Full of anticipation for the splendid spring blooms that these flowering trees bring year after year, many a disappointed gardener has been forced to ask, "My magnolia buds are not opening for some reason this spring; is it due to frost damage?" One gardener, in fact, wrote in with just such a question:
"We have an older northern magnolia tree (we live in northeastern Indiana). It is healthy and had produced beautiful blooms in the spring.
However the past three springs the tree will bud with blooms but the buds do not open. The first year I believe it happened due to a killing frost. Then last year I assumed the same. However, I noticed other magnolias in our area in full bloom. Again this spring, the bloom buds seem to be closed while others in our neighborhood are opening. What could be the reason? Is it frost again?"
Why Flower Buds Are Not Opening on Your Magnolia Tree
First of all, note that a magnolia tree will have two different kinds of buds. The flower buds are bigger and are supposed to open earlier. The smaller buds are leaf buds; those pop open later in the season. Both somewhat resemble the catkins on pussy willows.
A number of problems are potential culprits when magnolia buds (either for flowers or for leaves) are not opening. One possibility is that thrips are attacking your magnolia buds. But weather comes to mind, first and foremost, as a possible reason for the failure.
What kind of spring weather did you have in the Midwest this year? Here in New England it has been a cold, damp spring. Magnolia buds can rot during extended periods of such weather, and once rot sets in, the buds will not open.
Also, do not rule out frost as the culprit last year just because your neighbors' magnolia buds opened up into flowers.
Frost is a surprisingly localized phenomenon. Homeowners observe that some specimens will avoid frost damage in one area of their landscaping, only to discover that the very same type of plant in another part of the landscape has succumbed to the frost.
The possibility that bad weather (whether it be frost, cold temperatures, or damp conditions) is to blame should logically occur to the gardener's mind first, because magnolia trees set bud in fall. That means that there is a lot of weather -- much of it bad, in the North -- for those buds to wait out before it is time for them to open in spring. They are at the mercy of the weather for all of that time. For example, if the flower buds should open prematurely due to unusually warm weather in winter, and then normal winter weather comes back with a bang, you will lose the flowers. In other words, the actual flowers are unable to withstand wintry conditions that the unopened buds are usually able to withstand just fine.