Color in the Winter Garden

A good practice is to walk through your garden occasionally to see what is succeeding, and what might need changing. It’s rewarding to visit your plants in the spring, but the winter months (now) are when we look for dormant season instances of attractive color, form or fragrance.

In the Monterey Bay area, the dormant season brings nothing like the severe conditions experienced in some other parts of the United States, but our gardens still rest at this time, and might present only limited interest.

It doesn’t have to be that way! There are many plants that can enhance our gardens while other sleep, when we plan for all season interest.

A first step is to take note of plants that are already in your garden, and looking good right now. They might be providing attractive blooms or interesting foliage, taking the center of attention while others have dropped their leaves or died to the ground.

You could supplement the tour of your own garden with a walk through your neighborhood to see what looks good in nearby gardens. That approach automatically identifies plants that would thrive in the climate and soil conditions of your garden. It can also be a good excuse to meet new people, to ask them about their gardens.

My garden, while not a true all-season display, still has several plants that are attractive during the winter months. For example, succulent plants, which have done well during our drought period, can maintain their appearance during dormancy.

I recently renovated a small bed of Mexican succulents, and the plants are looking good. They will produce blossoms later in the year, but the forms and colors or their foliage works well year-round. The recent addition of a large Talavera bowl, recently added, serves to mark the bed’s Mexican theme.

Talavera pottery, offered by many garden stores, is a style of glazed ceramic pottery that dates to the Italian Renaissance. Authentic Talavera items are from the Mexican city of Puebla and nearby communities, but imitations (which includes my own piece) are widely available. Imitations from other parts of Mexico are properly identified as Maiolica, which refers to the decorative style.

Other plants that are starring during the winter include a Purple Lilac Vine (Hardenbergia violacea), an Australian native, now covered with small violet flowers; an enormous Candelabra Plant (Aloe Arborescens) from South Africa, blooming later than others in the area, and a favorite, a Variegated Winter Daphne (Daphne odora ‘Aureomarginata’), which offers both colorful evergreen foliage and a sweet fragrance that highlights the season.

Daphne odora 'Aureomarginata'

Daphne odora ‘Aureomarginata’

When provided good drainage and afternoon shade, daphnes are reliable performers for years until they suddenly and without apparent cause, give up. An older specimen recently showed arrested development: flower and leaf buds simply didn’t mature for months. After quizzing three knowledgeable friends, without success, I removed the plant (making space for another fuchsia). By this time, I already had three replacement daphnes growing nearby, so I still could enjoy the wafts of fragrance this year.

Prepare now to bring new interest to your garden for next winter with more seasonal bloomers and evergreen foliage, either adding specimens of existing plants that you like or bringing in good performers that you have seen in nearby gardens. Winter gardens can be very pleasing environments.

More

A quick Internet search or a visit to your local library or bookstore could lead to useful lists of winter-blooming plants. For example, one good source of information is Dan Hinkley’s book,  Winter Ornamentals.

Adding Unexpected Plants to Your Garden

This column presents a case study of adding an unexpected and unfamiliar plant to one’s garden.

A friend gave me a plant that had outgrown its container, and no longer had a place in its previous home. My friend didn’t have a name for the plant, but a neighbor’s garden has a related species: the photo shows much longer leaves than my gift plant, and the potential to grow rather large.

Dyckia

I had never grown a plant like this one, so I was immediately interested. Here is a suggested intake process.

First, inspect the plant visually to check that it is healthy and free of disease or pests. This plant had some dieback from normal aging and outgrowing a large container, but otherwise looked healthy. I gladly accepted the gift.

Identification should be the next priority. I had seen this plant in four-inch pots, and knew it as a Dyckia, but learning the genus and species of a new plant can be challenging. This plant doesn’t appear in Sunset’s Western Garden Book, a convenient reference. In such cases, asking other gardeners or garden center staff can be the best strategy.

Then, examine the plant’s size and characteristics. This Dyckia develops several rosettes eight-to-twelve inches in diameter. Each rosette is comprised of many thin leaves up to eight inches long, with very sharp terminal spines and numerous sharp teeth on both sides. (My neighbor’s magnificent Dyckia has leaves up to two feet long!) The plant is attractive, but neither welcoming nor easily handled!

Considering both this plant’s mature size and hazards, I concluded that it should be should be three feet from any walkway, but still close enough to appreciate its intricate leaf structure.

Also, it should not be under a tree, as it would be difficult to groom dropped leaves from the Dykia’s spiny cluster.

Then, learning about the plant’s cultivation needs will guide planting and future care. An Internet search for “Dyckia” brought me these websites: Wikipedia; Bromeliad Society of Houston; Yucco Do Nursery; Annie’s Magic Garden; and Dyckia Brazil.

Dyckias, I learned, are native to Brazil, members of the Bromeliad family, and related to pineapples (Ananas comosus), Puyas, Tellandsias, and Bilbergias. There are some 158 species of Dyckias.

After comparing my specimen’s appearance with others on the Internet, I concluded that it is D. fosteriana, which is a popular species. This plant hybridizes easily in nature and in human hands, so many cultivars are available. Confident identification requires a specialist.

The Dyckia lacks internal water storage tissue, so it’s not a true succulent, but it will go dormant in response to a lack of moisture. It prefers full sun but will manage partial shade, and has exceptional tolerance for freezing weather. It is pest-free, although snails will nibble at tender flower shoots. Generally, the Dyckia is a sturdy and trouble-free plant.

Dyckias reportedly do not like transplanting during the winter, but I proceeded still to separate and pot up six offsets (”pups”) for gifts to others, and to put my new plant in the ground. I’ll learn how well it responds.

My garden lacks a bed for Brazilian plants. I accommodated this unusual new plant by redefining my existing Chilean bed as Chilean/South American.

Avid gardeners should welcome unexpected, unusual and attractive gifts to their gardens. A systematic process can help to place the plant well and to provide the care needed for its success. New plants are gardening adventures!

Twelve Ways to “Plant-Mass”

An important guideline for amassing plants in your garden is to plant when seasonal rains will water the plants as the establish roots and prepare for blooming in the spring. So, a good time to add plants to your garden (or to find a late gift) is right now.

Here are twelve ways to succeed in that enterprise.

  1. Plan to fill an existing space in the garden. Impulsively buying plants that catch your eye in the garden center can result in specimens that are too large or too small for spaces that need filling, or won’t complement plants next to those spaces.
  2. Focus on plants that will add to your landscape style or theme. There are many alternatives to randomness in garden design. An explicit theme or style in your garden provides direction in the hunt for new plants, and adds coherence to the look of the garden.
  3. Choose plants that will thrive in your garden’s environment. Most important is your U.S. Dept. of Agriculture climate zone, but also consider elevation, sun exposure and soil type.

    Crassula argenta

    Jade Plant (Crassula argenta) in a one-gallon nursery can

  4. Select plants of an appropriate size for the spot where they will grow. A common error is to install a plant that will outgrow its location.
  5. Look for plants that are pest resistant. With fuchsias, for example, a good choice would be a variety been bred to resist the Fuchsia Gall Mite (Aculops fuchsiae), a pest that’s difficult to control.
  6. The logical corollary is to examine plants that you might buy to check for any evidence of “livestock.” The symptoms (e.g., chewed leaves, creepy-crawlers or their eggs on the underside of leaves) are usually unmistakable, but if you have any uncertainty, choose a plant that’s symptom-free.
  7. Similarly, look for plants that are disease resistant. Several varieties of roses are both beautiful and resistant to powdery mildew and black spot. Why would you want to struggle with those diseases?
  8. Again, before buying a plant, check for any sign of disease, or anything other than good health. Garden centers screen their plants diligently, to protect customers and their own reputations, but problems can be missed. This is most possible with amateur plant sales.
  9. More and more, gardeners prefer plants that are free of toxic synthetic chemicals. Growers are beginning to label plants that have been grown without the use of neonicotinoids (“neonics”), for example, which appear to be harmful to bees. If the label doesn’t give assurance, ask!
  10. To minimize your plant-buying expense, favor the garden center’s smaller plants. They should be well rooted, rather than freshly transplanted. In your garden, they will grow quickly to reach the size of more expensive plants.
  11. On the other hand, to achieve an immediate effect, favor the larger plants. You will be paying the nursery for caring for the plant for months or even years, but the results may be worth the cost. An added benefit is seeing a well-grown plant’s structure.
  12. Before buying a plant, especially one that fills its container more than others, check for healthy roots. Gently pull the plant from its container to examine roots for healthy color (usually white) and ample space in the container. Plants left too long in a container become root-bound, which can hamper their growth. On the other hand, such plants often could be divided into two or more for the price of one.

 

Dormant Season Projects

The dormant season does not have an official beginning to mark on a calendar, but depends on a combination of factors, beginning with the individual plant’s biological clock, with which the plant responds to day-lengths.

Another important environmental factor is temperature: lower temperatures trigger dormancy, and higher temperatures can stimulate growth. Climate change has modified the annual cycles and geographic distribution of many plants, and will continue such changes. Phenology is the study of periodic plant and animal life cycle events

Rather than delving into the science of dormancy, let’s consider seasonal projects for the gardener. There are many priorities to schedule over the next few months.

Pruning

As the leaves fall, and the “bones” of your trees and shrubs are exposed, look for ways to improve them through pruning. In general, use sharp tools, begin by removing branches that are broken or diseased, and don’t remove more than one-third of the canopy in one year. As is often true in gardening, there are exceptions: for some shrubs, severe or renewal pruning is appropriate. Extensive pruning of roses, for example, stimulates new growth and abundant blossoms. Several other multi-branched shrubs, e.g., salvias, can be cut to their primary structure or to near the ground before spring growth emerges.

Many gardeners are hesitant about pruning, concerned that they could hurt their plants. Pruning can be done badly so a little time with a pruning book would be instructive. The positive perspective is that pruning improves a plant’s form and stimulates new growth.

pruning fig 1

Pruning during the dormant season

The photo is from the University of California publication, Pruning Small Trees and Shrubs, which is available free online.

A good approach includes observing pruning’s effects during the early spring.

Other Projects

  • Walk through the garden with a critical eye, to spot opportunities for improvement.
  • Transplant or give away plants that have grown too large, or not working in the landscape.
  • Install new plants now, to let the rains irrigate them as they establish roots.
  • Add mulch to cover any bare ground between plants.
  • Plant a cover crop in any fallow planting area.
  • Force a bulbous plant to bloom indoors. Paperwhites (Narcissus papyraceus) are popular, but are so strongly fragrant that restraint can be prudent, i.e., don’t grow a lot.
  • Sharpen your garden tools, or have them sharpened professionally.

Mark your Calendar for the New Year

January 8, 9 & 10 — The 42nd Annual Santa Cruz Fungus Fair, at Loudon Nelson Community Center, Santa Cruz

January 10 — Annual Scion Exchange, Monterey Bay Chapter, California Rare Fruit Growers, at Cabrillo College, Aptos

Late News: Broom versus Leaf Blower Challenge!

The broom versus leaf blower challenge between Ken Foster (on the broom) and Brent Adams (on the leaf blower) will take place Friday December 11th at high noon next to the Westside New Leaf Community Market, at the corner of Fair Avenue and Ingalls Street in Santa Cruz.

Gasoline-powered leaf blowers pollute our environment, disturb our peace, and change our climate. They might be justified for their seeming efficiency, but that too has been questioned. The Broom versus Leaf Blower Challenge, designed as a fair completion, is worth witnessing (sorry about the late announcement). I’ll report the results in next week’s column.

Rethinking a Planting Bed

There are a few reasons for a gardener to re-think a planting bed: inspiration for a new approach, boredom with the old approach, overgrown plants (and an invasion of weeds), or a desire to improve the aesthetics.

For one of the beds in my garden, I have the urge to edit the existing plants to satisfy to a thematic concept: Mexican Succulents.

At least ten years ago, I established this bed, which is not large (almost forty square feet) but prominently located in the garden. An edge of larger stones supports a raised planting area, which is ideal for succulent plants. Over time, I installed a variety of succulent plants.

When I look at this bed now, the mix of plants leaves me uneasy. During the intervening years, I have become interested in thematic collections of plants, with an emphasis on county of origin. From that perspective, this bed was a horticultural hodge-podge.

For some gardeners, that reaction might suggest an unhealthy obsession with order, but that’s OK. It’s my garden and I can do what I want.

This concern, which has been lurking in the background for a while, was activated recently by two events. First, at a meeting of the Monterey Bay Area Cactus & Succulent Society, I attended a presentation on Agaves, a southern California succulent. Then, a friend gave me an Agave parryi (Mescal Agave), which is also from southern California and northern Mexico.

I already knew most of the plants in this bed were Mexican or southern Californian, the featured plant being a Dasylirion wheeleri, also called a Desert Spoon.

Dasylirion wheeleri

Dasylirion wheeleri, a succulent plant from Mexico, with a large South African succulent, an Aloe arborescens, in the upper left background.

My concept of “Mexican Succulents” includes southern California, because plants don’t recognize political boundaries, and besides, historically, Mexico included what we now know as southern California.

My first step toward that objective was to inventory the existing plants, to determine which should be relocated. I identified plants from South Africa: Crassula tetragona (Miniature pine Tree), Crassula argentea (Jade Plant), and an enormous Aloe arborescens (Torch Aloe), which has been screening my compost bins.

I also found plants from the Europe and the Mediterranean basin: a self-seeding Euphorbia characias wulfenii (Mediterranean Spurge), a few unidentified plants: Sedums, Sempervivum, and Aeonium.

The task, then, is to move the South African succulents to another bed that already has that theme and to move the others to the bed for Mediterranean Basin plants. The biggest challenge will be to remove the South African Torch Aloe, which needs a larger space than is available elsewhere in the garden, and to find another screen for the compost bins. Aloes are hard to kill, so I could give away cuttings at the curb for other gardeners.

Then, I could assess the newly dedicated bed for Mexican Succulents and begin filling in the empty spaces with new plants, beginning with my one Agave parryi. I probably will avoid collecting agaves because they have sharp terminal spines, are monocarpic (they die after flowering), and produce lots of offsets (pups). There are many other Mexican succulents to explore.

A good practice is to tour your garden occasionally to consider if a bed could be improved by editing the plants, or starting over entirely. It’s best to focus on a limited area, rather than taking on the entire garden at one time. Renewing a planting bed should be a creative exercise and could lead you into a new area of gardening.

Adventuresome Gardening

Regular readers of this column know of my interest in plants from the world’s summer-dry climates, also called the Mediterranean Basin regions. Many plants from these exotic regions will thrive in the Monterey Bay area, and provide attractive and exciting alternatives to the garden center’s humdrum horticulture. Cultivating such plants is the enterprise of adventuresome gardeners and seekers of botanical thrills.

There are countless examples of such plants to be discovered among the selections of mail-order nurseries, either in published catalogs or online. To be fair, local garden centers also might have a few offbeat offerings; it’s worth asking the staff to mention any unusual plants.

One candidate for a featured position in the landscape is the Puya, which is one of about fifty-seven genera in the Bromeliad family. Just about all bromeliads are native to the tropical Americas. About half of the species are epiphytes (growing on air and rain), some are lithophytes (growing on rocks), and the rest are terrestrial (growing on earth). The most familiar of the terrestrial bromeliads is the pineapple (Ananas comosus).

Another terrestrial bromeliad is the Puya. This genus includes about 210 species, several of which are native to Chile, where they have the common name chagual.

One of the Chilean Puyas is the Blue (or Turquoise) Puya (P. berteroniana). This plant grows a flower spike about six-to-ten feet tall, and has exceptional landscape value because of its extraordinary 1.5” waxy, metallic blooms of an unearthly emerald-turquoise color, with contrasting bright orange stamens. The blooms hold blue, syrupy nectar that attracts hummingbirds, bees and other pollinators.

Puya berteronianas

The Blue Puya can be found in some public gardens. I viewed several fine specimens, and took this photo, about one year ago, in the Australian National Botanic Gardens, in Canberra.

Locally, the Blue Puya is in bloom now at the UCSC Arboretum. The blooms do not last long, so to see one of nature’s most extraordinary flowers, visit the UCSC Arboretum soon. For information and pictures, visit arboretum.ucsc.edu/ and click on “What’s Blooming.”

The Chilean bed in my garden includes two quite young examples of this genus: a Blue Puya (P. berteroniana) and a Silver Puya (P. coerulea). These are slow-growing plants, now years away from blossoming in my garden. While they are not yet pleasing my eyes, they are already trying my patience (a little) and piquing my imagination.

Annie’s Annuals lists nine Puya species, but current availability includes just three. Similarly, the wholesale nursery San Marcos Growers lists eight Puya species, with just three currently in production. Your local garden center could special-order plants from these nurseries, or another preferred source. Search the Internet by botanical name for information to share with garden visitors.

You certainly can keep your garden’s tried and true selections, but consider adding exotic plants to enrich your landscape.

Exotic Bulbs for Spring Bloom

As we proceed into autumn, the gardener’s thoughts turn to the gratifying display of spring bulbs.

If your garden already includes bulbs that bloom each spring, and you have all you want, relax and let nature do its thing!

If you want more blooms to brighten your spring, however, plant bulbs during the next few weeks.

The general rule is to plant bulbs before the ground freezes, but Monterey Bay area gardeners can only imagine a freeze to schedule bulb planting.

In this temperate climate, bulbs that do not require vernalization (dormant period chilling) are most convenient.

There are many bulbs in this category, including the popular narcissus, plus allium, colchicum, crinum, crocus, gloriosa lily, hyacinth, kaffir lily, muscari, snowflake, spider lily, and watsonia. Most of these are members of the large lily family (Liliaceae), which also includes the tulip.

Several species tulips require little chilling during their dormant period, including Tulipa bakeri ‘Lilac Wonder’, T. clusiana (Lady Tulip), T. saxatilis (Candia Tulip) and T. sylvestris (Florentine Tulip). All these produce demure, colorful blooms.

By contrast, hybridized tulips, with larger blooms and taller stalks, require chilling. Some helpful suppliers offer pre-chilled bulbs of hybridized tulips.

Bulbous plants are native to the globe’s five summer-dry climates, particularly the Mediterranean region, South Africa, and California. Adventuresome gardeners can have a great time growing spring bulbs from one or more of these areas.

Triteleia laxa

Triteleia laxa ‘Queen Fabiola’

Such projects require some research. The larger mail-order bulb suppliers offer at least a few bulbous species from faraway places, among the mainstream varieties, but their catalogs have inconsistent information about the country of origin.

Here are sources of bulbous plant information, by country of origin:

  • Pacific Bulb Society’s Wiki, a volunteer-written on-line encyclopedia of flowering bulbs, with photographs.
  • Telos Rare Bulbs, a mail-order nursery in Ferndale (on the California coast, near the state’s northern border), offers a great selection of native plants of California, South America and South Africa.
  • Mediterranean Area: Alpine Garden Society lists specialized books on bulbous plants, including Bulbs of the Eastern Mediterranean, by botanist Oron Peri. The bulbous plant cognoscenti are thrilled with this newly released book.
  • South Africa: The Color Encyclopedia of Cape Bulbs (2002), by John C. Manning, Peter Goldblatt, and Dee Snijman.
  • Chile: Few bulbous plants are native to Chile, including Glory-of-the-Sun (Leucocoryne) and the striking—and rare—Blue Chilean Crocus (Tecophileae cyanocrocus). Both are available from Telos Rare Bulbs. For the short list, visit Chileflora (click on Seeds Shop/Life Form: Bulbous Plants) or Sacred Succulents (click on Rare & Beneficial Plants from Chile), a small, family-run business in Sebastopol, California.
  • Australia: Gardeners of the land down under cultivate several bulbous plants that originated in other areas, but apparently few if any that are native to Australia. (If you know of any, let me know.) The region’s popular Chocolate Lily (Dichopogon strictus) is attractive, but it’s tuberous, not bulbous.

Screen Shot 2015-11-14 at 12.20.55 PMThrough a recent search of the Internet. I found a new book by Attila Kapitany, Australian Native Bulbs (2015). This book highlights eight native
species of bulbs, corms, and tubers, and “discusses many more.” It is available on eBay with shipping costs for the interested buyer to discover.

 

 

 

 

Cultivating exotic bulbs can be challenging, intriguing and rewarding, as beautiful and out-of-the-ordinary blooms appear in the spring.

***

Comments and Questions are Welcome

 

Landscaping with Succulents

As we await El Niño rains, the Monterey Bay area’s familiar rainy season is already late in starting, and we feel the pull of long-term perspectives on gardening.

Let’s consider landscaping with succulents plants, which are gaining appeal for their interesting foliage forms and colors, ease of cultivation and propagation and of course drought tolerance.

Many succulent plants can hold their own in the garden as specimens or aesthetic statements, but when we group several plants, they relate to one another in various ways and we have a landscape, either by design or by chance.

Tiered Succulent Display

Tiered Display of Succulents in Sidney, Australia

Landscaping by chance is often popular, but with a little planning, gardeners can succeed with more deliberate methods.

Designing with plants involves individual preferences and styles, which we always respect. There are, however, a few broad guidelines to consider.

The first of these is “taller plants in back,” which is about visibility. Take the time to learn the mature height of each plant. Here is information sheet from succulent expert Debra Lee Baldwin, listing popular succulent plants by height: Instant Gardens.

Another organizing guideline is to group plants by their watering needs. This technique, called hydrozoning, works with nature (always a good idea!) and makes garden maintenance easier.

Using this technique requires knowing the watering needs of the succulent plants in your landscape. All succulent plants need some water, particularly during their growth periods. They need much less during dormancy.

The two broad categories of succulent plants are the “winter dormant,” i.e., plants that grow during the spring and summer, and the “summer dormant,” i.e., those that grow mostly during the fall through early spring. Here is a link to winter dormant and summer dormant succulent plants.

The landscape designer also could group plants by county of origin. Such grouping is a step toward creating plant communities, which are combinations of plants that are found in natural settings. Such combinations reflect the plants’ common needs for soil, exposure, climate and other factors. Gardening in this way involves detailed cultivation methods. Grouping plants by country of origin is relatively easy, while respecting nature and developing an interesting landscape. The avid gardener can discover a plant’s country of origin from some books and plant labels, or by entering the plant’s botanical name in wikipedia.org.

Finally, consider combining succulent plants with grasses, which are another category of drought-tolerant plants. Grasses typically respond to severely dry conditions by going dormant, rather than by storing moisture, and grass-succulent combinations are seen in natural settings. The benefit of combining succulents and grasses is primarily in the aesthetic effect of contrasting the succulent’s fleshiness with the grass’s wispiness. To learn more about grasses, see the book, The American Meadow Garden (2009), by John Greenlee and Saxon Holt.

For more comprehensive guidance, Debra Lee Baldwin’s book, Designing with Succulents (2007), provides inspiring ideas for planning your own succulent garden area.

Preparing for long-term water shortages certainly includes defensive strategies, but your preparations can include landscaping with succulents as an absorbing and creative exercise.

Evolution of the Community Garden

I never expected to be impressed by a housing development in the San Jose area, but late in September of 2015, the City of Santa Clara launched an extraordinary project that City Council member Lisa Gilmor said is“…the first of its kind for Santa Clara. I don’t think we’ve done anything like this in the past.”

The Council selected a developer, The Core Companies, to lead master planning and development of a six-acre site on Winchester Boulevard, near the Valley Fair and Santana Row shopping centers.

Win6 Project - conceptual

Core/CNGF Project – Conceptual

The project concept combines housing with several familiar elements: a small organic farm, community gardens, a children’s garden, California native plant edible landscaping, roof gardens, solar energy production, a farmer’s market, a rainwater garden, an outdoor kitchen, and much more.

Overall, the project qualifies as an “agrihood,” a newer idea that focuses residential housing on a working farm, rather than a pool, tennis court or golf course. An agrihood also engages the residents in creating a sustainable food system for the entire community.

This concept could be appealing to people of all ages, but the United States has only a short list of existing agrihoods (for examples: http://tinyurl.com/ox4to7h). The Santa Clara project appears to be the only agrihood in an intensely urban environment, and an exceptional showcase of several ideas in sustainable gardening.

The City of Santa Clara selected this project among eight competing proposals because of its creativity, vigorous community support and the history of the site, which had been part of an agricultural research station operated by the University of California, beginning in the last 1950s.

A visionary neighbor, Kirk Vartan, galvanized community support for this project. He found a creative and knowledgeable ally in Alrie Middlebrook, a landscape designer and leader of the California Native Garden Foundation, a non-profit group that demonstrates innovative gardening ideas and supports the development of school gardens. Middlebrook’s ideas are evident in the rich array of gardens in this agrihood, which has been called the Core/CNGF project.

The California Native Garden Foundation will be involved in managing the project’s urban agriculture open space. (Full disclosure: as a long-time member of the CNGF’s board of directors, I have had both opportunities to monitor this project’s development during the past several months, and a very limited role in its creation. The CNGF board’s primary role is to review schools’ applications for the planning and development of learning gardens.)

Agrihoods could become the evolutionary next step beyond community gardens and community-supported agriculture. Through this project in nearby Santa Clara, we can see the leading edge of innovative strategies for relating research-based gardening and community relationships.

Leaf Blowers

In recent columns, I have addressed soil health as an emerging issue in global climate change, and described ways in which residential gardeners could participate in solutions to this high-level priority. The most important strategies for home gardeners in this connection include using mulches and cover crops to protect the soil from the elements; avoiding uses of synthetic chemicals, which attack the soil microbiome, and favoring regionally appropriate plants, including (for the Monterey Bay area) plants that are native to California and other dry-summer climate regions.

Today’s column focuses on uses of gasoline-powered garden equipment: leaf blowers, lawnmowers, lawn edgers and chain saws.

This equipment contributes to climate change and air pollution. The typical device uses a two-stroke engine, which, by design, does not burn the fuel efficiently, and instead emits large quantities of carbon monoxide, nitrous oxides and hydrocarbons. These emissions contribute to smog formation, climate change and acid rain, and hydrocarbons in particular can be carcinogenic.

Small trucks and passenger cars also produce worrisome emissions, but gasoline-powered garden equipment emit them at much greater rates. For example, leaf blowers produce 100 to 300 times as many hydrocarbons as does a small truck or passenger vehicle. Garden equipment with four-stroke engines perform significantly better, but still far worse than car engines.

In terms of environmental pollution, these are very dirty devices.

The California Air Resources Board has stated, “Potential health effects from exhaust emissions, fugitive dust, and noise range from mild to serious.”

Fugitive dust includes organic debris and “particulate matter,” which can include a variety of potentially nasty organic and chemical stuff that people should not breathe.

Noise pollution effects include annoyance, hearing loss (particularly by equipment operators), and a range of psychological impacts.

For more information, visit the website of Zero Air Pollution (www.zapla.org). This southern California organization details the range of health hazards associated with this garden equipment, wherever it is used.

Leaf blowers sometimes are used to clear organic materials, and leave bare soil. Making nature “tidy” in this way exposes the soil to the damaging effects of the sun and wind. The regeneration of healthy soil requires maintaining cover of vegetation or mulch materials.

Here are recommendations for ecologically appropriate uses of garden equipment.

  1. Minimize or eliminate the use of gasoline-powered devices in favor of manual equipment. Use rakes and brooms to clear leaves, a push lawnmower to cut grass, a long-handled edger to trim lawns, and a handsaw to prune limbs. These tools are consistent with a contemplative approach to gardening, and provide desirable exercise.
  2. When the task requires too much time and effort for manual equipment, use electrical devices. Battery technology is advancing to enable longer operation of small garden equipment; corded devices, although cumbersome, work quite well. (My corded leaf blower moves leaves nicely.)
  3. Negotiate with your “mow, blow & go” garden maintenance contractor to use manual equipment whenever possible. This might require a small rate increase, but everyone will be better for the effort.

Continue reading