First the needles turn yellowish and finally take on a brown color. If they are brown in color, it won't be long before they fall off. A cause for great concern or can the Colorado fir, which is one of the popular Christmas trees, still be helped?
Why does Colorado fir lose needles?
The Colorado fir loses needles due to care errors (dryness, lack of nutrients, over-fertilization, waterlogging), unsuitable locations (too much sun), diseases (pine canker, pine needle rust, gray mold) or pest infestation (spider mites, wreath weevils, lice). If you are ill, diseased needles should be disposed of with household waste.
Maintenance errors as a cause
Maintenance errors are most often the cause of increased needle shedding in Colorado fir trees. Most often it is dryness. If there is heat in summer combined with prolonged drought, the Colorado fir suffers if it is not additionally watered. Young specimens in particular should be watered abundantly.
The following points can also be the cause: lack of nutrients, over-fertilization and waterlogging in the root area. If there is a nutrient deficiency, fertilizing with Epsom s alt (€9.00 on Amazon) helps, as it contains magnesium, which is essential for Colorado firs. If there is over-fertilization and waterlogging, you can transplant young specimens. There are no other options in these cases.
Inappropriate location as a cause
Colorado firs prefer to be in a location where they can find both light and shade. Therefore, partially shaded locations are ideal for them. They do not feel comfortable in the blazing sun, for example in a sheltered south-facing location. Young Colorado firs in particular are at risk for sunburn. The needles turn yellow, brown and eventually fall off.
Illnesses as a cause
Incorrect care or an unsuitable location do not always have to be behind the needle dropping. It may also be that your Colorado fir is sick. It is usually considered to be less susceptible to disease. But sometimes the following diseases can strike:
- Fir crab
- Fir needle rust
- Gray horse
Pests as a cause
In dry periods, trees such as the Colorado fir are prone to pest infestation. The tree is weakened and its defenses are no longer effective. Check the crop for pest infestation!
Among other things, spider mites can make life difficult for the Colorado fir tree. But the black-spotted wreath weevil also knows how to put its biting tools to good use. On top of that, lice such as the pine trunk louse or the cinare bark louse can appear and suck out the needles.
Tip
If the cause of needle shedding is illness, it is recommended to sweep up the diseased needles and not dispose of them in the compost, but in household waste!