Pest and Diseases on Junipers

 Pests and diseases on Junipers

by Gail Theron

Junipers are relatively tough and hardy as far as attacks from fungi and insects are concerned and this in itself creates a problem in that I tend to neglect them in any "inspection round" assuming all to be well. Because the foliage is usually quite compact and dense the "pesties" really go to town and have a ball, undetected.

The colour of the foliage is very often an indication that all is not well.

I have had the following problems:

Leaf scale

Small white scales on the upper and under surface of the leaves. Oleum or Seizer and Eco Oil is the remedy used fortnightly.

Red spider mite

A microscopic sucking insect leaving leaves looking "salt and peppered” and you will also find fine webs visible on the tree. A Seizer and Eco-oil mixture is a contact spray and applications fortnightly would be necessary. The damaged leaves will never recover.

Woolly aphids

A cotton wool and web-like appearance indicates that this is present. The same treatment as for red spider applies.  Use Koinor which is systemic and needs to be watered into the roots and not sprayed on the foliage.

Mealy bug

Bugs visible, often hide in bark in all nooks and crannies - same treatment as above. Use Koinor which is systemic and needs to be watered into the roots and not sprayed on the foliage.

Fungal problems

In recent years many Junipers overseas have been attacked by fungal problems.  We need to be alert to this and treat our Junipers accordingly with Mancozeb & Eco-oil, Rosecare or Ready to use Rose Protector.