Three Reasons Why Magnolia Buds Don't Open

Magnolia tree branch with flower buds.

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Of all the possible scenarios in which a magnolia tree is failing to bloom, perhaps the most frustrating is when your magnolia tree is producing flower buds but those buds do not open. In other scenarios, buds may not appear at all, a circumstance that may be due to improper pruning, a problem with soil pH, root damage, or the age of the plant (it simply is not mature enough to bear flower buds).

But to have your magnolia tree produce buds that never open may be worse for a gardener's psyche than any of these other scenarios, because it teases you with the feeling that you are close to success, only to suffer disappointment in the end. Let's consider three reasons why magnolia buds don't open.

Magnolia Buds May Not Open Due to Wrong Location

Magnolia trees are not difficult to grow, but they do require a few conditions if they are to perform optimally.

  1. Exposure to sufficient sunlight
  2. Soil that is kept moist but that drains well
  3. Soil with a pH that is acidic to neutral

For your magnolia tree to produce buds and have them open properly, what you have to pay particular attention to is condition #1. While magnolias will survive in partial sun, they need full sun to produce the buds that they're capable of producing and have those buds open fully during the blooming season.

Magnolia Buds May Not Open Due to Improper Care

As with almost any plant, giving a magnolia tree proper care is critical to achieving success (blooming) with it. So even if you have gotten its location right, you can still experience failure (lack of flowers) if you do not provide it with the right care afterward. Improper care can take either of two forms (active and inactive): doing something that actually harms the plant (with the best of intentions, we often give our plants too much TLC), or not doing something you're supposed to do.

Here are examples of each type of improper care, active and inactive; either may result in a magnolia tree's buds not opening:

You Are Giving Your Magnolia Tree Too Much Nitrogen

Too much nitrogen is a common culprit when plants fail to bloom properly. The problem is that a plant has only so much energy to use, and different nutrients will channel that energy in different ways. Nitrogen, one of the main ingredients in plant fertilizers, tends to channel energy into foliage production, at the expense of flower production, when applied in excess.

You Are Neglecting Pest Control

A major sub-section of plant care is pest control. Whether it be large pests such as deer, small pests such as insects, or anything in between, failure to control pests can result in plant underperformance. An insect pest to watch out for when growing magnolias is thrips. Thrips are belong to the class of sucking insects that harm plants by removing their precious juices in the process of feeding on them. Removing the juices from a magnolia bud results in its not opening. The good news is that thrips are easily dislodged from their hosts simply by turning the garden hose on them and washing them off with the spray.

Magnolia Buds May Not Open Due to Bad Weather

While you can control plant location and plant care, you can't control the weather, which can negatively impact magnolia flower production. You can do everything else right, only to have your magnolia buds not open because the weather hasn't cooperated.

The cycle of magnolia tree flower production is as follows:

  • They set their flower buds in late summer to early fall.
  • These flower buds wait out the winter.
  • They usually open in April or May.
  • In late spring and summer, the plant busily stores up energy for the production of the next batch of flower buds.

Bad weather can disrupt this cycle. The bad weather can occur in a variety of forms, from fall to spring. In fall, cold weather sometimes comes prematurely. This can result in early frosts. If a frost comes before the flower buds are ready to handle it, this can cause them to fail to open come spring.

In winter, sometimes you can have overly wet weather. This can cause magnolia flower buds to rot; rotten buds won't open. Also in winter, sometimes we have an unexpected warm spell. These higher-than-normal temperatures can result in the flower buds opening at a time when they should not be opening. When the cold weather returns, the opened buds are killed. They will not open and become flowers in spring.

Finally, even spring holds potential trouble. We sometimes get a frost when the flower buds are about to open. At this time, the moisture content of the buds rises. This moisture content is necessary for flowering, but it also makes the buds vulnerable to cold. A frost in spring can kill magnolia buds, causing them to fall to the ground, before they fully open.