Tree of the month
Cucumbertree Magnolia • Magnolia acuminata
Gilbert A Smith, ISA Certified Master Arborist
It’s a funny sounding name that doesn’t really capture this tree unless, of course, you’re just looking at the flowers and fruit, which must have been what the botanist that named it was looking at. The hardiest of all the Magnolias the flower isn’t showy, white or pink the way you’d expect. Flowers born on the upper parts of the tree, which grows 60 to 80 feet, you generally don’t know that you are looking at a magnolia at all. If you look real hard the fruit does look a little like a cucumber. I recommend it as a replacement for Ash trees and it’s among the best.
An ancient species that grew up with the dinosaurs, it has simple insect pollinated flowers. It’s believed that the magnolia species evolved even before the honey bee, so a beetle likely spread its pollen. The vast majority of street trees in the Chicago area evolved later and are wind pollenated. Don’t miss the significance of this, because it means the magnolia is non allergenic. Most tree allergy sufferers don’t react to this tree.
Because it is not a familiar tree like a Maple or a Linden it doesn’t get over planted and so there are very few insects or diseases to mar those large, clean, dark green leaves. This Magnolia likes room for its roots to grow, sunlight to feed itself and that’s all it takes to grow a 60 foot tall specimen tree in no time at all. A native throughout the midwest it is endangered in Canada where it is protected. The Shining Tree woods in Norfolk County, Ontario is one of the few places left where a high concentration of Cucumbertree Magnolia exists. The average age is 120 years. The oldest Cucumbertree Magnolia lives in North Canton Ohio is 433 years old, 96 feet high and its trunk is almost 8 feet wide.
You can see lovely specimens at the Chicago Botanic Gardens overlooking the Great Basin just past the sensory garden. You might have to special order this tree for spring planting which may seem like an inconvenience. It’s actually an advantage because like a rare dog breed it has not been overbred and therefore has resistance to common problems associated with overbreeding. Also you have the privilege of preserving an endangered species and being a collector of rare treasures.
I’ve got bugs on my trees, what should I do?
Gilbert A. Smith, Master Arborist
Oak galls, nipple galls, ants, grubs, petiole gall, canker worm, fairy ring, root rot, fire blight, you’ve got them all! Taking a gentle turn around your garden turns into a fit of fear that your yard is infested with diseases, weeds and bugs. A bag turns up at your door with something crawling inside and the alarming warning, “Look what I found on your trees!” Reading your favorite gardening magazine you have probably been warned about some coming scourge on tomatoes or infestation in your raspberries. If you are a normally sensitive home owner you are probably wondering if the world will ever survive this onslaught of bugs.
This month I’m writing to calm your nerves. Every year in July we are bombarded with questions about holes in leaves or unusual colors on leaves or tree trunks. Here’s the good news, for the most part they are normal, natural and healthy.
I need to really emphasize this! Insects, fungus, bacteria, virus, and weeds are all a healthy part of nature. To find them in your yard is a good sign, not a bad one. If you look into your landscape and you don’t find any of these natural organisms, then you are really in trouble.
I’m telling you this because I suffer from the same malady of seeing only the weeds and bugs and missing the beauty all around me. Lesley and I, two certified arborists can hardly enjoy a romantic evening at Ravinia without mentally trimming the trees. However, I want you to enjoy your trees this summer and not fret over them. Certainly there are many problems that deserve our attention, but the ones that we most often get calls about ain’t them. And beware of advertisements or solicitations trying to sell you a pesticide that will cure all your problems. Those are the really bad bugs!
I don’t want you to stop calling us when you see something unusual. We know what to look for that really needs attention. That’s why we’re here, to help connect you to nature and so that when you stroll through your landscape you know that it’s being taken care of. All you have to do is enjoy this wonderful gift. Click here for a printer friendly version of the article
Mother Nature's Moment
Lesley Bruce Smith, ISA Certified Arborist
This summer has been a record breaker for folks asking us for good suggestions to replace their dead or dying Ash trees. A sad discussion, always because it implies they have lost a tree, but hopeful because it has provided an opportunity to increase the diversification of our urban forests by planting a new tree that is not as common and will have a greater chance for long term survival.
Urban trees already have lots of strikes against them due to the difficult circumstances of living in and around people. However, we don't have to add insult to injury by planting lots of replacement trees of the same species creating the setup for another catastrophic loss like what has happened with our beloved American Elms with Dutch Elm Disease, so named because the fungus that carries the disease arrived on the feet of a little beetle from Holland. Or the current heartbreak of Ash trees with Emerald Ash Borer, which probably arrived in shipping pallets that were brought from Asia carrying auto parts into Michigan. Something that many people do not realize is trees are propagated asexually. That means, in effect, that we create millions of clones that are susceptible to devastating and catastrophic loss if only one weakness in that species is found. The sad news or the good news, depending on one's perspective, is that nature is always looking for opportunities to exploit weaknesses.
Did you know that many of our Chicago suburbs have lost over 50% of their urban canopy due to over planting of Ash trees? Gil and I are desperately trying to spread the word to not plant too many of any one species again, so we do not have to repeat this sad event. When we were young, our neighborhoods were lined with American Elm trees and when they were all removed, our communities replaced with too many Ash trees. Yet, we see so many Ash being replaced with Maples, Maples and more Maples...with maybe a few other options. Please check out our list of Ash replacement trees so that we can all help to be part of a solution, instead of creating this heartbreaking event, yet again. Pick a tree you have never heard of before and go the extra mile to find and plant that, so you are a giver to the next generation as a species diversifier!