Summer Pruning of Apple Trees

Posted on August 3, 2014 by tomkarwin

Do you have one or more apple trees that have vigorous new upright growth, like the shoots, often called water sprouts, shown in the picture? This photo shows new growth on an espaliered Gala apple in my garden, before and after pruning (click to enlarge).

BEFORE PRUNING

AFTER PRUNING

Those shoots, usually at least one foot in length, are the tree’s response to heavy pruning during the dormant season, and represent an effort to restore the balance between the canopy and the root system.

Water sprouts are unlikely ever to bear fruit. Instead, they sap the tree’s energy and shade the interior of the tree, slowing the development of vertical growth, and the time for dealing that problem begins now. The period from early August to mid-September is the ideal time for summer pruning, after the new branches have set their terminal buds. This means that the branch has stopped growing for the season, so pruning will not stimulate additional growth. The best practice is to remove the water sprouts with their terminal buds.

Note that some new shoots will be shorter, and horizontal or nearly horizontal. Horizontal shoots (properly called “laterals”) are more likely eventually to bear fruit, so they are treated differently from the vertical or near-vertical shoots.

First, consider training these laterals to close to horizontal, using string or V=notched spreaders, to support fruiting.

Then the recommended treatment is to prune these laterals back to three buds of new growth after the cluster of leaves at its base. This will stimulate the formation of fruiting buds.

Oren Martin, the gardening guru at UC Santa Cruz’s Farm & Garden, says this three-bud pruning system is based on the advice of Louise Lorette a French orchardist of the early 20^th century.

Pruning your apple tree’s water sprouts and laterals in this manner can be a repetitious and fussy detailed task, but it really will not take long and will contribute significantly to your tree’s vigor and productivity.

My practice is to listen to National Public Radio on a portable radio while pursuing repetitious tasks like pruning or weeding. That way I can feel like both a conscientious gardener and an informed citizen.

Summer pruning of apple trees is distinctly different from winter pruning, which should focus on the tree’s structure and overall form. Summer pruning, by contrast, emphasizes the tree’s details, keeps sunlight flowing to the interior and supports fruit production

The time for structural pruning of an apple tree is late winter while the tree is dormant and leafless. Winter pruning can stimulate the growth of water sprouts, which are pruned in summer when the tree is not producing new growth. This practice results in less pruning down the line.

When the dormant season comes again, we’ll review the art of winter pruning. Now, during the summer months, pick up your clippers and snip away at those water sprouts.

Gardens as Tools

Posted on June 27, 2014 by tomkarwin

Following recent surgery, I felt too fatigued and sore for even light gardening. Those limitations lasted about one week, after which I could again put in several hours on easy—and overdue— tasks: weeding, installing small plants, pruning, all of which helped a lot in my recovery.

This episode stimulated thoughts of the garden’s many functions beyond pleasing the eye, feeding the stomach and providing regular light exercise.

Without minimizing the direct benefits of ornamental and edible gardening, consider the types of therapeutic gardens: healing, meditation, contemplation, and restorative.

“Healing” means helping individuals to overcome physical, mental, emotional or spiritual challenges.

“Meditation” involves deepening personal knowledge and attaining inner peace.

“Contemplation” involves thoughtfully examining issues larger than oneself, perhaps in a religious or mystical manner.

“Restoration” refers to returning to an ideal or normal state from a stressed or agitated state, or from boredom or difficulty in focusing.

A garden designed to help individuals to overcome physical challenges is described as an accessible garden. The design typically emphasizes raised beds, tall enough to provide easy access to the gardener who cannot kneel, or finds it difficult to do so. (Rising from kneeling could be just as challenging.) There are also convenient tools, e.g., rolling seats, tools with long handles, telescoping pruners, for gardeners who have grown to be less than spry.

Other kinds of accessible gardens are designed for gardeners with partial or complete loss of sight, emphasizing blossom fragrance or plant texture over appearance, to favor smell or touch.

No garden, however accessible or well intentioned actually effects any healing or restoration. Only the gardener who desires to be healed or restored can achieve such outcomes. In this perspective, the garden is not the cure, only the gardener’s tool.

The focus on the gardener is the same for meditation and contemplation gardens, which offer only nature’s calm environment to invite the gardener to forget for the moment personal stresses and the busy world’s demands, and to consider issues greater than “why snails?”

There’s one more type of therapeutic garden: the motivational garden, which helps those who may be bored or having difficulty in focusing. Once we have begun gardening, and experienced the satisfaction of seeing plants grow under our hands, even a brief visit to the garden stimulates the urge to pull a weed, deadhead a faded blossom, or move a misplaced specimen to a better spot.

Gardens are valuable tools for many special purposes; many gardeners find them therapeutic on all occasions.

The American Horticultural Therapy Association provides its definitions and positions regarding therapeutic gardening.

The American Society of Landscape Architects offers an interesting essay, “The Therapeutic Garden— A Definition.”

Pinterest (which collects photos on various topics from many sources has several unorganized groups on topics related to therapeutic gardens. A search on “horticultural therapy ideas” yields this collection, which demonstrates the wide range of ideas that people associate with “horticultural therapy.”

Plants for Rock Gardens

Posted on June 20, 2014 by tomkarwin

Many different plants could be included in a rock garden. The usual design approach limits plant selection to low-growing varieties, but this is not a necessary constraint.

A brief study of the vegetation on a naturally occurring rocky landscape would help in designing a realistic rock garden for a residential landscape.

Some travel could be required to locate one or more good examples; this could be a pleasant weekend excursion with a clear purpose, especially if one knows where to find rocky landscapes. Ask around!

Once found, rocky landscapes might include one or more trees of various sizes, as well as shrubs and smaller plants. Clearly, proximity to rocks does not limit the size of plants.

A late July scene in the rock garden of the University of British Columbia Botanical Garden; photo by Todd Boland.

The assumption that rock garden plants should be low-growing specimens probably relates to alpine gardens, which have inspired many rock gardens. Alpine gardens feature plants that grow naturally in high-altitude, mountainous areas, which typically have large stones and much gravel, low temperatures, low moisture, and poor soil nutrition. Plants that survive under such conditions might very well be small in overall size and low growing.

Developing an authentic alpine garden, however, involves reproducing the challenging conditions in which alpine plants are found. There are alpine varieties of some familiar garden varieties, e.g., Campanula, Dianthus, Geranium, Phlox, Primula, Ranunculus, Sedum, Sisyrinchium, Thyme. If such plants were to be grown in a moderate climate, in rich soil and with ample moisture, they would respond with more lush growth and greater size than they would in a true alpine garden.

Rock gardens should not be confused with alpine gardens. In fact, rocky landscapes can and do occur in a wide range of climates, with the only common characteristic being exposed rocks. So, in planting a rock garden, the gardener should first select plants that will thrive in the local environment. The Monterey Bay area’s climate supports a wide range of choices.

The rock garden designer still might want to emphasize low growing plants to keep the vegetation in scale with the surrounding landscape and the rock garden itself, and to keep the rocks visible (they might have required a significant investment).

Another consideration is the relationship of the plants to each other. This perspective might lead to developing a plant community, i.e., a grouping of plants that grow together in nature. Other possibilities include a thematic approach, e.g., a white garden or an analogous or complementary color scheme. In our moderate local climate, the designer also might plan for year-round seasonal color, or for interesting contrasts of foliage or structure.

There are many possibilities, but the most successful and satisfying landscape plans always are based on a plan of some description, rather than a series of impulsive decisions.

Alpine Garden Society – Plants –This is a thoroughly amazing website, a vast treasure trove of images and information about alpine plants. At the site, click on “AGS Encyclopedia” then on either “Families,” “Genera,” Species,” or “Authors” for encyclopedic information. (I found “Genera” most useful.)

The image above came from Images/Photographic Competition/Previous Winners/AGS Photographic Competition, 2012 – Winners

The website invites—and requires—exploration to discover its many riches.

North American Rock Garden Society – Another good source of plant images and descriptions. Not as extensive as the Alpine Garden Society’s website, but helpful as an introduction to rock garden plants. At the site, click on “Plants” for the entry to lists and images.

Rock Gardens & Ground Covers A page of unorganized photos submitted to Pinterest. Interesting to scroll through, to see some very good plant pictures, some attractive designs (more or less naturalistic) and some truly bad designs (but that’s one person’s opinion).

Scottish Rock Garden Club – This website provides free access to many back issues of The International Rock Gardener, an excellent publication.

Rock Gardening

Posted on June 18, 2014 by tomkarwin

Garden renovation projects might include mounds to add visual interest in an otherwise flat terrain, and also to provide drainage and other benefits of raised beds. A particular form of the garden mound is the rock garden, based on a natural or simulated outcrop of rocks.

An outcrop could occur in a flat area, but are most common—and look most realistic when created—on a slope, where erosion over time would have exposed the underling rock formation. If your property includes an area that has a slope of ten degrees or more, and full exposure to the sun, you have a good site for a rock garden. Never mind if it lacks rocks: they can be trucked in from a stone yard.

Lacking a sloped area, the gardener could develop a rock garden on a mound, and should not be reluctant to do so, but should avoid the look of “a dog’s grave,” which results when an isolated bump is placed in a lawn. A mounded rock garden will have a naturalistic appearance when is has substantial size appropriate to the setting, and a backdrop of shrubs, trees, wall or hills.

Another contributor to a natural look is a scree boundary. The base of a natural rock outcrop often will have a loose accumulation of smaller stones and rock chips, called “scree.” So, where sufficient space is available, include a scree bed about two feet wide between the rock garden and the adjacent lawn or pathway. The scree bed should have a foundation of about eight inches of scree compost (1 part topsoil, 1 part compost, 3 parts gravel). An edging would help to contain the stones.

Acquiring and placing rocks will be the most expensive, strenuous and aesthetically challenging part of the project. Here are recommended guidelines:

Use one kind of stone, preferably one that occurs naturally in the area. Traditionally, rock gardens use limestone or sandstone, but in the Monterey Bay area Sonoma fieldstone, an igneous rock (basalt or rhyolite), is widely available and popular.
Commit to the project. Include boulders (stones too large for one person to move) even though they can be difficult to place in desired positions.
Contract with the stone yard deliver materials to as close as possible to their eventual location.
Position stones for a natural appearance: larger stones will be uphill of smaller stones; some stones might be close to other stones.
Bury stones one-third to one-half of their vertical dimension. Stones rarely are found atop the soil.

A rock garden is just one use of stones in garden design. Stones are also used for walls, borders of beds, walkways or patios. All such uses can be attractive in the garden, partly because of the contrast between the surfaces of stones and plants. Recognize, however, the differences between naturalistic rock gardens and these other uses, in which stones are used as building materials.

20 Fabulous Rock Garden Design Ideas —from Decoist.com. These images show fine designs that demonstrate a variety of uses of rocks in the landscape. Not all designs could be called naturalistic.

Rock Garden Ideas — 112 images of rock gardens, ranging from naturalistic designs to “whimsical” ideas. Test yourself on whether these designs follow or violate the five design guidelines listed in this article.

Alpine Garden Society – This society is based in the British Isles, where rock gardens first became popular. Gardeners in the United States have developed many rock gardens, but not with the enthusiastic commitment evident in England.

The Rock Garden – Very good how-to article by Alan Grainger, with sufficient information to guide a novice project. Visit the website, The Alpine Garden for many related garden and plant photos, book reviews and other resources.

Betty Ford Alpine Gardens A large and varied place, designed for visits (not so much for web browsing). This could be the most highly developed public rock garden in the United States.

How to Build Rock Gardens From About.com – This website illustrates a “rockery,” a garden design that is based on rocks, but which does not pretend to a natural look. This might also be called a “dog’s grave.”

A New Food Labeling Faceoff

Posted on April 5, 2014 by tomkarwin

The California Senate Health Committee recently approved Senate Bill 1381, which would require the labeling of genetically engineered (GE) foods. This action is triggering new flows of facts and opinions by interest groups.

This bill renews the long-running debate between consumer groups and pesticide corporations and large-scale food producers. Californians for GE Food Labeling, representing many consumer groups, claims that grocery shoppers need to know what they are buying. The Grocery Manufacturers Association, representing the food industry, claims that labeling GE foods would be expensive and misleading.

This debate dates from 1992, when the U.S. Food and Drug Administration (FDA) ruled that GE foods were “substantially equivalent” to conventionally grown foods and therefore do not require labeling.

Ten years later, Congress created the National Organic Program (NOP) under the U.S. Department of Agriculture. The NOP ruled that GE foods do not meet NOP standards and could not be labeled as “organic.”

According to SB 1381, more than 90% of members of the public want labeling of GE foods. Maine and Connecticut have passed limited laws requiring GE food labeling, and 20 other states are considering similar laws. Voters in California and Washington have considered GE food labeling measures, but the food industry waged massive campaigns opposing the measures and both failed by very small margins.

Sixty-four countries already have laws mandating labeling of GE foods.

Two other Senate committees—Agriculture and Judiciary—will debate SB 1381before the full Senate votes on it. While the bill moves through the California Senate, the California Assembly could consider a similar bill. Both bodies would have to agree on some version of this legislation before it could become law in California. This process could be lengthy, with vigorous arguments for and against.

At the federal level, a year ago, Senator Barbara Boxer and many co-signers introduced The Genetically Engineered Food Right-to-Know Act, but it hasn’t advanced at all.

The FDA has proposed regulatory guidelines for voluntary labeling of GE foods. Consumer groups have dismissed this approach as not helpful.

The Grocery Manufacturers Association recently recommended federal legislation that would allow voluntary labeling of GE foods, allow describing them as “natural,” and preempt state laws that have different requirements.

Meanwhile, grocery shoppers could either buy only certified organic foods, or simply ignore the issue. Home gardeners could buy seeds from “Safe Seed Pledge” companies (listed by The Council for Responsible Genetics) and grow their own non-GE foods.

Food policies have become complicated!

More to come.

Some Garden Thugs You Want Around

Posted on March 15, 2014 by tomkarwin

A weed is simply a plant growing in the wrong place, while a garden thug is a plant spreading without apparent limit, and overwhelming other plants it encounters. Garden thugs could well be landscape assets, given freedom to expand. Here are three examples from my South African succulent bed.

Thug #1: Aloe maculata (Soap Aloe)

Some 550 recognized species are included in the genus Aloe. One of them, the Soap Aloe (its sap makes a soapy lather in water) is among the most popular Aloe species in California gardens. The plant forms a rosette about a foot wide, made of pointed fleshy leaves about eight inches long. In the spring it sends up a two-foot long stalk topped by orange-red flowers in a flat-topped cluster called a raceme. So far, so good, but it also sends underground suckers that soon create a dense colony. I lifted ten plants for this month’s garden exchange, then put another eight in the green waste.

Related species in my garden include A. arborescens (Torch Aloe), also a vigorous grower; A. plicatilis (Fan Aloe), a slow-growing small tree; and A. ‘Christmas Carol’ (hybrid), a smaller plant with vibrant red colors in the leaves. In this group, Soap Aloe is the real thug.

Thug #2: Senecio mandraliscae (Blue Finger)

Senecio mandraliscae

Senecio is one of the largest genera of flowering plants, with about 1,250 species that present many amazing forms. Blue Finger, which might be a hybrid, grows twelve-to-eighteen inches tall, with numerous four-inch long blue-gray leaves shaped like fat bean pods. It produces uninteresting white flowers in summer but the foliage is the main attraction. The leaves will drop easily from the plant, and root to form new plants. The spreading stems also quickly establish roots.

A nice-looking succulent plant and a welcome addition to the garden, but one that needs regular whacking to keep it within bounds. My other Senecios are S. rowleyanus (String-of-Pearls) (showing the variability of this genus) and S. haworthii (Wooly Senecio). There could be other thugs in this large genus, but Blue Finger certainly qualifies.

Thug #3: Cotyledon orbiculata (Pig’s Ear, Paddle Plant)

This striking succulent has gray-green fleshy leaves with red margins, and coral red, bell-shaped flowers on stalks in early spring. The leaves grow on stout branches growing any way other than straight. This attractive plant spreads over time, and is considered invasive in some parts of the world. The plant has medicinal uses, but its leaves are said to be toxic to livestock, poultry and dogs. It works well in containers, which might well be the best place for this plant.

These vigorous plants will prove you have a green thumb, but they require control.

Garden Priorities for March

Posted on March 1, 2014 by tomkarwin

Despite our current, most welcome rains, we remain below the normal precipitation level for this time of the year and water conservation in the landscape continues to be important.

Conserving Water

For long-term conservation, plant California native plants or other drought-tolerant plants from the world’s Mediterranean climates. Succulent plants are increasingly popular for this reason, and for their varied forms, textures and colors, and low maintenance needs. (Desert conditions are not ideal for succulents: all need some water and quick drainage, and many enjoy partial shade.)

Shorter-term water conservation strategies include composting and mulching to retain water, using drip irrigation for efficiency, selecting vegetable varieties for low water requirements, eliminating seasonal weeds to reduce competition for scarce water, and irrigating only when plants need water. See “More” (below) for water conservation tips from Master Gardeners.

Fertilizing

Garden priorities for March include fertilizing trees, shrubs and perennials when they begin to show new growth.

For roses, give each plant two cups of a balanced fertilizer, i.e., 10-10-10 or 12-12-12, plus a quarter-cup of Epsom salts, two cups of alfalfa, and a half-cup of rock phosphate or bone meal.

There are differing views for fertilizing some plants. With bearded irises, for example, some growers recommend just a generous handful of a balanced fertilizer for each plant; others advocate low-nitrogen fertilizer, e.g., 6-10-10, plus bone meal and superphosphate. (The thinking is that adding more nitrogen could encourage root problems.)

Pruning

March is a good time for pruning still-dormant trees and shrubs, following recommendations for each plant. Here are examples from my garden:

Thin a large Wild Mock-orange (Philadelphus lewisii) by cutting about one-third of the larger branches to the base of the plant.

Shape a large Milkflower Cotoneaster (C. lacteus) by removing old, unproductive limbs and spindly branches, and generally lifting the canopy to provide more sunlight to the understory.

Renew Salvias by cutting old growth to the ground when the plants begin to show early spring growth. Another shrub that responds well to this treatment is the Tree Daisy (Montanoa grandiflora), from Mexico, which can grow up to ten feet high in one season. This annual treatment might seem drastic but the plants otherwise will become scraggly.

A good book on pruning is The American Horticultural Society’s huge “A-Z Encyclopedia of Garden Plants” (Revised edition, 2004), which briefly describes thirteen pruning categories and indicates which to use for each of 15,000 plants.

More

A thorough presentation on conserving water in the garden: “Guidelines for Managing Drought in the Urban Landscape,” was developed by Sonoma County Master Gardeners Susan Foley, Phyllis Turrill and Jerilynn Jenderseck, with input from Mimi Enright, Sonoma County Master Gardener Program Coordinator and Paul Vossen, UCCE Sonoma/ Marin Farm Advisor. (February 2014)

The following paragraphs, also from the Sonoma County Master Gardeners, provide brief recommendations for water conservation in the garden.

1. Compost, compost, compost! Add organic matter to the soil. If soil is sandy, the addition of organic matter allows the soil to hold more water. Organic matter also helps open up soil allowing roots to go deeper and find more water at lower depths if there is any. Higher soil nutrition helps plants produce better yields with the same amount of water. Avoid adding excessive amounts of nitrogen as this encourages lush leafy growth that requires more water to sustain.

2. Mulch, mulch, mulch! Mulch keeps soil cool, conserves moisture and reduces weeds. Use three to four inches on top of the soil. The larger the material size, the deeper layer you need to provide. Choose from straw, fallen leaves, hulls, shredded bark, grass clippings and newspaper. It is not advisable to use plastic sheeting as mulch because it deprives the soil of much-needed oxygen. Keep mulch two inches away from the base of the plant to avoid the possibility of rot. When hand watering, pull back mulch so that water goes directly into the soil.

3. Use a drip system. Learn about individual plant moisture needs and group plants that have the same need together on the same valve. If using in-line emitters in one-fourth inch tubing that use one-half gallon per hour per emitter and there is a length of ten feet with emitters spaced every foot, five gallons of water an hour is used on that section of tubing. Add up all drip lines to determine total water used. Install a timer. Install shut-off valves at the beginning of drip lines in order to turn them off when an area is fallow. Irrigate only as long as it takes to moisten the active root zone. Water, preferably, in the morning or in the cool hours of the evening so that soil stays evenly moist. Don’t forget the drip system once it is set up. Monitor and adjust it, as needed.

4. Be selective. Consider the water available to support crops through harvest, and grow only the amount and types of vegetables the family will consume. For example, plant two beds of vegetables instead of six; plant four tomatoes instead of ten. To get the most out of the water you apply, grow high yielding vegetables like beans, chard, mustard, eggplants, peppers, tomatoes, squash, quinoa and amaranth.

Do not grow crops that need consistent moisture. Examples include most brassicas (broccoli, cabbage, Brussels sprouts, kohlrabi, cauliflower and radishes), lettuce and other greens, beets, carrots and other root crops, celeriac, celery, leeks and onions. Avoid these unless a particular variety has been bred to need less water. Generally, cool season crops are not drought resistant and growing them during the heat of the summer requires lots of extra water to keep them cool.

Consider the following observations on which crops need the most water and when:

Some beans and sweet corn need considerable water to produce a good crop. Beans need water most when they are blooming and setting fruit.
Corn needs water most during tasseling, silking and ear development. Yield is directly related to quantities of water, nitrogen and spacing.
Peas need water most during pod filling.
Other vegetables, such as cucumbers and squash, and fruits, such as melons, need water most during flowering and fruiting.
Tomatoes, peppers and eggplant need water most during flowering and fruiting. (Note that after tomatoes set, they can do very well with reduced water).

After deciding what to grow, choose varieties that tolerate dry conditions. Look for the terms “drought-resistant” or “drought-tolerant” in seed catalogs or on plant labels (note that “heat-tolerant” refers to above ground air temperature and is not the same as drought-resistant or drought-tolerant). Even these varieties require water. Some water is needed to start seeds or establish a seedling, and to periodically irrigate the plant through the growing season. Selecting varieties that are described as “widely-adapted” in addition to drought-resistant and drought-tolerant also may be helpful.

5. Consider days to maturity. A crop needing fewer days to mature requires fewer irrigations before harvest (e.g., 62-day ‘Stupice’ vs. 85-day ‘Cherokee Purple’ tomato). Look for early-maturing or short-season varieties. Days to maturity will vary from one part of the country to another as well as from one microclimate to another.

6. Increase plant spacing. Spaced plants are not competing as much for water in the soil. Very deep, open soil or French intensive double dug beds allow vegetables to be planted closer together because the roots have more room to grow deeper and find water if it is present. Try increasing the spacing recommended in the SCMG “Vegetable Planting Summary,”iv by 50 percent or even doubling the spacing if you have room.

7. Eliminate weeds. Weeds compete for water. Be aggressive in removing them from growing areas.

8. Use light-weight row covers. Cover plants as a means to collect dew. Dew drops onto soil and keeps it moist. While using row covers can help prevent insect damage, look under the cover from time to time to monitor plant growth and check for unwanted insects trapped inside.

9. Use shade. Heat-sensitive vegetables can benefit from being planted where they receive some afternoon shade. Plant them underneath or behind taller plants or consider using shade cloth.

10. Use windbreaks. The moisture on leaf surfaces is dried by moving air, causing the plant to need more water. In coastal and other windy areas, windbreaks will help roots keep up with leaf demands.

11. Determine when it is time to water again. Use a soil moisture meter. Or squeeze the soil in your hand: if it sticks together, it is still moist; if it is crumbly and falls apart, it is time to water.

California Native Roses

Posted on October 26, 2013 by tomkarwin

Rosa Californica is the only rose in my garden that is native to California. It’s a fine plant, but tends to expand its territory through underground suckers.

When I came upon a healthy specimen of another rose identified as a California native, I grabbed it for my garden and worked to learn more about it and other California native roses.

I soon discovered that my new rose, R. multiflora, is an imposter! It is a native to Japan that has become naturalized in California and much of the U.S. In eastern North America, it is considered an invasive species, and even a “noxious weed” in grazing areas. Although it has many blossoms, it is most appreciated by goats.

Roses that are truly native to California typically have single pink flowers, varying degrees of fragrance, and spiny branches. They often are found near water sources. While they tolerate some drought and shade they grow best with ample moisture and sunlight. They can spread vigorously in hospitable circumstances, but are controllable with seasonal pruning.

Here are several species, in roughly north-to-south order.

California Rose (R. Californica). Grows in much of California in chaparral, riparian and central oak woodland plant communities. Most widely grown native rose. This photo is from the website of the University of California, Santa Cruz Natural Reserves.
As a side note, the UCSC Natural Reserves program includes five sites, including one in Marina and one in Big Creek (south of Carmel). The five sites ring the Monterey Bay along the National Marine Sanctuary that extends the entire coastline from the Golden Gate at San Francisco south to Big Sur, between 38 and 36 degrees North latitude along roughly 122 degrees West longitude.The wide range of habitats, from fog-enshrouded redwood forest to maritime chaparral, provide an unparalleled natural laboratory for marine and terrestrial research and serve as study sites for University scientists and students.
Ground Rose (R. spithamea). Native to central California from the San Luis Obispo area up into Mendocino and Humbolt and in the Sierras from Tulare to Yuba. Grows in chaparral and coastal sage scrub plant communities.
Nootka Rose (R. nutkana). Grows in riparian areas in northern California and up to Alaska.
Wood Rose (R. gymnocarpa). Grows from San Luis Obispo to northern California, and in other western states, and has large fragrant blossoms.
Whiskey Rose (R. pinetorum). A relatively rare rose that has been spotted in northern California and in the Monterey area. Resembles R. gymnocarpa.
Cluster Rose (R. pisocarpa). A fairly large plant, up to six feet high, with flowers in clusters near the top. Grows in northern California to British Columbia.
Mountain Rose (R. woodsii ultramontane). Grows in high elevations east of the Sierras, and produces large numbers of very fragrant dark pink blossoms.
Mojave Rose (R. woodsii glabrata). Grows near springs in the Mojave Desert. Similar to R. Californica.
Baja Rose (R. minutifolia). Grows in Baja and the southern section of San Diego. It has very small leaves and bright pink flowers with prominent yellow stamens.

The information in this column was drawn largely from Wikipedia and the website of Las Pilates Nursery, a great source of information about California native plants.

This photo is from Suisun Marsh page of the California Department of Water Resources website. The photo shows Rosa Californica’s rampant growth and numerous rose hips. This plant can be controlled in a garden, through seasonal (and diligent) pruning.

Making More Succulents

Posted on October 6, 2013 by tomkarwin

Two recent events—the fall sale of the Monterey Bay Area Cactus and Succulent Society in San Juan Batista and the annual Succulent Extravaganza in Castroville—attracted throngs of gardeners who gained new appreciation for the variety and appeal of succulent plants, and brought home great numbers of plants.

By bringing hundreds of small succulent plants for sale at these events, the organizers provide an important service for gardeners. They also demonstrate that making more succulents is really easy. Anyone can do it!

Propagating succulents avoids the costs of buying plants, particularly for mass plantings or large arrangements that feature many of the same plants.

This practice also appeals to gardeners who want to renew a succulent plant that has grown leggy, or too large for the intended location.

A third reason for large-scale propagation is to create plants for giving or selling to other gardeners.

Popular methods for propagating succulent plants are based on stem cuttings or leaf cuttings. Today’s column focuses briefly on those methods.

Step One: Make the Cutting.

Any succulent plant that has an elongated healthy stem can be propagated. Using a sharp knife or razor blade, cut a two-to-four inch piece from an actively growing stem. Remove the lower leaves, if any, and dip the stem in rooting hormone (available in garden centers). Then, rest the cutting in a shaded location for up to a week while a callus (or callous) forms to protect the cut end from harmful microbial life.

Make a leaf cutting in the same manner: cut or break a full vigorous leaf from the upper half of the plant, dip it in rooting hormone, and allow it to form a callus.

Echeveria plants and some other succulents form rosettes of leaves. These can be cut from the plant with up to an inch of stem, and propagated just like a stem or leaf.

Step Two: Start the Cutting

Prepare a very fast-draining medium, e.g., 80% pumice or perlite and 20% potting soil, insert the cutting and place it in a warm location with indirect sunlight. Water with tap water that has had time to release it chlorine, or use distilled water. Pour gently from above or absorb from the bottom. Mist the cutting with distilled water daily and maintain a humid atmosphere with a plastic tent or other method, but let the plant dry out before watering.

Step Three: Plant the Rooted Cutting

After several weeks, when the cutting has developed roots, transfer it to a larger container filled with 75% pumice or perlite and 25% potting soil.

In a future column, I’ll describe other propagation methods, including grafting, and planting seeds, offsets or plantlets.

More

Here’s a project that calls for a large number of small succulents plants. I lifted this image from Debra Lee Baldwin’s newsletter, which has step-by-step instructions for creating your own similar display. I expect neither she nor Roger’s Garden will object to my use of this photo. (It helps to have a nice container on a pedestal, but Debra says, correctly, that the container should not be featured, but rather treated like the frame for the picture.

When to Plant Flowering Plants

Posted on February 22, 2013 by tomkarwin

The gardener planning to expand or renew a collection of flowering plants should know the preferred times to buy and install.

For perennials, a good time to plant is during the early part of the rainy season. This schedule relies on the rain to water the plants while they establish roots before flowering in the spring. In the Monterey Bay area, the rainy season begins typically in mid-October or early November and continues through March, with the greatest rainfall in January.

For some popular flowering plants, the ideal planting times relate to dormancy periods. A rule of thumb is to buy and install such plants when they are on sale by gardening groups.

The Monterey Bay Iris Society holds an early sale of tall bearded iris rhizomes at The Garden Faire, on the first Saturday of the summer season. This year, the Faire will be on June 22nd. The Society has two larger sales in the first half of August. The Society has its show early in May, when gardeners can see tall bearded irises in bloom.

Other kinds of irises have annual cycles that differ from the tall bearded irises. The rhizomes of beardless irises, e.g., Japanese, Louisiana, Siberian and Spuria irises, are planted in early October. Divisions of California native irises are planted around the end of August.

The Monterey Bay Iris Society does not offer beardless iris rhizomes or California native iris divisions at its sales, but some garden centers offer these plants. Also, the Society for Pacific Coast Native Irises sells seeds during the fall of each year; in 2012, the last day to order seeds was December 31^st. Seeds can be planted during the winter months, with blooms expected early in April.

Another local example is the Monterey Bay Dahlia Society, which has its primary sale in early April. The society’s annual show is held typically at the end of August.

Roses are most often sold during their dormancy as bare root plants from late fall through the winter months. Garden centers and mail order nurseries are the principal sources. The Monterey Bay Rose Society does not sell rose plants, but it has an annual show in May, where gardeners can see roses that grow well in the Monterey Bay area.

Gardeners often buy annuals in the spring when they are in bloom. While it’s helpful to see the bloom before buying, the plant might be peaking in the garden center and ready to decline in the garden. A better plan is to buy six-packs of annuals earlier in the spring, and let them bloom in the garden.

Visit ongardening.com for more ideas about planting times. Be a smart plant buyer, and enjoy your garden!

For planning a vegetable garden, a helpful resource is the Spring Garden Planting Guide, published by Mother Earth magazine. It’s available online. Click here for the Guide and a Spring Garden Worksheet.