If the juniper suddenly gets brown shoot tips, there could be various reasons. In addition to an unsuitable location, care errors, pests and diseases can cause the damage.
Why is my columnar juniper suddenly turning brown?
If a columnar juniper turns brown, the causes can be frost damage, lack of light, fungal infestation, juniper leaf miners, root damage or a high lime content in the soil. To care for the juniper, changes in location, pruning, pest control and adjusted fertilization may be necessary.
These can be causes:
- Frost Damage
- Lack of light
- Fungal infestation
- Juniper Leafminer
- Root damage
- Lime
Frost Damage
The evergreen shrubs have to maintain their metabolism in winter. When the ground is frozen and the roots cannot absorb water, drought stress occurs. The consequences will be visible next spring when the shoots have already died. Water the plants on frost-free days.
Lack of light
Potted plants often develop brown shoots if they are placed in a dark corner on the balcony. While the pots can be easily relocated, solving the light problem with overgrown specimens is more difficult. Old trees can no longer tolerate transplanting. If the bushes are overshadowed by nearby trees, only cutting these trees back will help.
Fungal infestation
While shoots only turn brown after years when infected by rust fungi, they dry out within a short time due to an infection with the fungus Phomopsis juniperivora. In this disease, also known as shoot dieback, the needles do not fall off. Affected areas should be removed and disposed of quickly.
Juniper Leafminer
The larvae of this type of butterfly bore into the shoots and eat the pulp from the inside. A clear sign of infestation are small drill holes in the brown shoots, in which the larvae pupate and overwinter until the next spring. The pest is controlled during the flight period between May and July. Spray the entire tree with a pyrethrum preparation (€9.00 on Amazon).
Root damage
Brown shoots can appear if voles or beetle larvae have damaged the roots. To discover the pests, you have to dig a small hole and check the roots for signs of feeding or rotten areas. Plant protection sticks from drugstores or garden centers can help against beetle larvae. Voles are deterred by odorous plants such as imperial crown, cross-leaved spurge or garlic.
Lime
If your old columnar juniper suddenly turns brown, the cause may be too high a lime content in the soil. Avoid lime-based fertilizers. When liming lawns, keep a distance of five meters from the juniper.
