Elizabeth Magnolia Tree leaves turning yellow/brown - Ask Extension
Lil help please
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Elizabeth Magnolia Tree leaves turning yellow/brown #476478
Asked August 07, 2018, 12:47 PM EDT
Lil help please
Hennepin County Minnesota
Expert Response
Greetings! Thank you for contacting AaE for help.
I need to ask a few questions first. Is it a recently purchased tree? How long have you had the tree planted there? Did you plant it or did someone else plant it for you? It looks like it's staked. How long has it been staked. How much sun is it getting (number of hours, morning, mid-day, afternoon)? How much water is it getting?
Your answers will help me figure this out. Thanks!
We planted an Elizabeth Magnolia tree in the fall of 2016 near where a
very old, large crabapple tree had been. We ground out the stump and the
boys chopped and chopped and chopped up the roots as best as possible
is I could turn into a perennial low maintenance garden. We added good
soil and created a slight berm on the area. The tree had to be adjusted
last summer by about a foot for various reasons for better placement and
we didn’t want the feet sitting in water. It is on the side of the berm
about half way down with good red cedar mulch in the garden bed.
It gets about 6-8 hours of sun. Very early morning and then again around 1pm-6pm.
It had a few flowers this spring and appears to have many buds growing for next year.
The question that I have is that all of a sudden the leaves have started to yellow and a few have fallen off in the past couple weeks. There is irrigation in the area by a sprinkler head but we have not gotten soaker hoses in this area yet so I have been hand watering. I have also watered the roots with a deep root waterer a couple times. The soil seems moist with the mulch. Any ideas, if it has a problem I would like to get ahead of the game as it was a gift from my in-laws.
Staking, we staked it when we planted it.
Hello,
It all sounds good so far. There are a few things we can address later but I don't think those will be the issue with the yellowing of the leaves because you haven't had the tree for very long.
You mentioned not wanting the tree to be 'sitting in water.' Does that mean that that part of the garden gets a daily watering? Also you brought in soil during the renovation. Because of these two things, I think you need to get a soil test to check to see if there is an iron or other nutrient deficiency. The cause of nutrient deficiency can be because there is a lack of nutrients in the soil but it can also be because the pH level of the soil is not right for the plant to take up certain nutrients in the soil even if there's plenty of it in the soil.
So if there's a nutrient deficiency, it could be because the watering leached it out of the soil or the new soil brought in could be of a pH level such that the Magnolia cannot take up nutrients. The U of MN Extension does soil testing and can provide answers to both questions. I've provided a link below where you can learn more about their service, prices and how to submit a sample.
If you decide to go that route, be sure to point out to them that you want to have the ideal pH level for your magnolia. For the sample take several soil samples in various depths within and just outside of the dripline of the tree, mix it up in a bucket and then take the recommended amount out for the test.
I can't be sure that the soil test will reveal the problem but it could give us a clue. So about the other things to think about regarding your tree. The photos don't show the bottom of the tree, so forgive me if I suggest that mulch should never touch the bark of trees. That's a sure fire way to rot the bark and cause serious harm to the tree. I'm sure you've got that covered (or rather uncovered.)
I also don't see if the tree is planted so that the root flare is just above the level of the ground. If the root flare is too deep the tree may eventually grow roots above the flare and possibly girdle the tree trunk. This takes time so if you find the flare low, you may see some roots starting from above it. If you correct it now, the tree will be okay. I've included a photo from pinterest.com showing a properly exposed root flare and correct mulching. Here is a link to more information about how to correct this problem should you need it from the U of Florida. http://hort.ifas.ufl.edu/woody/remove-girdling-roots.shtml
Helping a new tree get established is very important and can take several years depending on the diameter of the tree when planted. Since you planted it again last year, essentially, you've started over then. The most important thing to help your tree get established is water. I've been trying to find our article that includes a table of how much to water and for how many years based on diameter but the U of MN Extension is currently updating it's Yard and Garden web pages and it's nowhere to be found. When I find it, I'll send you another reply with that link.
On to the staking. It's important to let a young tree sway some so that the trunk can become strong. Since it is so tightly staked, I think you'll need to ease the staking off a bit by putting two stakes a couple of feet from the tree trunk on opposite sides and tying long strips of nylon hose between each stake and the tree to hold it up for another year (part way into next summer). This way the tree trunk will be supported but allowed to sway and grow stronger.
I looked up Magnolia Elizabeth and the Missouri Botanic Gardens lists its northern most zone as zone 5. The leaf problem has nothing to do with the zone but please know that a super cold winter may have a detrimental effect on your tree. Hopefully, that won't happen.
One last thing. Hennepin county has been seeing a lot of Magnolia scale in recent years. I don't see any evidence of it in the photos but it could be there and I want you to be aware of this because I haven't seen a clean magnolia for a couple of years now. Here is an article on Magnolia scale, what to look for and possible treatments because eventually your tree will probably get it. Sorry for the bad news. https://hort.uwex.edu/articles/magnolia-scale/
I hope all this information helps. If you have further questions, please reply. Your questions may actually help reveal the issue.
