Seeing white powdery growth on leaves and shoots in your garden or landscape? It's probably a sign that you have a common disease called powdery mildew. Powdery mildew occurs on many different plant species including fruits, vegetables and ornamentals, and may be caused by several different fungi. Symptoms vary by plant species, but infections on most plants start as white powdery spots that expand on leaf surfaces or buds. Leaves often turn yellow or brown and fall off. Vegetable fruits are usually not affected, but apples, grapes and stone fruits can develop russet scars or corky areas. In some plants, powdery mildew can cause distorted growth.
Unlike many diseases, powdery mildews generally do not require moist conditions to...
- Author: Igor Lacan
[From Dec 2013 issue of the UC IPM Green Bulletin newsletter]
Pruning in Practice
Pruning is perhaps the most common tree maintenance activity that is undertaken on urban and ornamental trees. This is in sharp contrast with forest trees, which are pruned only in exceptional cases and yet grow and develop their mature form quite well, living considerably longer than urban trees. This tells us that trees do not require pruning in order to survive. Nevertheless, in ornamental landscapes, pruning can be beneficial for maximizing the benefits of trees, and in young trees pruning.../span>
- Author: Karey Windbiel-Rojas
The western boxelder bug (Boisea rubrolineata) usually feed on the leaves, flowers, and seedpods of the female or seedbearingbox elder tree and occasionally occur on mapleand ash trees. They sometimes feed on certain stone fruits and on grapes, where their feeding punctures cause the fruit to become deformed. Large numbers of the bug usually occur only on female box elder trees.
While boxelder bugs do not cause significant damage to landscape plants, but they may become a nuisance by invading homes in the fall in California. If boxelder bugs become a problem, seal up entry points such as cracks and screen windows and doors, and eliminate hiding places and debris outdoors.
Boxelder bugs are sometimes confused with other...
- Author: Andrew Sutherland
[From the June 2013 issue of the UC IPM Retail Nursery & Garden Center News]
Many gardeners are adding fountains, ponds, and other water features to their landscapes. Water gardens (Figure 1) are beautiful and calming, but, if not managed properly, can add an unpleasant element to the landscape—mosquitoes. How can you manage water features to prevent mosquito infestations?
First, it is important to understand mosquito biology. Mosquitoes are small flies that lay their eggs in, on, or near stagnant water. The larvae, or wigglers, (Figure 2) that hatch from.../span>
Have you seen large black or golden-brown bees foraging in your garden? These could be carpenter bees. Carpenter bees bore into lumber or trees to make nests for their brood and can damage structural wood or leave unsightly holes and stains. Multiple bees may use a common entry hole, tunneling several feet into wood to create chambers for their offspring, and the sound or sight of these large bees may be disturbing to some people. However, carpenter bees are considered mostly beneficial because of their role in pollination. Males can't sting and females rarely do.
Prevention is the best approach for management. Use hardwoods in structures where possible and paint or varnish exposed surfaces. If you find carpenter bee holes and...