Q. This may be a silly question but when a plant label or gardening book says full sun, does this mean that the plant needs direct sun for the whole day or will it be okay if it gets shade in the late afternoon?
A. No, this is a very legitimate question that’s not asked very often. Full sun is defined as any plant that requires six hours or more of direct, unfiltered sunlight per day. The sun exposure is not a year round measurement but from mid March through October. Another way of thinking of this is when Day Light Saving Times is in effect. It’s also important to realize that the information on plant labels and gardening books are not tailored to your specific neighborhood. Instead, they’re designed for a region that may include several states. The USDA Hardy Map or the Sunset Western Garden Book Climate Zones are the primary resources. Shade in the late afternoon should not be a problem for sun loving plants. A ‘shade loving’ plant is any plant that requires filtered sun with less than three hour of direct sunlight per day. Full shade does not mean no sunlight. There aren’t many plants, except mushrooms, that can survive in the dark.
In addition, there is another, very broad group of plants that are listed for “sun or part shade.” These plants will need some relief from the intense late afternoon sun, either from shade provided by a nearby tree, other plantings, a building or other means. You should keep in mind that the hottest temperature of the day occurs in mid to late afternoon. There are a wide variety of microclimates in Alameda and Contra Costa Counties. Identical plants can tolerate afternoon sun in one location and burn up in another. For example, Azaleas require morning sun and afternoon shade in Livermore but will grow in the full day sun in Alameda. Thus, measuring the sun exposure for plants is not an exact science. This has lead to a plethora of “sun to part shade” labels that seem to dominate gardening books and plant tags. I’m surprised to see Coleus, Japanese Maples, Fibrous Begonias, Impatiens and other so-called “shade loving” plants thriving in the afternoon sun on the hottest days. The nursery professional at your favorite garden center is an excellent resource to help sort things out.
Q. Now that I’ve harvested all the fruit off my apricot, plum and cherry trees, how should I go about watering them this fall?
A. You should scale back the water on fruit trees once Labor Day has passed. A single application in September and October is sufficient. I’d stop watering all established fruit trees in November. The two exceptions are those varieties with maturing fruit and those growing in containers. Citrus is also an exemption. Although they do not show it yet, they’re in the early stages of dormancy and do not require the moisture. You should resume watering next spring after the rainy season has ended.
Buzz Bertolero is Executive Vice President of Navlet’s Garden Centers and a California Certified Nursery Professional. His web address is dirtgardener.com and you can send questions by email at firstname.lastname@example.org or to 360 Civic Drive Ste. ‘D’, Pleasant Hill, Calif. 94523 and on Facebook at Facebook.com/Buzz.Bertolero