By Brett McGhie, Butte County Master Gardener, February 1, 2013
Integrated Pest Management (IPM) is a science-based pest management process which focuses on the long-term prevention of pests and their damage by managing the ecosystem. The University of California Division of Agriculture and Natural Resources has developed an IPM program dedicated to helping Californians “prevent and solve pest problems with the least unintended impacts on people and their environment.” For the home gardener, a guiding principle of IPM is to understand why your landscape favors particular pests, and help you enact changes which will make that environment less attractive to those pests.
The first steps in the IPM process involve identifying what pests are present and then monitoring their numbers and the extent of the damage they are causing. At this point, it can be determined whether the pest can be tolerated, or if further actions need to be taken. The guiding principal with IPM is to use the least harmful control method(s) that will be effective in managing a particular pest. These methods include one or more of the following: cultural controls, biological controls, mechanical and physical controls, and chemical controls.
Cultural control involves creating an environment that prevents and/or reduces pest populations. Practices such as careful site selection, sanitation (removing garden debris), water management and fertilization are examples of cultural control. Many pests overwinter in garden debris left lying on the ground. If plants are stressed because of poor growing conditions, they are more susceptible to insect attack. Fungal diseases can be encouraged if too much water or fertilizer is applied to the garden. Controlling pest damage might also be as simple as selecting plants that are disease- or pest- resistant. In the long run, good cultural practices often eliminate the need for other pest control measures.
Biological control uses natural enemies, such as predators like ladybeetles, lacewings, or praying mantis, to control pests. Natural enemies also include parasites and pathogens (diseases that attack the pest). For example, several tiny wasp species parasitize garden caterpillars, and the pathogen Bacillus thuringiensis, is a commercially-available bacterium that attacks caterpillars, but is nontoxic to other organisms.
Mechanical and physical controls either kill a pest directly or exclude it from an area. A gopher trap is an example of mechanical control. Physical control includes mulching, cultivation, or mowing to eliminate weeds, and the use of nets and screens to exclude insects and birds.
Chemical control is the use of pesticides. With IPM, pesticides are used as a last resort and in combination with the other control methods mentioned above. If pesticides are deemed necessary, it is important to use them as selectively as possible and to take into consideration how safe a pesticide is for other organisms, including the natural enemies of the targeted pest.
The Butte County Master Gardeners, along with Master Gardeners statewide, have been trained in the UC Agriculture and Natural Resources IPM program and are ready to support local gardeners who are interested in utilizing this approach to pest management. If you want to know more about IPM, you can call the Butte County Master Gardeners at (530) 538-7201. You can also read more about IPM by visiting the UC Davis IPM website: www.ipm.ucdavis.edu.
By Ken Hodge, Butte County Master Gardener, February 15, 2013
Growing your own fruit has become very popular, especially in these times of economic downturn. And February and March are an excellent time to plant fruit trees bare-root, which can be a budget-friendly way of starting a home orchard.
It is not difficult to grow fruit trees, but with some help and planning, growing your own fruit can be even more rewarding. Everyone has their favorite fruits to eat, and some fruit lovers may know which varieties they prefer (such as the Bing cherry, the O'Henry peach, the Freckle Face nectarine and the Dapple Dandy pluot), so your own preferences are a good place to start when planning your home orchard.
It's also good idea to look at a ripening chart to see when different fruit varieties ripen. Choosing species and varieties that spread out ripening dates can provide tree-ripened fruit throughout the year. It is possible to have some type of fruit ripe in your little orchard every season of the year, especially if you include winter- and spring-ripening citrus, such as Washington navel oranges and Clementine or Pixie mandarins.
Another consideration in variety selection is flavor and sweetness. White peaches and nectarines tend to be sweeter than yellow-fleshed peaches and nectarines because they have lower acid content. Since even a small fruit orchard is a long-term project, it's important to read a good description of each variety before selecting your fruit trees.
With plums, many people object to the tartness of the fruit, especially in the skin and around the pit. But in Pluots, plumcots and Apriums (a plum x apricot hybrid), the tartness is replaced by more sweetness.
Many varieties of cherries, pears, Asian pears, plums and pluots need to be pollinized by another variety. For instance a Santa Rosa plum is fine by itself, but a Flavor Supreme pluot needs the Santa Rosa plum or another pluot that blooms at the same time, in order to pollinate it and set fruit.
Likewise a Stella cherry is fine by itself, but a Bing cherry requires the Stella or a Black Tartarian cherry for pollination. Pollination is not overly complicated, but it is important to get it right. Fortunately fruit growing is so popular in Butte County that one of your neighbors may have a tree that fulfills your pollination needs, so you might ask your neighbors what kind of fruit trees they have growing already.
The site you select for growing trees can be a designated orchard area or the trees can be spread out throughout your landscape. Many trees such as persimmons also make good shade trees and they have nice fall color. Citrus trees or shrubs are evergreen, so they can be used to create a good barrier, similar to a hedge of Photina or privet, but with the added benefit of edible fruit, fruit trees are a practical landscape ingredient that can serve both aesthetics and food production.
Generally fruit trees need full sun to be the most productive, but even a half day's sunlight may suffice although fruit production will be reduced. If partially shaded trees stretch for sunlight, more pruning may be required to keep the trees bushier.
Growing your own fruit can be very rewarding and you'll be surprised how many friends you have when your fruits are ripe. But seek good advice and check out your options before planting, since even a mini fruit orchard is a long term project that you’ll want to get right from the beginning.
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 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 Cindy Weiner, Butte County Master Gardener, April 12, 2013
Have you ever felt overwhelmed by the selection of plants at the nursery? Or bought a plant that looked great at the nursery, but did poorly (or died) in your yard? Spring is here and it’s tempting to rush out and buy new plants for the garden. But don’t be too hasty! Choosing the right plant for a particular location requires some homework. The time you spend beforehand will pay off by greatly reducing plant "failures."
First, consider the function you want the plant to perform in the garden. Do you want it to provide shade or act as a windbreak or hedge? Will it be a focal point? Would you like colorful flowers? These decisions help narrow your choices at the nursery.
Next, consider the environment of the site. Many factors in your yard affect how a plant grows. Is the soil heavy or does it drain quickly? Is the site in full sun or shaded? Does it get blazing afternoon sun? Is it exposed to reflected heat from a patio or wall? How much water will it get from existing (or planned) irrigation?
When selecting a plant, carefully consider the specifics of the site. Look at the plants growing nearby and think about how you want the new plant to blend in, in terms of size, color and texture. Will the plant be under power lines or by a fence or pool? These elements can affect your plant choice. Tall shrubs or small trees planted under power lines will require frequent pruning. A large plant can grow into your neighbor's space or drop litter into a pool.
After thoroughly analyzing the planting site, think about the characteristics of the desired plant. Do you want a tree, a shrub, a low-growing perennial, or simply annual color? Evergreen or deciduous? What height and width should it be at maturity? You don't want it to outgrow the available space. What water requirements should it have to match the surrounding plants? It's much easier to plan appropriate irrigation to keep plants healthy if plants growing in the same area have the same water needs.
There will still be a large number of possible choices, so you'll need to narrow your selection more. Consider choosing natives or other plants with lower water needs, since they are well adapted to our climate, and many attract beneficial insects. Talk to your neighbors, and look at their garden successes. Call the Master Gardener hotline for advice (530-538-7201.) Visit a nursery to look at their plants, examine the labels, and ask employees for suggestions. The labels have information about eventual plant size and temperature tolerances.
Check to make sure the plant is suitable for our climate. Choose plants appropriate for your USDA Hardiness Zone (these are based on winter minimum temperatures in an area) OR refer to the Sunset Western Garden Book's plant climate zones, which also take other factors, such as heat, humidity, wind, and length of the growing season, into consideration. In Sunset's system, Paradise is in Zone 7, Chico and the valley floor are in Zone 8, and the Oroville foothills are in Zone 9. There are gardening books and online sources with good plant suggestions for these zones. The Sunset Western Garden Book describes 9000 plants that grow in the West and also has lists of appropriate plants for specific situations. The UC Davis Arboretum publishes a list of 100 Arboretum All-Stars, easy-to-grow plants that do well in our valley climate. Arboretum All-Stars can be found at:
Doing your homework to choose the right plant will improve survival and make your plant selections more satisfying.