Does my oak tree have a disease?

[K-AngeL]

I have quite a large oak tree in my back garden and it is covered in white patches. The older bark on the main trunk doesn't seem to have them but it is present on all the upper branches. I have attached a couple of photos so you can hopefully see what it's like. What I'd like to know please is whether or not it is a disease. If it is diseased is it serious and can I do anything about it. I have a few other smaller oak trees in the garden so I'd also like to know if it's contagious and if I need to do anything as drastic as chop down the tree (I hope not). Thanks.

[Arborist]

Pruned... Its been topped! Looks ok though

[Chris P]

Thought it had been hit hard.

 

Its not going to win the perfect Oak 2010 Competition but a little bit of deadwood removal and the odd gander every year wouldnt go amiss.

 

Better to have it then to not.

[stoxs]

Thought it had been hit hard.

 

Its not going to win the perfect Oak 2010 Competition but a little bit of deadwood removal and the odd gander every year wouldnt go amiss.

 

Better to have it then to not.

 

 

well spotted, massive bark change at one point, pollarded about 20-25 years ago?

 

Bit of trimming up and a crown thin it would look o.k

[Andrew B]

If no-one is going near it, then I would let it runs it own course for a few years.

[tommer9]

Its growing sideways for starters, that cant be helping lol!

[K-AngeL]

What difference does it make if anyone is going near it? Branches dropping off or summat? I didn't think oaks were prone to that. We do go near it and will be going even nearer to it soon to sort out the rest of the hedge either side of it and the stuff thats growing round the base.

What is the best time of year to sort out taking off the deadwood and thinning the crown please? Glad theres nothing major wrong with it.

[Mesterh]

What difference does it make if anyone is going near it? Branches dropping off or summat? I didn't think oaks were prone to that. We do go near it and will be going even nearer to it soon to sort out the rest of the hedge either side of it and the stuff thats growing round the base.

What is the best time of year to sort out taking off the deadwood and thinning the crown please? Glad theres nothing major wrong with it.

 

Ie leave the deadwood if its not a problem, it might fall off and hit you.

 

Deadwood anytime but may as well wait until the summer to do any pruning of live wood.

[Jane_Whitt]

Root system

 

Our native oaks have developed adaptations to survive the long summers, dry most of California. Senior survival is the development and characteristics of its root system. When an acorn sprouts first, there is a rapid development of roots and very little growth above ground. This initial root is a taproot extending to great depth of reliable moisture. In fact, the tree of the early focus on establishing a maintenance system with deep roots. Once this has happened, more foliage on the ground and the growth takes place. As the oak grows, the root is cured with an extensive system of lateral roots extending horizontally from the trunk to and beyond the drip line, sometimes as much as 90 feet. For a mature oak, this horizontal root system is the mainstay of the tree to the rest of his life. Includes very important roots that absorb moisture and nutrients. Most of the roots occurs within three feet of soil. In shallow soil, root system is concentrated in one area even more superficial, one to two meters below the surface. As a mature oak, especially in areas naturally dry in summer, deep vertical growth of the roots of the shape of the sides, usually within ten feet of the trunk. These roots lead exploit more soil moisture and stability to an increasingly massive tree. By the time a mature oak has established its root system so elaborate and designed for your environment and particular site conditions, which has lost the vigor of youth. It is less tolerant of changes and less easily retrieved to support a fully developed structure of life. To protect a mature oak, with special attention to drainage, and avoid filling, trenching, or paving near the root zone.

 

IRRIGATION

 

Native oaks require little or no supplemental irrigation generally healthy and stay on dry soils.

 

COVERS

 

Earth and other materials placed on top of natural ground level, called fillers, are usually packed. They make the soil less permeable, which restricts or prohibits the exchange of gases and water movement. Excess moisture trapped by filling and also the root cause crown rot. Because there is no guarantee that full security can be added with about an oak, it is best to avoid manipulation of the natural grade, or to leave the natural grade in the root zone alone and use retaining walls .

 

Optimal treatment under the tree is to place a 4-inch layer of shredded bark mulch on the soil surface. Ideally, the least expensive, pieces of bark contains a wide range of particle sizes up to 2.3 inches of sawdust pieces. Less effective and more expensive, bark mulches have been selected for a uniform site, may come from recycled wood chips or strips are made of redwood bark, and these are not generally recommended. Place no more than 4 - inches and not immediately put in the trunk.

 

LANDSCAPING

 

If under oak landscape you want to be kept to a minimum to avoid a negative impact on tree health. Avoid extensive landscaping, lawn, especially the herbaceous ground cover, annual and perennial flowers that require heavy irrigation. Select your place plants that tolerate shade and dry soil conditions. Many beautiful species of native plants and species from other Mediterranean regions of the world, will thrive in these conditions. Do not water the plants or within 10 feet of the trunk, under any circumstances. Between 10 feet and the edge of the plant canopy drip line to use accents in place of cover crops. Drip irrigation just to get new plants established, and only then periodically during the warmer summer months. An ideal development scenario includes the installation of the plants in late fall and root systems to establish in the winter months. During the first growing season using drip irrigation system for watering at least three at a time possible a month or less. In the following years a month or less watering during the hottest months is to keep plants healthy, vigorous and attractive if they have been carefully selected.

Paving and soil compaction on the root system can be extremely harmful and can cause distress and decay. The covers are an excellent way to create a usable outdoor space under native trees.

 

FERTILIZATION

 

Native oak trees rarely require fertilizing, especially if they have been bitten. If the foliage is mottled, or lacks a deep green, light fertilization with nitrogen fertilizer can be beneficial. Soil testing by a local soil laboratory testing is the best way to determine soil fertility.

 

PRUNING

 

Pruning is not usually necessary in native oaks, except to correct structural problems or to remove dead wood. The elimination of more than 10% of live foliage at any given time can be detrimental to the tree. Excessive pruning or thinning of the extremities can expose inner branches of the damage the sun can stimulate the tree to produce new succulent growth that is subject to mold, and in some cases, can cause a decrease in force or can kill a tree. Only dead branches, weakened, diseased or dangerous should be removed. Pruning must be done during the winter dormant. Robles have been pruned by a qualified arborist certified to maintain their health and structural integrity.

 

SIGNS OF TROUBLE

 

Any of the following symptoms may indicate a serious problem.

If you notice any of the following symptoms, contact a trusted arborist to determine a course of action:

• thin cover or open, sparse foliage, fall foliage

• mottled yellow and small foliage

• dead or dying branches or foliage

• dense and short shoots on branches and / or trunk

• caries or cavities in the trunk or large branches

• yeast stops working, mushrooms shelf in the trunk or root collar

• wet patches, pus, or mucus in the trunk or limbs

[Fungus]

1. When an acorn sprouts first, there is a rapid development of roots and very little growth above ground. This initial root is a taproot extending to great depth of reliable moisture. In fact, the tree of the early focus on establishing a maintenance system with deep roots. Once this has happened, more foliage on the ground and the growth takes place.

2. As the oak grows, the root is cured with an extensive system of lateral roots extending horizontally from the trunk to and beyond the drip line, sometimes as much as 90 feet. For a mature oak, this horizontal root system is the mainstay of the tree to the rest of his life. Includes very important roots that absorb moisture and nutrients. Most of the roots occurs within three feet of soil. In shallow soil, root system is concentrated in one area even more superficial, one to two meters below the surface. As a mature oak, especially in areas naturally dry in summer, deep vertical growth of the roots of the shape of the sides, usually within ten feet of the trunk. These roots lead exploit more soil moisture and stability to an increasingly massive tree.

 

Jane,

1. An acorn has an energy reserve for 3-5 years and has to associate within that period with a pioneer ectomycorrhizal macrofungus or a symbiont (still) attached to secundary roots of the "mother" tree, to develop a primairy root system, that is supplied with water and nutrients by the mycelium of the ectomycorrhizal symbiont, and to develop foliage to produce its own energy, or else the seedling will die.

2. Never heard of the dynamics of and succession in the life cycles of tree species specific ecosystems, their soil food webs and the dominant tree species specific ectomycorrhizal macrofungi, on which the tree depends for water, nutrients and minerals such as phosphorous (reproduction : DNA), for protection of their roots against parasites, drought, salt, toxic metals and for sudden temporary temperature or pH changes, play in them ?

[Tony Croft aka hamadryad]

Im glad you said that!