Question
Oak Upper Crown
Hello and thanks in advance for the info!
I live in Central Florida and recently bought a house on a corner lot with a large number of wonderful old shady oaks, I am thinking they are live oaks and water oaks. There are also numerous other trees including pines.
I have one live oak that i am concerned about. It has lost many leaves at the crown, but the bottom limbs seem fine right now. The crown is not completely bare but is close (see attached photo). There is also a foamy sap coming out about 6 feet from the ground and dark sap coming from a number of places and heights up to 15-20 feet running down the trunk. A couple small black bugs (beetles) have found the foamy sap. There is also a small (maybe 1 ft long) web area about 15 feet up the trunk. I have photos of these things too that I can provide on a follow up if you like.
I have looked online and have found such things like oak wilt and SOD but being in central florida it doesnt seem likely. None of my other trees seem affected at this time.
Thanks VERY much for your help. I really hope to keep this great tree.
Dave
AnswerSend the other pictures if you would. You can send them to my e-mail
[email protected]. OR attach them here but I think you can only attach one picture at a time to a question .
It is not SOD or oak wilt. More than likely a combination of several diseases--slime flux, and hypoxylon canker and maybe a borer. All these are associated with a tree under stress. The pictures will help a lot to ID the problems.
I would start by fertilizing the tree with 10-10-10 fertilizer at the rate of 1 lb of fertilizer per inch of trunk diameter scattered around the tree and watered in good. Apply just before a rain storm and you will not need to water. Make sure you do not use a fertilizer on the lawn called Weed and Feed--these type fertilizers contain a herbicide and can cause the trees to die.
Thanks for the pictures they did help. The dark areas are the result of a borer entering the trunk and the tree trying to keep the insect out by exuding sap. The white froth is slime flux.
A good spray for borers is one called Merit or Onyx. These are sprayed on the trunk and are absorbed into the wood killing the borer. A soil applied insecticide that should work is Bayer Advanced Tree and Shrub Insect control. This is applied to the soil and the roots transport it into the trees system killing any insect attacking the tree. It is good for large trees where you can not reach the trunk. Here is a web link to this product--Check with your local nursery for these products. http://www.bayeradvanced.com/product/Tree-Shrub-Insect-Control/concentrate.html
As I said usually borers attack trees under stress so I would recommend that you fertilize the tree with 10-10-10 fertilizer at the rate of 1 lb per inch of trunk diameter scattered around the tree and watered in good. This will increase the health of the tree.
The white oozing is slime flux. Wetwood and slime flux are poorly understood tree disease problems. Wetwood is an internal bacterial infection in the wood of host trees. Slime flux is an external bleeding of sap typically associated with such infections. Concern is sometimes justified as wetwood and slime flux can cause noteworthy debilitating effects on infected trees including some dieback or decline, and an inability for wounds or pruning scars to form callus tissue for healing.
Recognition: Wetwood and slime flux are most often recognized by the oozing, bleeding, or fluxing of sap from bark fissures, pruning scars or wounds on the stems or branches of infected trees. Fluxing often occurs in branch crotches resulting from the tearing of tissues at these junctures by excessive branch weight, wind, etc. The oozing sap is usually dark brown, frothy or slimy and foul smelling soon after it is exposed to the air due to the activity of certain bacteria, yeast and other fungi by which it is rapidly colonized - hence the name slime flux. Slime flux, when profuse, characteristically flows downward from its points of emergence, and upon drying leaves a light gray to whitish incrustation on the surface of the bark. Due to its oftentimes highly alkaline nature, slime flux frequently results in the death of turf, shrubs, and plants on which it drips beneath infected trees.
The bacteria associated with wetwood and slime flux are common soil and water inhabitants. These organisms presumably gain entry into susceptible stem-wood tissues through wounds or pruning scars via certain insects, pruning tools, birds, and wind. Additional infections appear to be possible through direct root penetration or colonization of root wounds. Once established within the host the bacteria multiply and colonize the tree's central heartwood core. To a limited extent, the bacteria may also colonize portions of the outer, sapwood tissues. The metabolic activities of the bacteria within infected wood tissues generate a variety of gases, predominantly methane, nitrogen, and carbon dioxide. These gases, when confined within the wood tissues, produce unusually high pressures which force the sap outward through wounds and branch stubs giving rise to the readily identifiable, external slime flux.
Control: Control of wetwood and slime flux in forest tree stands is impractical. Infected ornamental trees may be helped by pruning declining branches, and fertilizing to promote tree vigor and wound closure.
There is no known effective control for slime flux. Preventative measures such as avoiding moisture stress, proper pruning and adequate fertilization may help invigorate trees. Again fertilizing will help increase the overall health of the tree.
So I would spray the trunk with the Onyx or Merit or use the Bayer product for the borers and fertilize the tree with the 10-10-10 fertilizer. Web link to Bayer product. http://www.bayeradvanced.com/tree-shrub-care/products/12-month-tree-shrub-insect...
Here is a good web link for grass in Florida. Generally it needs 1 lb of nitrogen per 1000 sq feet of lawn. Check with your local garden store for a fertilizer for St Augustine.
http://edis.ifas.ufl.edu/lh010
