that the species you do have are particularly susceptible to borers, especially the box elders, ash, hackberries, pecans and water oak (there are no live oaks on your property, by the way). I daresay weedeaters are a bigger threat to your trees by far than borers, but I get ahead of myself. Here is my full report:
- I counted 5 box elders, 16 cedar elms (including one very large, very nice specimen left side of house by the generator), 20 hackberries, 1 large water oak (the prime specimen on the property by far), 7 ash, 3 possum haw hollies, 2 magnolias, 3 pittosporums, 2 citrus, 54 ligustrums, 29 cleyeras, 5 Indian hawthorns, 7 nandinas, 2 Japanese blueberries, 7 Mexican heather, 8 boxwoods, 13 azaleas, a lantana bed, 3 pecans, 3 viburnums, 6 foxtails, 3 roses, 1 (mostly) dead gum bumelia, and 28 hibiscus, for a total of nearly 300 perennial specimens, not counting turf grass, clumping grasses and flowering annuals.
- The cedar elms have leaf disease and sooty mold, which is an indicator of aphids and other sucking insects. I also suspect mite damage.
- The Japanese blueberries have false oleander scale.
- The irises also have scale.
- Nearly every tree has weedeater damage, including one gum bumelia that is dead, having been completely girdled by the weedeater scarring.
- Most of the trees are small with only minor amounts of dead wood. However, the big water oak and the big cedar elm both are overdue for pruning. I recommend that they be pruned to remove all dead, broken, hanging and stubbed branches 1 inch diameter and larger, thinned to reduce weight, windsail and risk of storm damage/failure by removing approximately one fifth of foliage, taking care to prune from the ends rather than from the interior, and leave all interior foliage, including so-called “sprouts”, intact.
- Pansies should not be growing with trees and shrubs. I love pansies myself, but they need to be on a separate watering schedule.
- The lawn needs to be on a separate watering schedule as well. Trees and shrubs do not tolerate multiple waterings a week unless the soil is exceptionally well-drained. The soil can become anaerobic, increasing their susceptibility to diseases and pests, including, but by no means limited to, phytophthora root rot and the aforementioned borers.
- Every single tree, even the small ones, should have a minimum space of 8 inches separating the trunk from the nearest blade of grass. The lawn mower and weed whackers must never be allowed to contact the tree, including the root collar–the part that flares out at the base–and surface roots.
- Moreover, the more significant specimens, including the water oak and a good half dozen or more of the cedar elms, need mulch rings in the 3 to 10 foot diameter size range.
- I recommend root invigoration on the water oak and the large cedar elm. This is a procedure wherein we remove the turf grass, carefully, so as to minimize damage to the trees’ delicate surface roots, air-till the soil, incorporate compost and other amendments into the soil and cover the treatment area with mulch. It is essentially increasing the cubic footage of highly enriched growing medium and improving the tree’s overall health and ability to withstand stress. On the water oak the final mulch bed will be about 20 feet in diameter.
- I understand that my recommendations, especially Items 9, 10 and 11 have implications as to how your landscape will look, but I will be so bold as to say that nothing I noted about the place would be more important.
- The hibiscus located along the right fenceline have a lot of frost damage. Furthermore, their rootballs are partially exposed, which will further increase the numbers of those specimens that are going to die this winter. I also see some granular substance, either sulfur or fertilizer or both, resting on exposed roots. Let’s get some compost/mulch mix applied to cover all that up (again, taking care not to bury the trunks of the specimens).
- I recommend that you begin systematically planting some replacement shadetree specimens–live oak, Shumard oak, bur oak, swamp chestnut oak, Mexican white oak, American elm, Mexican sycamore, cedar elm, pecan. Do not expect anything other than headaches from your large population of ash, box elder and hackberry. You need replacement trees getting established now if you want a sustainable tree population on your property.
If you, dear reader, have a tree-related question, and you live in the Houston Area, please give us a call at 713-692-6371. Be sure to mention that you read my blog!
Bartlett Tree Experts – Houston
Board-Certified Master Arborist #NE-6315BT
Texas Department of Agriculture #0503358
The Weedeater damage, not borers, at top of list of tree problems at this site. by Gene Basler, unless otherwise expressly stated, is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.