By Cindy Weiner, Butte County Master Gardener, January 24, 2014
Most of California has a Mediterranean-type climate with cool, rainy winters followed by hot, dry summers. Many of the plants for sale in nurseries need help to survive in this climate, and often require a lot of water during the summer. However, plants native to California (meaning that they were present prior to the arrival of European explorers and colonists) have adapted to this climate with a variety of strategies that allow them to live with no water for long periods of time. One of these strategies is to bloom and grow during the rainy season and go dormant during the hottest part of the summer.
Manzanitas (scientific name Arctostaphylos) are one group of California natives utilizing this strategy. Their small, urn-shaped flowers, appearing during winter, range from white to pink and are followed by reddish fruits resembling tiny apples. In fact, the word manzanita is Spanish for “little apple.” Manzanita flowers are a good source of food for bees, butterflies and hummingbirds, and many other birds eat the fruit. Manzanitas come in a wide variety of sizes and growth habits, from groundcover to tree-like, but all are evergreen, with leathery leaves and smooth, mahogany-colored bark providing year-round interest. They generally require good drainage, enough space around them to allow for good air circulation, and little to no summer water.
Another reliable manzanita for this area is the cultivar ‘Dr. Hurd.' It grows from ten to fifteen feet tall and as wide and can be pruned as a small tree. The contrast between the dark reddish bark on the spreading branches and the gray-green leaves is quite striking, becoming even more beautiful with age. White flowers bloom in the winter. ‘Dr. Hurd' prefers full sun and little summer water although it can tolerate some irrigation and heavier soil.
Pipevine (scientific name Aristolochia californica) is native to foothills and valleys of northern California. It grows in both lower and upper Bidwell Park, usually near water. Its ten to fifteen-foot-long vines climb into shrubs or trees or along fences without harming them. Blooming in winter or early spring before its heart-shaped leaves appear, the pale green flowers with dark maroon veins are unusual in appearance, resembling curved pipes with flared bowls. It is the only local larval host plant for the pipevine swallowtail butterfly. Pipevine tolerates just about any soil but needs part to full shade and a little water in summer. While it can be grown as a groundcover, pipevine is most effective where the flowers can dangle at eye level to be appreciated.
Planting winter-blooming natives in your garden provides both food for wildlife and lovely flowers to enjoy when most of your garden is dormant.
By Brent McGhie, Butte County Master Gardener, October 4, 2013
As days shorten and temperatures cool, the pace of gardening slows along with plant growth. But there is still plenty to be done during the fall and winter months. In fact, much of what is done in the garden now will set the tone for the following year.
Cleaning up the garden is an important chore. Remove any dead plant material from the garden and add it to your compost pile. Pick up any fallen fruit from around fruit trees. These actions will eliminate habitat for overwintering diseases and pests. Rake up leaves. Matted leaves left on a lawn can suffocate it. Instead, add your leaves (chopping up the largest ones) to your compost pile. If you delay dead-heading your spent flowers and seed heads until early spring the birds will appreciate having this extra source of food during the lean winter months.
Prune deciduous trees and shrubs during their dormant period. However, it is worthwhile to do a little research on each plant to become familiar with its pruning requirements. For example, pruning early-flowering plants such as azaleas, flowering quince, or forsythia in the fall will remove flower buds and reduce the spring flowering display. If these plants require pruning, it should be done just after they have finished blooming.
Consider planting a winter garden. Radish, spinach, pea and onion seeds can be planted in October or November. Cauliflower, broccoli, lettuce and turnip seedlings can be planted in November. If you don’t want a winter garden, clean up your summer garden and mulch it with straw, grass clippings or chopped leaves. Mulch will discourage weeds and provide soil nutrients for next year’s garden.
Planting bare root trees and shrubs during their winter dormancy allows healthy root systems to develop before budding out in the spring. Fall is also the time to plant bulbs and perennials. Squirrels can notice disturbed soil and may dig up tulips and other bulbs. Disguise your work by flooding the soil surface with water and then covering the soil with mulch.
Renovate garden beds by weeding, adding organic matter, and tilling the soil to a depth of at least six inches. Refresh existing mulch around established plantings.
Conduct an irrigation review and adjust your watering schedule to reflect the lower water requirements of fall and winter. Make any repairs (such as fixing broken pipes, hoses, or damaged sprinkler heads) before spring. If you have an automatic system, be sure it is operating correctly.
If you plan to create new garden beds, fall is a good time to do it before you are faced with the rush of spring gardening jobs. And if you plan on creating a new bed in an existing lawn area, a good method is to cover it with a thick layer of newspaper topped with a layer of mulch. This will kill the lawn (as long as it’s not a dormant perennial like Bermuda grass) and the bed will be ready to be worked in early spring without the effort of manually removing the sod.
Finally, clean and sharpen your tools. Keeping tools clean helps prevent the spread of disease and prolongs the life of the tools. If you prune diseased plants, disinfect clippers, loppers or saws with a diluted bleach solution, blot them dry, and then apply a light coating of oil. Sharp tools produce clean cuts and clean cuts heal more quickly. If you have empty flower pots that you are planning to reuse, clean them by removing dirt with a coarse brush and then rinsing with water. Let terra-cotta pots dry completely before storing them.
By Jeanette Alosi, Butte County Master Gardener. March 15, 2013
Scales are insects that suck plant fluids by inserting a tiny straw-like mouthpart into various parts of a plant. Scales are very small, and when they are doing their damage (in the larval stage) they are wingless and have no distinguishable body parts. Unlike aphids, for example, scales are slow moving or immobile.
The damage of a scale infestation depends upon the type of scale, the species of plant, environmental factors, and the proximity and numbers of natural enemies.
The two common scale families are soft and armored scales. Soft scales may be smooth, cottony, or waxy. They are usually about one-eighth to one-quarter-inch in diameter, and round to oval in shape. They feed on fluid-conducting phloem plant tissue and excrete honeydew. Common soft scales are black scale, brown soft scale, cottony cushion scale, and European fruit lecanium scale.
Armored scales are tinier than soft scales (less than one-eighth-inch) with a flattened, removable scale cover. They do not excrete honeydew. Common armored scales include California red scale (on citrus) and San Jose scale.
There are many other species of scales and scale look-alikes. It is important to identify the scale family in order to determine the most effective control methods.
Most female scales produce eggs without mating. The eggs hatch into crawlers (also known as first instar nymphs). Crawlers, about the size of a typed period, are usually pale yellow to orange. After a few days, they establish themselves on a nearby feeding site and rarely move again. Once they become firmly attached to a feeding site, scales will grow through several larval stages during their lifetime (although their appearance will not radically change) before becoming adults. Most soft scales produce one generation a year. Armored scales produce several generations a year.
Scale damage is dependent upon the level of infestation. In addition to yellowing leaves, plants affected by scales may experience premature leaf drop and discolored blemishes on fruit, leaves or twigs. If heavily infested with armored scales, twig dieback may also occur. The main problem with soft scales is the secretion of sugary honeydew which attracts ants and encourages the growth of black sooty mold. Soft scales rarely kill trees and shrubs but can reduce plant vigor, while recurrent infestations of armored scales can cause twig and branch dieback.
In most cases, scales are controlled by natural enemies, especially parasitic wasps. A parasitized scale will appear darker than normal. Other natural enemies include lady beetles (“lady bugs”), lacewings and mites. Because ants feed on the honeydew secreted by scales, they will protect the scales from their natural enemies. Controlling ants will therefore help to decrease the scale population. Beware of using broad-based insecticides because they kill beneficial insects and scale parasites indiscriminately, as well as the scales and ants.
Cultural practices to control scales include pruning to improve air movement and light penetration into dense canopies, and selection of plants that are less prone to scale infestation. Because scales tend to be host-specific, replace problem plants with plants less attractive to scales. Planting flowering plants near scale infestations will aid in attracting natural enemies.
For limited scale infestations, prune out heavily infested branches. Pruning to open up the tree canopy will expose scales to the hot sun, increasing their mortality.
Heavy infestations may require the use of horticultural oil during the dormant season or when the crawlers (nymphs) are active during the growing season (late winter to early summer). Read the label carefully when mixing with water, as horticultural oils may damage plants under certain conditions. To smother (and destroy) the scales, affected areas including the undersides of leaves must be thoroughly coated with the horticultural oil spray. On larger ornamental shade trees (non-fruit-bearing), a soil-applied systemic insecticide might be considered.
For more information, see “Scales, Pest Notes Publication 7408,” at
Photo: San Jose scale on peach branch/span>
By David Walther, Butte County Master Gardener, March 1, 2013
Early spring is the perfect time to apply mulch to your garden. Mulch is any material that covers the ground and insulates it from sun, evaporation, and erosion. After you have finished your winter cleanup and pruning chores, but before the rains end is a great time to mulch, not only to provide the best environment for your plants, but also to help prevent the growth and development of weeds.
Mulch is good for the soil, and thus good for your plants for a number of reasons. It jump-starts the useful work done by microscopic organisms (this is often referred to as microbial activity); retains moisture, thus preventing plants’ roots from drying out; and deters weeds by providing a barrier between the soil and the sun.
Mulching is also a time-saver for the gardener – it takes a fraction of the time to put down mulch that it would take to weed later on. And using mulch to control weeds reduces the use of expensive herbicides.
Mulch can be composed of organic or inorganic materials. Organic mulches include manure, compost, grass clippings, shredded bark, shredded wood, and even newspaper sheets (more attractive when covered with compost so the newspaper doesn’t show). Pine needles can be used as mulch but they are very flammable, so it is best to chop or grind them up first. Shredded leaves from fall leaf drop make excellent mulch.
Natural inorganic mulches include gravel, pebbles, and crushed stone. Other inorganic mulches are plastic, cardboard, and even pieces of old carpet. The mulch you use will depend upon the job you want the mulch to perform and how you want it to look.
Any ground that needs enrichment, such as flower or vegetable beds you will be planting later in the season, will benefit from an application of organic mulch. Mulching around shrubs, trees, annuals, and perennials will improve the soil that feeds their roots, as well as deter weeds. Large areas that you wish to keep weed-free are also candidates for a thick application of mulch.
Pile mulch six to eight inches deep, tapering down to three inches deep about 10 inches away from the stems or crowns of plants. Do not place mulch directly on top of plant crowns or too close to the trunk or stems of your plants, since a layer of mulch can cause the crown to rot. You can, however, apply mulch right on top of plants that do not have above-ground stems or crowns (such as bulbs, stoloniferous or rhizomatous plants).
To control annual weeds, apply four to six inches of mulch on top of the soil, or even on top of the weeds themselves. To control perennial weeds, an application of 12 to 16 inches of mulch is needed.
The reappearance of weeds in an area that has been mulched is an indication that the mulch has decomposed to such a degree that a new application of mulch is required.
While the benefits of applying mulch are many, mulch can also lead to an increase in mole activity because of the increase in the worms and grubs they feed on – the more alive your soil is, the more it becomes a habitat for other creatures.
Mulch can deplete the soil of nitrogen during the process of decomposition, so it is a good idea to supplement occasionally with applications of fertilizers rich in nitrogen such as manure, bloodmeal, feather meal (made from chicken feathers), or cottonseed meal.
Finally, different garden situations require different choices of mulching materials: for example, dryland garden plants (xeriscape plants) such as native California plants, cacti, and succulents, have evolved to flourish in dry conditions and poor soil. The moisture-retentive qualities of organic mulch could be detrimental to their vigor and growth while the use of stone or gravel mulch would be helpful in replicating their natural environment.
Your mulch choices can range from commercial mulches purchased at a landscape center, to bags of organic mulch available at nurseries and home improvement stores, to your own (free!) shredded leaves, grass clippings, and yesterday’s paper. The benefits of mulching far outweigh any negatives, so there is no reason not to mulch.
By Tom Hansen and Jeanne Lawrence, Butte County Master Gardeners, January 4, 2013
Honey bees will be brought to Northern California from all across the US to begin pollinating the almond crop by mid-February. Although almonds don’t have a lot of nectar, they do have a lot of pollen, which allows the bees to build up the strength of their colonies after the arduous journey of travelling across the country.
Honey bees can forage as far away as three to five miles from their colony when conditions are favorable for flight, although most foragers tend to stay within a few hundred yards of the colony if it is near adequate food rewards (nectar and pollen). Honey bees will venture out from their hives when temperatures reach the mid-50s Fahrenheit; they won’t travel far, but they will search for sources of pollen and nectar nearby.
Because honey bee queens are constantly laying eggs and raising their young, these bees need food year-round. Honey bees forage when temperatures are 55 degrees and higher; they do not forage in rain or in wind stronger than 12 miles per hour. Cloudiness also reduces flight activity, especially near threshold temperatures. A honey bee normally flies at a speed of 18 miles per hour empty and 15 miles per hour carrying of load of pollen or nectar. However, if they are agitated and empty, honey bees can fly about 20 miles per hour. They cannot carry a load upwind against much more than a 15 mile-per-hour wind.
Native bees, like bumble bees and mason bees, are solitary and do not live together in hives like honeybees do. Solitary native bees were here long before the arrival of honey bees, which were introduced from Europe in the early 17th century. Native bees lay their eggs throughout the summer and fall and their pupae (young) develop in seclusion during the colder months. They need daytime temperatures of 65 to 70 degrees before they emerge as adults, so they will not begin pollinating until early April, or when daytime temperatures rise. While native bees do not play a significant role in almond pollination, they are critical in pollinating many of our summer fruits, vegetables and flowers.
Different species of pollinators are attracted to different types of flowers (generally those that suit their tongue length), but nearly all types of bees show interest in blue, yellow and ultraviolet hues.
Some guidelines for bee-friendly garden plantings include the following:
- Natural species (rather than hybrids) produce nectar and pollen that is more accessible for bees
- Native flowers can attract solitary bees (like mason bees)
- Grow a variety of species from different plant families
- Try to have something flowering throughout the season
- Plant several of one type of plant together – they will provide a better magnet for the bees
You can help bees out by planting mustards or clover as a cover crop – yellow mustard is one of the earliest blooming flowers that are attractive to honey bees. Native plants and shrubs that are attractive to bees include the California wildflower “Baby Blue Eyes,” and California Desert Bluebells, both of which are annuals; and California Dutchman’s Pipe, an attractive deciduous vine festooned with cream-colored flowers that have red-purple veins.
Non-native plants that are bee-friendly in our area include flowering quince, which is often the first noticeable flowering shrub of the year; the popular evergreen camellia japonica, some varieties of which bloom as early as November; and witch hazel (hamamelis), a yellow-flowering shrub with a distinctive fragrance and intriguing blossoms.
Crocus and hyacinth bulbs are also attractive to bees. These should be planted in November or December after spending 10 weeks chilling in a refrigerator ahead of time (as our climate is too mild to provide them the requisite chill hours) – and, like tulips, these are best treated as annuals in our climate.
When doing your winter garden clean-up, keep the bees in mind: leave some “wild,” messy areas in your yard for bees. For example, old fence posts, dead logs, and decaying sunflower heads all provide native bees with places to hide, nest, and raise their next generation.
Keep other pollinators in mind, too: for instance, instead of using a hummingbird feeder which you might only sporadically keep filled, provide natural nectar at this time of year by planting camellias, flowering quince and flowering currant.
Photo: Honeybee on prune blossom/span>