Usually they are the most beautiful feature of the Japanese umbrella fir. They are shiny, dark green, leathery and stand together in umbrella-like structures. But when the approximately 10 cm long needles suddenly turn yellowish, the carelessness is over.
Why does the Japanese umbrella fir have yellow needles?
Yellow needles on a Japanese umbrella fir can indicate drought, a lack of nutrients, the wrong location or a spider mite infestation. The remedy is sufficient water, bark mulch, balanced fertilization, location adjustment or eliminating spider mites.
The environment is not right
The most common reason for yellowish needles is dryness. The Japanese umbrella fir depends on a lot of moisture. Since it has shallow roots, it cannot reach the groundwater and relies on water from above. Persistent dryness means stress for them and as a result the needles turn yellowish.
Umbrella firs in pots are particularly at risk. Here you should be careful that the root ball never dries out. For Japanese umbrella firs outdoors, you can mulch the root area as a precaution, for example with bark.
Far more rarely, this plant is too wet and suffers from waterlogging. Waterlogging and associated rot can also lead to yellow needles. Prevent this by planting your coniferous tree in permeable, medium-heavy soil!
The nutrient balance is unbalanced
The nutrients can also play havoc with the Japanese umbrella fir:
- Overfertilization: Needles inside the conifer first turn yellow and later fall off
- Potassium deficiency: This occurs quickly when there is too much rain (washout)
- Nitrogen deficiency: associated with poorer growth
- Lack of trace elements such as magnesium, boron, iron and zinc
- Soil contains too much lime
- if applicable Fertilize once a year with fir fertilizer (€9.00 on Amazon) or compost
The wrong location was chosen
The following location characteristics can quickly make a Japanese umbrella fir look old/yellow:
- too much warmth/heat
- too much sun, especially at midday (sunburn, needles dry out)
- too dry air
- Soil contains too much lime, is too clayey and too heavy
A spider mite infestation
In rarer cases and more often in container culture, a spider mite infestation leads to yellow needles. These animals suck out the needles on the underside. Over time, the needles lose so many nutrients that they bleach. A strong shower helps to remove the spider mites.
Tip
If nothing is changed in terms of location or care, the yellow needles are often followed by brown needles, which will soon fall off or should be cut off.