Do you associate vegetable gardening with the heat of summer, like fireworks on the Fourth of July or the drone of air conditioners on an August afternoon? The amazing thing about California is that we live in a Mediterranean climate zone with hot, dry summers and mild, wet winters, where we can grow food all year.
But wait! It's already September -- isn't it too late? Not at all, because every season of the year in California has a surprising variety of plants that can be grown for food right in your back (or front) yard. Last week's Real Dirt column focused on dirt: specifically, finding some! Once you have located your patch of soil, you're ready to begin a garden. The first step is to dig. This sounds uncomplicated, but there is actually more to it than you might imagine. Your soil has a structure that supports plant life as well as billions of bacteria and millions of microorganisms and fungi, not to mention nematodes and earthworms! Digging disturbs soil structure because it destroys soil aggregates, or tiny clumps, that create pore spaces in the soil used as pathways for water, oxygen and plant roots. The University of California Division of Agriculture and Natural Resources (UC ANR) recommends gardeners dig or turn over garden soil no more than once a season and doing so when the soil is moist but not wet to a depth of about 6 inches. A simple shovel works well. A small rototiller is another option (make sure it won't dig too deep). And you don't need to till or dig up the whole garden plot. One smart option is to dig planting rows about 18 inches wide, leaving walking spaces of 24 to 30 inches undisturbed between them. On the other hand, some gardeners do not dig at all, and instead use a gardening method called “No Till.” If you're not a fan of digging, this method is for you!
To start a No Till garden, first mow or trim any vegetation as close to the ground as possible, then water thoroughly and cover the area with cardboard or thick newspaper, dousing the cardboard or paper with water as well. Next, add a four- to six-inch layer of compost mixed with garden soil or worm castings. Compost can be purchased, but you can also make your own for free (for details see Compost in a Hurry). The cardboard or paper beneath the compost will gradually decompose over a period of six to ten months, along with the roots and closely-cut remains of the weeds, lawn or plants underneath the cardboard.
Once, your garden area is prepared you're ready to plant! Think about the vegetables you and your family enjoy eating. Common cool-season vegetables that are planted in the fall include asparagus, beets, broccoli, Brussels sprouts, chives, cabbage, carrots, cauliflower, Swiss chard, kale, leeks, lettuce, onions, garlic, parsnips, peas, radishes, spinach, and turnips. Consult these Master Gardener planting guides for the valley and foothills of Butte County for information on the best months to plant, when you can expect to harvest your crop, and whether to sow seeds or use bedding plants.
Cool season vegetables grow best in early fall when the soil temperature is between 55 and 75 degrees Fahrenheit in the root zone (four to six inches below the soil surface). All cool season vegetables can tolerate light frost, and some, like broccoli, Brussels sprouts, kale, turnips, onions and garlic, for example, can survive even heavy frost. Keep in mind that once the weather turns wintery and soil temperature drops below about 50 degrees Fahrenheit, most vegetables grow very little or not at all until things warm up again in the spring. By getting your vegetables planted now, they will grow happily through the cool, crisp days of autumn until first frost, or even beyond! With a modest investment in seeds and bedding plants, you can put food on the table for yourself and your family, with the satisfaction of knowing you took that unused patch of dirt and transformed it into productive ground.
The UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area, visit our website. If you have a gardening question or problem, email the Hotline at firstname.lastname@example.org (preferred) or call (530) 538-7201.
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.