Knowledgebase

Well established Tulip/Magnolia tree didn't leaf this year #575029

Asked June 28, 2019, 2:52 PM EDT

I have a 30-40 year old well established Magnolia tree that didn't leaf out this year. The tree blossomed and had a great leaf canopy past years including last year. Buds are present on the tree, but they're dry and disintegrate when rubbed between fingers. I had a certified arborist out this week, and he was stumped. He said the tree looked healthy otherwise, with green wood, and no indication of fungus/black streaking. He thought perhaps it had been infected with a virus, but he'd never seen another case like this. Main question - is there something further I can do, or shall I just wait until next year to see if it blossoms again?  How will I know it it's dying and should be taken out?

Multnomah County Oregon

Expert Response

I'm sorry about your Magnolia. It is very distressing when a seemingly-healthy tree suddenly fails. Since you have had an arborist look at it (a smart move), I'm sure he eliminated many of the possibilities. If it was just the buds that were dry and dead, it would strongly suggest freeze damage, but lack of leaves indicate something more widespread.
Here is a link to an article that pretty much covers the possibilities: https://extension.oregonstate.edu/news/how-examine-deciduous-tree-leaf-out-problems
Are there any leaves at all? If so, do they look healthy, or are they stunted in some way? If there are some branches with leaves and some that are dead, a disease is likely.
You can examine the buds more closely to determine when they died - if they are brown all through, they have been dead for awhile. Also you can examine the cambium layer (just below the outer layer of bark) on several branches to see if it is still green, or brown and dead. If many branches still have a green cambium, then there is hope, and you should just wait and see what the tree does over the next couple of months. On the other hand, if there is widespread cambium death, it is probably a goner.
Unfortunately that is sometimes the way trees go. It may have been stressed (by heat, drought, root rot...) for many years, but still managed to bloom enough that you didn't notice. Often a tree that is dying will have a spectacular bloom the last year before it dies (an effort to propagate itself). It seems to use the last of its energy for that.
Another thing to examine is whether there has been in significant change in the growing conditions around it in recent years. A construction project that might have damage roots? A decrease in watering that might have stressed it? Over-zealous spraying of herbicides that might have poisoned it?
If you choose a new tree to replace it, try to match its requirements to the growing conditions. It also wouldn't hurt to dig up some of the roots of this tree and see if there are any signs of rot or disease. Is so, you shouldn't plant another Magnolia in the same area.
Best of luck.



Signe Danler, Online Home Horticulture Instructor Replied June 29, 2019, 2:26 PM EDT
A new interesting twist to my non-leafing Magnolia tree.

The top 20% of the tree (along newer growth branches) is not leafing.  In addition, there are leaves sprouting along it's trunk, from top to bottom.  The leaf buds on the older branches remain dry and crumbly (of which there are a normal amount)

Does this mean anything?  Would watering/fertilizing at this point help?  The tree is on a slope, and soil is pretty compacted around the base - should I loosen it up, or otherwise "inject" water and/or food into the soil?

Thanks!
Scott
The Question Asker Replied July 22, 2019, 2:57 PM EDT

It is possible your tree was affected by a spring frost. If magnolia trees have been subjected to cold temperature conditions, wait until warmer spring weather to more accurately assess the damage. If the correct magnolia cultivar has been planted for the local climate, it is likely the freezing temperatures have caused only superficial problems. Once temperatures warm, clear away dead leaves and flower blooms to examine stems and branches for deeper damage like frost cracks. Prune away any damaged or dead wood. Apply a light fertilizer and mulch, which will help the tree recover and prevent frost from reaching the magnolia's roots in the future. The mulch will also help your compacted soil condition and improve water penetration. Small frost cracks rarely require treatment; larger ones, however, should be treated with fixed copper.

The best way to avoid or minimize cold temperature damage to magnolia trees is to plant cold-hardy varieties. For example, Star magnolia is well known for its resistance to winter cold and grows well in USDA zones 4 through 8. Saucer varieties (M. x soulangeana) are also popular magnolia tree owing to their prolific flowering displays; they too are cold hardy and can be planted in USDA zones 4 through 9. In areas susceptible to late frosts, select the later-blooming cultivars “Lennei” or “Alexandrina.” Magnolia hybrids such as “Betty,” “Pinkie” and “Ricki,” created by crossing M. liliiflora with M. stellata, display cold resistance to USDA zone 5, and are also later bloomers, making them less susceptible to late frost damage. If you are set on planting a Southern magnolia (M. grandiflora) in a colder region, “Bracken's Brown Beauty” is cold-hardy variety.

When planting magnolia trees, select sites that have full sun, well-drained soil and are shielded from gusty winds. Avoid excessive use of nitrogen fertilizers and over-watering in late summer; doing so encourages new growth that will not sufficiently harden off before winter, making cold temperature damage likely. In colder climates, plant new trees when dormant in early spring.

Branches failing to bud out are also a symptom of problems including severe root rot, an infestation of root weevils, insects girdling the branch, and many other factors.

Here is a publication you will find useful:

https://gardenerdy.com/magnolia-tree-diseases

Hope this helps!

 

Chris Rusch Replied July 24, 2019, 11:58 PM EDT

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