So, your Laburnum Tree isn’t flowering?
Take a look at the 7 possible reasons, and decide if you can do something about this.
Why isn’t Laburnum Tree Flowering?
Laburnum Tree might not flower, because of many reasons, including drained energy, flower bud damage, or tree age.
Laburnum Tree usually flowers in May and June. Yellow flowers are densely packed in pendulous racemes 4–10 in (10-25 cm) long. The flowers are golden yellow, sweet-scented. If it’s not flowering until late spring, there has to be something wrong.
There are 7 reasons why your Golden Chain Tree might not flower. 3 of them are the most possible.
The tree might not flower because of too abundant flowers in the last season. But the reason might be also too severe frost or too early tree stage growth.
Let’s get into more details, and find out all the possible reasons.
Drained Energy
Laburnum Tree tends to flower really abundantly. Sometimes it isn’t flowering every year. The tree has a tendency to drain itself of its energy reserves whenever it puts on a good show and can take another season to stabilize again. It’s called biennial bearing. This is quite normal when it comes to this tree, so you shouldn’t be worried. The flowers might not appear at all, or might be sparse.
If the tree was flowering a lot in the last year, this year, it might need some time to recover, and flower again in the next year. If that’s the case, you might need to use a Potash fertilizer, like this one on Amazon, to prevent energy losses and reduce respiration. It should help your Laburnum Tree to stabilize energy and make it flower every year.
Flower Bud Damage
Another possible reason why your Golden Chain Tree might not flower is a too cold temperature that can damage the flower bud. The Laburnum Tree grows best in moderate climates, not too hot or too cold, preferably through 5b-7 USDA hardiness zones. It can tolerate temperatures as low as -4 °F (-20 °C).
So, if your area had a severe late spring frost, it probably damaged the flower buds and will result in no bloom this year. There is nothing you can do about this. You can plant varieties that fit your hardiness zone.
Tree Age
Ornamental trees, like Laburnum Tree, need time to mature. Some trees take 15 years, some 2 years.
Usually, you should expect the first flowering when the Golden Chain Tree is 4-6 years old. Sometimes they flower when they’re younger, but they rarely start flowering after 6 years.
So, if this year the Laburnum Tree isn’t flowering, make sure it’s old enough because it might not have reached the maturity stage yet. If it’s older than 6 years and isn’t flowering, you should look for another reason.
If you plant a seedling that you bought in the store, it’s usually 2 years old, so you should wait 2-3 years to see the first flowers.
Soil Problems
Laburnum Tree tolerates almost every type of soil, from slightly alkaline to slightly acidic. However, it does best in well-drained, moist, but not waterlogged soil. Maybe the reason why the tree isn’t flowering is too soggy soil with poor drainage.
If the tree is established and grows in healthy soil, it gets an adequate amount of nutrients and doesn’t need fertilizer. But if Laburnum Tree isn’t flowering, and you can exclude all the other reasons, adding a fertilizer high in phosphorus might help it bloom the next year. You can also apply mulch around the base of the tree all the way out to the drip line, which works as an organic slow-release fertilizer.
To determine if you need to fertilize or mulch, you should get yourself a soil test kit, for example here on Amazon. Applying a fertilizer based on guessing can lead to excessive vegetative growth, instead of flower buds, and structurally weaken the tree.
Not Enough Sunlight
Laburnum Tree might not flower if it doesn’t receive enough direct sunlight. This tree prefers to grow in full sun, or partial sun. Therefore, it should receive 6-8 hours of sunlight per day. The less sunlight, the fewer flowers.
If it doesn’t get enough sunlight, you should think of pruning neighboring plants to give your tree more access to light, or even remove them.
Wrong Pruning
The tree might not bloom because the flower buds have been accidentally removed when pruning. If you prune too heavily, you will get a lot of vegetative growth.
You should only trim off dead, damaged and unattractive growth during any season. Also, leave the suckers in place for a thicker, shrub-like appearance.
Trees can bloom on old or new wood, and must be pruned accordingly. The correct timing is also crucial here. Prune your Laburnum Tree in summer, after all blooms have faded.
Not Enough Water
Insufficient moisture can affect the flowering of the Golden Chain Tree. If there is a severe, extended drought when trees that bloom on old wood develop their buds for the next season, and they aren’t given extra water, they might not bloom the next spring. To prevent this, make sure to water the tree during a drought.
The Golden Chain Tree has medium moisture requirements, and it is fairly drought tolerant, but make sure to water it during extended drought. Also, be sure the water doesn’t puddle at the base, since it doesn’t do well in standing water and is particularly susceptible to root rot that might result in no bloom.
Sources
thespruce.com, gardeningknowhow.com, ehow.co.uk, plants.ces.ncsu.edu