Question
Very large beautiful magnolia tree in front yard in Austin TX.
It does not produce many white flowers.
It seems the white flower turns brown before it is fully opened.
There are large white or silver spots on the trunk and large branches.
Has many brown leaves on the tree that fall off year round.
In years past it produced many beautiful white blooms.
Any help or advice you can give would be appreciated.
Jerry

Answer
More likely, the plant is missing some essential trace elements, or micronutrients. Nitrogen-rich soils encourage trees to produce more vegetative growth and fewer flowers, and the fertilizer for laws contains a good deal of Nitrogen. I think you need more phosphorus and micronutrients to stimulate root growth and flowering. Scatter the fertilizer around the tree at the rate of 1 lb per inch of trunk diameter --apply in the spring every 4 weeks for 3 applications. Use  add super phosphate (0-20-0) and your recommended micronutrients according to the directions on the bags. A fertilizer called Holly tone will work well. Use it this fall and again in the spring.
May check with your garden nursery they may have a fertilizer for magnolias or flowering trees.


Magnolia trees hold their leaves throughout the winter, shedding old leaves in the spring through the early summer to make way for new leaf growth. This is their normal pattern and not evidence of disease or pest infestation. They tend to shed leaves during the growing season and the raking of leaves can become a problem.

The white spots on the trunk are lichens and are not a health problem to the tree.

Lichens are an example of a symbiotic relationship between algae and certain fungi. They are capable of producing their own food. The algae associated with the fungus is a green or blue-green alga. There are three forms of lichens based on growth patterns. Crustose are species that are closely pressed against the surface of the limb or trunk of dead or live trees. Foliose forms are leaf like or prostrate but are also tightly attached to the tree. Fruticose forms are bush like, erect or hanging. Although lichens are found in most areas of Texas, they are most noticeable in areas that have extended periods of high humidity.

The effect of lichens on a tree are only slightly detrimental. The plants are epiphytes. That is they derive their nutrients from the air and not from the plant on which they are growing. Although they are not parasitized, literature reports suggest that lichens do have a slight negative effect. The main concern is that lichens give a tree an unkept appearance. Presence of lichens also is a good indicator of a thin tree canopy. This often leads homeowners to conclude that lichens are the cause and not the effect of thin foliage. The best control for lichens is maintain the tree in good condition. This will insure a dense canopy which will shade the limbs and reduce photosynthesis. Without photosynthesis, lichens are not able to manufacture food needed for growth and development.