Are you one of the many businesses looking to do your part in reducing water use during Southern California’s severe drought conditions? Every little conservation step you take helps support a more secure water future. Arborwell’s San Diego consulting arborists are here to help you achieve your goal of creating a more waterwise landscape with this list of drought-tolerant trees for Southern California.
California’s extreme drought conditions have made water conservation a common goal for the region’s businesses. Choosing drought-resistant plants and trees makes achieving this objective easier while keeping your commercial landscape looking great. Fortunately, Northern California’s warm climate and long growing season give trees ample time to get established before the first December frost, making now a great time to contact our tree management team about making the switch. What do our arborists recommend for landscape trees for drought conditions in Northern California US Hardiness Zone 9?
All trees need water to survive. Each species requires a specific amount and frequency for optimal health; however, location, environmental conditions, and weather directly impact these needs. For this reason, drought can be especially dangerous for urban trees outside the natural forest setting, making meticulous tree care during a drought essential. How can you keep your commercial landscape’s trees looking their best?
Over the past several years, Seattle’s weather has changed. We no longer get the typical misty June weather before the hot, dry summer season. Higher summer temperatures and a dryer climate worsen the situation and forecasters expect these trends to continue. Increasingly warm Seattle summers call for drought-resistant plants and trees. Our ISA certified arborists suggest a few modifications to help your landscape handle complications from extreme heat and prolonged drought in the summer months.
This year our normal summer watering needs become even more critical since our trees have been at a water deficient most of the spring. So, the obvious question is – How much and how often should I water? This depends on the location, tree type and how mature it is – among other factors.
If the leaves are brown on the edges and are drooping or wilted, your tree isn’t getting enough water. Long term water stress usually leads to twig dieback, very little new growth and more susceptibility to insects and diseases.
Another solution to pest management that has become more popular in recent years is the release of beneficial insects. These are essentially good guy insects that attack the eggs or larva of the harmful insects. In the natural, their population in a given area varies a lot depending on the sources of food they have.
Beneficial insects are a valuable asset to the ecosystem, besides preying on harmful pests, they are good pollinators too. An example of a beneficial insect is green lacewing. They have a wide array of insect targets including aphids, psyllids, and Tussock moth and other caterpillars. Beneficial insect releases can be incorporated into plant health care programs, especially as a multi-year plan to combat ongoing pest infestations. Incorporating beneficial insects to your landscape help restore a healthy and natural balance to the environment.
Phytophthora root rot is caused by a soil-borne organism. When first infected, the coast redwood’s foliage may wilt, yellow and dry out but remain on the tree. The leaf damage is because of the slow death of the redwood’s roots, which limit its ability to absorb adequate amounts of water. Eventually, the entire tree will turn brown and is unlikely to recover. If caught early enough, phytophthora root rot’s presence in the soil may be managed, or at least reduced, with the application of a fungicide containing potassium phosphate. But this is not always successful.
One measurement we use in helping to determine overall soil health is soil pH. This is a common concept and important to understand, but is only one of many measurements we use to determine overall soil health. A good soil health recommendation will take many factors into consideration, but soil pH is the starting point, as it helps us determine nutrient availability, the tightness of soils, and the ability of soil biology to thrive or not. The wrong pH may encourage fungal pathogens, while the proper soil pH range will encourage good soil microbes.
The pH scale runs from 0 to 14. Any pH reading below 7 is acidic and any pH above 7 is alkaline. A pH of 7 indicates a neutral soil. Most trees will grow in soils having a pH between 6.5 (slightly acid) and 7.2 (slightly alkaline). Ideally, maintaining a soil close to 6.8 is perfect for most trees. There are a few plants that prefer a soil pH below 6.0. These “acid-loving” plants include azaleas, rhododendrons, and blueberries. The soil pH for these plants can be lowered by incorporating elemental sulfur (S) into the soil. Since the soil acidifying response to elemental sulfur is slow, it should be applied and incorporated a year before planting.