Spring Show of Tall Bearded Irises

The tall bearded iris is among the most rewarding drought-tolerant plants, and right now is the ideal time to plan for irises in your garden.

Big Picture (Ghio, 2014)

Big Picture (Introduced by hybridizer Joe Ghio, 2014)

There are several iris genera and species, and several varieties of the bearded iris. The tall bearded iris is the most popular variety, the result of the past fifty or so years of hybridizing. The hybridizers’ patience and creativity have yielded an amazing range of colors, color combinations, patterns and blossom forms, as well as plants with great vigor, productivity and in some cases repeat blooming.

The early fall is the time to plant irises, but they are blooming now, in the early spring, making this the time to learn about the varieties and choose plants to add to your garden.

The occasion for this timely and enjoyable pursuit is the Monterey Bay Iris Society’s annual show, scheduled for this weekend. This event features the best plants grown by local gardeners. There are a few “ringers” among those displaying their plants (people who grow irises commercially), but they are also locals and active participants in the Society’s ongoing educational programs.

A room full of top quality irises can be overwhelming to those not already familiar with these striking plants, and perhaps intimidating. You might even think, “How could I grow such impressive plants?” A good defense to such feelings is to read “How to Grow Tall Bearded Iris,” which is freely available online from the MBIS.

This two-page tutorial will make clear that irises are among the easiest great garden plants to cultivate and provide the confidence to bring them to your garden.

Another very good preparation for this show is to look through the Show Program, which is also available online from the MBIS. This eight-page document is packed with information about the categories of irises in the show, the exhibition rules, and the awards to be won. The Show Program provides an excellent orientation to the blossoms to be seen at the show.

The Program also includes information about membership in the MBIS and a calendar of the Society’s sales in June and July, anticipating planting in August and September.

This show is conducted according to the rules of the American Iris Society, and a team of expert judges will evaluate the blossoms. This process occurs on Saturday morning, before the show is open to the public, so visitors will see which blossoms have received first, second or third place awards. Visitors to the show are invited to vote for the People’s Choice Award.

Irises can beautify your garden!

If You Go

What: Spring Iris Show: “2016 Spring Rainbow”

Who: Monterey Bay Iris Society

When: Saturday, April 23, 1:00 to 6:00 and Sunday, April 24, 10:00 to 5:00

Where: Louden Nelson Community Center 301 Center Street, Santa Cruz, CA

Admission: Free for all visitors

Information: “How to Grow Tall Bearded Iris” and Show Program: http://www.montereybayiris.org/

Book: The Art of Gardening

 

My short list of readings for avid gardeners has just become longer.

The book is The Art of Gardening: Design Inspiration and Innovative Planting Techniques from Chanticleer (Timber Press, 2015).

Chanticleer is an exceptional thirty-five acre public garden, in Wayne, Pennsylvania, thirty minutes NW of Philadelphia. It was established a century ago at the home of the Rosengarten family, and became a public garden twenty years ago.

The book’s authors include R. William Thomas (Chanticleer’s executive director and head gardener) with fifteen members of the garden’s staff, including seven horticulturists. Rob Cabrillo created the photographs, a prominent feature of the book.

The Chanticleer garden reportedly continues the original layout created in the early 1900s by landscape architect Thomas Sears; most of the floral and garden development has been accomplished since 1990, when the owner passed.

Chanticleer includes fifteen distinct areas. These are not enclosed, as “garden rooms” might be thought of, but well-defined small spaces within the sprawling property, separated in several cases by lawns. Each unique area has its own gardener who has freedom to manage the ever-evolving design of the landscape, while maintaining the integrity of the overall garden, the area’s relationship with other areas, and (quoting the book) “the union between plant and site. “

I am still working on this concept of “union” because all the plants in my garden are fully unified with their site, but never mind.

This arrangement of spaces and the relative autonomy of the gardeners makes Chanticleer an unusually rich resource for the home gardener. Each of the fifteen relatively small spaces displays design concepts and plant combinations that are ready for adoption or adaptation within the constraints of the typical home garden.

If Chanticleer were designed and managed by a single vision, it would be less interesting and less useful to the visitor.

The book has two major sections: Design and Plants. It also includes minor sections: introduction, afterword, suggested readings, index and a group photo of the several authors, with brief biographical notes.

The Design section (85 pages) describes the site, the arrangement of the fifteen smaller gardens, the use of built structures, the use of patterns to unify the overall garden, the evolutionary approach to garden design, uses of color, and specific examples of design concepts.

The much larger Plants section (205 pages), includes some bylines for the various writers, but likely was written mostly by the co-authors. This section includes observations about the uses and cultivation of individual plants, revealing the staff as a group of thoughtful plant lovers. They have the advantage over many home gardeners of careers in gardening and the opportunity to focus on their plants through annual cycles and over the years. (Speaking for myself, life’s many distractions interrupt the continuity of the gardening experience.)

Despite these multiple voices, the book reads easily, with consistent language throughout. This quality surely reflects the work of the editor.

The avid gardener would benefit from a few pleasant hours with The Art of Gardening, and from having it readily available on the bookshelf. A visit to this extraordinary garden should be included with a future opportunity to fly to the east coast.

As always with garden information from Other Lands, consider climatic and environmental differences with the Monterey Bay area.

GMO Labels Are Important

As reported last week, the U.S. Senate rejected a recent legislative attempt to ban states from requiring labels to identify food products made with ingredients that include genetically modified organisms (GMOs).

This was a victory for the vast majority of consumers, who have been demanding to know what is in their food. Food producers have insisted GMOs are nutritionally no different from so-called conventional foods, GMO labels would suggest that such foods are not as good and some consumers would avoid them.

The food producers, working through the Grocery Manufacturers Association had spent millions of dollars to oppose state initiatives to require these labels. State initiatives in California and Washington failed narrowly, but Connecticut, Maine and Vermont passed similar initiatives. Vermont’s law will go into effect on July 1st of this year, prompting the federal preemption strategy.

With the failure of the Senate bill, several major food producers announced plans to label foods with GMO ingredients. Campbell was the first to announce. It was soon joined by General Mills, Kellogg, Mars, and Conagra Foods. They had previously opposed GMO labeling, and are now calling for uniform national guidelines for such labels.

These large companies are taking this action as a clear business decision. They are sure that Congress will respect the clear and strong position of consumers, they expect additional states will require labels, and they certainly don’t want a hodge-podge of state-by-state requirements.

Food producers now will do all they can to persuade consumers that GMO foods are both safe and good for you. This is “Plan B,” the fallback position for when they could not ban labeling.

At this juncture, consumers should learn all the reasons why GMO labels are important.

First, U.S. Food & Drug Administration has concluded that GMO foods are the same nutritionally as non-GMO foods, but the FDA relies instead on research conducted by the food producers and does not conduct its own research. Independent scientists have argued that manipulating genes is not an exact science and could have unintended consequences. Steven Drucker’s book, Altered Genes, Twisted Truth, presents this perspective.

Second, the U.S. Department of Agriculture does not allow GMO foods to be labeled “organic,” which the typical consumer understands to mean “natural,” which does not include gene manipulation.

Third, the primary use of genetic modification technology, by far, has been to create food crops that can tolerate RoundUp, a synthetic chemical weed killer that have been found to be carcinogenic. Vast quantities of this chemical are being dumped on agricultural fields.

Fourth, farmers must buy seeds that tolerate weed-killing chemicals annually, rather than saving and planting their own seeds. This raises the operating costs of small farms, and too many farmers in the Far East have committed suicide in economic despair.

Fifth, winds have blown pollen from GMO crops into nearby field of organic crops, contaminating those fields and nevertheless prompting GMO seed producers to claim theft of their private property.

Federal laws that provide the basis for FDA regulations do not address these economic and environmental impacts of GMO-based agribusiness. They focus instead on nutritional content. Recent studies have concluded that certified organic foods are more nutritious than conventionally grown foods (including GMO foods), but more importantly labeling GMOs should raise questions about the unintended fallout of GMO-based agribusiness.

In a perfect world, GMO technology would target good health and good taste, not weeds, and would yield seeds that belong to the world, rather than profiteers. Until then, the consumer’s best choice is to enjoy organic foods.

Progress on GMO Labels

 

Congress continues to battle over food labels, with a recent victory for the public interest.

People who want to know what they’re eating can read Nutrition Fact labels, which the U.S. Food & Drug Administration requires to list the nutritional content of the food product.

In recent years, scientists have developed ways to bypass natural changes in foods by tinkering with their genetic makeup. The results are called genetically modified organisms or GMOs.

The FDA says that GMOs do not differ nutritionally from other foods, and has not required labeling of GMOs. The U.S. Department of Agriculture, however, says that GMOs do not qualify as organic foods.

Still, many consumers—the overwhelming majority, in fact—want to know if fruits and vegetables are GMOs and if food products in grocery stores contain GMOs. Consumers are concerned that GMOs could produce seeds that float into fields of organic foods and change them, or that GMOs have undiscovered ill affects on our health or the environment, or that GMOs enable agribusiness to control the market for seeds. (Historically, farmers would simply save seeds from one year’s crop to plant in the following year.)

Monsanto Corporation and a few other companies that develop GMOs strongly oppose labels that identify GMOs, believing that consumers will interpret such labels as warnings and avoid such foods. Several countries have either banned GMOs or required them to be labeled. In the U.S., some local governments have banned GMOs and several states have tried to pass laws requiring labeling, but industry lobbyists succeeded with intensive campaigns to defeat those initiatives.

One state, Vermont, has approved a GMO labeling law that is to go into effect on July 1st. Some food industry companies opposed Vermont’s law legally, but lost in court. Those opponents have asked Congress to block the states, including Vermont, from requiring GMO labels.

On March 1, 2016, Senator Pat Roberts (R-KS) introduced the National Voluntary Bioengineered Food Labeling Standard (S. 2609) to (a) allow voluntary labeling of GMO foods, (b) prohibit states from requiring GMO labels, and (c) mandate a federal program to promote consumer acceptance of agricultural biotechnology.

Several consumer groups called this legislation the Denying A Right to Know (DARK) Act and urged consumers to ask their state senators to vote it down. These groups want mandatory labeling on the packages of food products, using clear language and not codes, symbols or acronyms. They dismiss industry claims that such labels would increase the cost of foods: two large companies, Campbell and General Mills, soon will begin labeling GMOs without added costs.

The Senate quickly rejected S. 2609 with a margin of eleven votes. Senator Roberts has vowed to sweeten it a little and bring it back.

Meanwhile, a group of six senators introduced Biotechnology Food Labeling Uniformity Act (S. 2621) to establish a requirement for standard labeling of GMO foods. The sponsors include Senator Diane Feinstein (D-CA) and Senator Bernie Sanders (D-VT).

If you wish to avoid GMOs, your best option is to buy organic foods. By federal law, foods labeled as organic cannot contain GMOs.

***

The plant exchanges are springing into action! Several occur each year in the Monterey Bay area. The first one spotted, a monthly occasion, begins Saturday, March 26th (yes, tomorrow) at the Live Oak Grange Hall parking lot, 1900 17th Ave, Santa Cruz. Plant exchanges bring together gardeners who prefer to share their surplus plants with other gardeners who enjoy expanding their gardens without cost. Great tradition!

Propagating Plants

According to meteorologists, the Spring Equinox occurs tomorrow (Saturday), just before midnight, but the first full day of spring will be on the following day (Sunday).

In any event, spring’s arrival inspires many thoughts of gardening opportunities. This column addresses three timely tasks.

Propagating Plants from Cuttings

First, real gardening includes the propagation of plants. One method for getting new plants that is particularly good in the early spring is taking cuttings from existing plants. The timing is good because cutting from the new growth of existing plants can be rooted easily.

Practicing this technique is both frugal and fun, so survey your garden and the gardens of others for plants that you would like to propagate, either to add to your own garden or to gift to other gardeners. If you want more of someone else’s plants, ask permission to take cuttings!

Start by preparing your containers, e.g., small plastic nursery pots, by filling them with planting mix from a garden center, rather than garden soil, which might have bacteria or fungi that could harm young plants.

Using clean clippers, take cuttings of about three inches from the tender green growing tips of plants. The cuttings should be flexible, not woody.

Strip the lower leaves from the cuttings, and insert the stems into damp soil. Place the planted containers where they will be warm but protected from direct sunlight.

Follow up by keeping the cuttings moist. This involves occasional watering and perhaps providing a mini-greenhouse of plastic sheeting to reduce water loss from evaporation. If moisture condenses on this covering, the cuttings could be too moist and vulnerable to fungal problems, so remove the covering for an hour or two to let the excess moisture evaporate.

Your new plants could require several weeks to establish roots, at which time they will develop new leaves. To check their status, tug very gently on the cutting to detect resistance from the new roots.

When you have rooted cuttings, move the plants into larger containers or the garden, and congratulate yourself.

Propagating Plants from Seeds

Planting seeds is also a frugal and fun approach to real gardening. The process is very similar to propagation from cuttings, but it offers a broader range of options and requires more time.

Seeds are available from garden centers. If you want to grow varieties that are not offered by a local garden center, visit Cyndi’s Catalog of Garden Catalogs (www.gardenlist.com/) for many, many options.

Almost all seed packets have basic instructions for growing the particular seeds.

Propagating Plants from Plant Sales

You could get more of the plant you like by just buying them. That approach also works for plants that are new to your garden!

Mark April 9th on your calendar for the combined plant sales of the UC Santa Cruz Arboretum and the California Native Plant Society, Santa Cruz County Chapter. For information, visit the Arboretum’s website (arboretum.ucsc.edu/news-events/events/).

Mark April 23rd & 24th on your calendar for the Spring Show & Sale of the Monterey Bay Area Cactus & Succulent Society. For information, visit the Society’s website (mbsucculent.org).

Spring is here and time to enjoy your garden!

Pruning Daphnes and Salvias

According to meteorologists, the Spring Equinox occurs tomorrow (Saturday), just before midnight, but the first full day of spring will be on the following day (Sunday).

In any event, spring’s arrival inspires many thoughts of gardening opportunities. This column addresses three timely tasks.

Propagating Plants from Cuttings

First, real gardening includes the propagation of plants. One method for getting new plants that is particularly good in the early spring is taking cuttings from existing plants. The timing is good because cutting from the new growth of existing plants can be rooted easily.

Practicing this technique is both frugal and fun, so survey your garden and the gardens of others for plants that you would like to propagate, either to add to your own garden or to gift to other gardeners. If you want more of someone else’s plants, ask permission to take cuttings!

Start by preparing your containers, e.g., small plastic nursery pots, by filling them with planting mix from a garden center, rather than garden soil, which might have bacteria or fungi that could harm young plants.

Using clean clippers, take cuttings of about three inches from the tender green growing tips of plants. The cuttings should be flexible, not woody.

Strip the lower leaves from the cuttings, and insert the stems into damp soil. Place the planted containers where they will be warm but protected from direct sunlight.

Follow up by keeping the cuttings moist. This involves occasional watering and perhaps providing a mini-greenhouse of plastic sheeting to reduce water loss from evaporation. If moisture condenses on this covering, the cuttings could be too moist and vulnerable to fungal problems, so remove the covering for an hour or two to let the excess moisture evaporate.

Your new plants could require several weeks to establish roots, at which time they will develop new leaves. To check their status, tug very gently on the cutting to detect resistance from the new roots.

When you have rooted cuttings, move the plants into larger containers or the garden, and congratulate yourself.

Propagating Plants from Seeds

Planting seeds is also a frugal and fun approach to real gardening. The process is very similar to propagation from cuttings, but it offers a broader range of options and requires more time.

Seeds are available from garden centers. If you want to grow varieties that are not offered by a local garden center, visit Cyndi’s Catalog of Garden Catalogs (www.gardenlist.com/) for many, many options.

Almost all seed packets have basic instructions for growing the particular seeds.

Propagating Plants from Plant Sales

You could get more of the plant you like by just buying them. That approach also works for plants that are new to your garden!

Mark April 9th on your calendar for the combined plant sales of the UC Santa Cruz Arboretum and the California Native Plant Society, Santa Cruz County Chapter. For information, visit the Arboretum’s website (arboretum.ucsc.edu/news-events/events/).

Mark April 23rd & 24th on your calendar for the Spring Show & Sale of the Monterey Bay Area Cactus & Succulent Society. For information, visit the Society’s website (mbsucculent.org).

Spring is here and time to enjoy your garden!

Seasonal Pruning

The vernal equinox is really more significant for meteorologists than it is for gardeners. Some plants respond to changes in day length, of course, but they don’t perform differently merely because days and nights are equal in duration.

Still, the vernal equinox (March 19, 2016) is a useful marker for the change from winter to spring.

As the world experiences climate change, scientists who study the seasons (phenologists) are generating more interesting reports about bud break, flower opening, insect emergence, animal migrations and other seasonal phenomena.

We are already witnessing changes in our gardens: for example, my lilacs are blooming earlier than they have in previous years. Lilacs (Syringa vulgaris) typically require a significant chill during the winter months, but decades ago, Walter Lammerts, working at a southern California nursery now known as Descano Gardens, developed three low-chill lilac hybrids: ‘Lavender Lady’, ‘California Rose’ and ‘Angel White’ (pictured). Gardeners in the Monterey Bay area and similar climates can grow Descanso hybrid lilacs and enjoy their fragrance.

Lilac 'Angel White'

Lilac ‘Angel White’

At the same time, my salvias are fading noticeably, earlier than I usually see.

These two garden favorites have markedly different pruning requirements. The lilacs bloom on new wood, so they should be pruned soon after the blossoms fade, before new buds form. This work should be done before June.

Another important maintenance issue for lilacs manages their strong desire to spread through underground runners. When allowed to roam for a few years, a healthy lilac will form a thicket. This may be desirable, depending on the shrub’s location within the garden, but containment might be appropriate. Accomplish this by the straightforward approach of excavating and cutting off the runner that has created the unwanted new growth.

By contrast, salvias can be cut back to about six inches above the ground in early spring, as new growth appears at the plant’s base. Such renewal pruning cleans away the old growth and stimulates vigorous new growth on these garden standbys. The right time for this work will occur in about one month. It is OK to prune earlier before the new growth is evident, but the ideal timing will shorten the least decorative period for your salvias.

A friend, busy with other priorities, saw the traditional season for rose pruning come and go this year, and now asks if she should prune her roses late, or let them go until next year.

The general rule for roses is to prune during the winter months, when the plants are dormant. Still, the popular repeat-blooming hybrid tea roses should be cut back as blossoms fade during the summer months. According to David Austin Roses, this approach will stimulate blossoming and support maintenance of a desirable rounded shape for the plant.

If a missed winter pruning has allowed a rose to compromise its overall shape, the gardener’s strategy should include summer pruning, cutting back stems after blooms fade with shaping the plant in mind, as well as encouraging new growth.

Pruning can be a challenging task for the gardener because of differences in best practices for individual genera. A good pruning book can help to reduce uncertainty, put the gardener in control and make the process easier and ultimately creative.

Enjoy your garden and keep your pruning shears clean and sharp.

Send pruning questions to Tom Karwin

 

A Not-to-Miss Event

As we enjoy the final days of winter, warmly, we begin thoughts of the arrival of spring and the reemergence of our gardens. With exquisite timing, the annual San Francisco Flower & Garden Show brings the season into focus and offers an unparalleled array of inspiration, information and products to help avid gardeners to launch the year’s gardening activities.

The SF Show began over thirty years ago as a fundraiser for the San Francisco Friends of Recreation and Parks, and soon evolved into a commercial event that features landscape designers, speakers on numerous topics in gardening, and exhibitors of plants and a wide range of garden products.

The Show ranks as one of the nation’s three largest annual events devoted to gardening and landscaping. The others are the Northwest Flower & Garden Show, which was held in mid-February in Seattle, and the Philadelphia Flower Show, which will be held March 5–13. Since 1829, the Philadelphia Horticultural Society has sponsored the Philadelphia Show as a fundraiser.

The world’s most significant competitor to these three garden shows is the Royal Horticultural Society’s Chelsea Flower Show, to be held May 24–28, 2016, at the Royal Botanical Gardens, Kew (near London).

This brief survey of major garden shows indicates that the SF Show amounts to a major event for gardeners of the west coast, and a great and accessible resource for gardeners of the Monterey Bay area.

This year’s SF Show will include 125 free seminars by gardening experts who have been selected as effective speakers. The seminar speakers and schedule is available on the SF Show’s website. The seminars are scheduled in five different stages within the San Mateo Event Center, so your attendance requires a little planning.

The Show also includes over 200 exhibitors in the Plant Market and The Marketplace. If you need any new plants or tools or garden art, you are likely to find them at the SF Show. One of the favorite exhibits is the large display by Succulent Gardens, from near Moss Landing. Early word is that this booth will be larger than ever, in response to enthusiastic collectors of succulent plants.

I will bring a couple mail order catalogs of garden plants and supplies for reference in evaluating prices at the SF Show. The prices are reasonable, I believe, but I always appreciate bargains.

The highlight for many visitors will be the Showcase Gardens, which will include nine full-size garden displays of the talents of landscape designers and craftsmen from northern California. The gardens often dazzle visitors by providing elaborate presentations of beautiful plants, stunning settings and unique concepts. These gardens present thematic designs that incorporate many ideas that can be adapted for your own garden. The designers of course will welcome new clients, and most will also be on hand to answers visitors’ question.

A day at the SF Show is really close by, not expensive, and an exceptional opportunity to bring gardening ideas and riches back home. It should be on your calendar.

If You Go

What: San Francisco Flower & Garden Show

When: March 16–20, 2016

Where: San Mateo Event Center

Info: http://sfgardenshow.com/

Biochar: Ancient Soil Amendment

As we continue to learn about gardening, we are often reminded of nature’s essential role in the process, and, by extension, the wisdom demonstrated by historical gardeners as they worked in concert with nature.

We have countless examples of the benefits of “gardening with nature,” and ample evidence of the short-sightedness of technology-based agribusiness.

”Technology” as used here encompasses monocropping, animal feedlots and synthetic fertilizers and pesticides, as well as more constructive activities such as the use of drone aircraft to monitor crops. Should watch out drone jammers, though.

One fascinating historical instance of natural gardening is biochar. The briefest definition of biochar is organic matter that has been heated to high temperatures with limited oxygen to produce charcoal. This process (pyrolysis) also produces gasses that can be burned to produce electricity.

Screen Shot 2016-02-28 at 12.08.40 PM

Biochar is very similar to charcoal, which is made principally from wood, and used in backyard barbecues and a variety of industrial processes. Biochar, by contrast, is made from all kinds of organic waste, particularly garden or agricultural waste, and is used as a soil amendment, adding carbon to the soil.

 

Note: The biochar photo is from a good article by Jeff Cox in Rodale’s Organic Life.

Biochar apparently has been produced and used for thousands of years by early gardeners in Brazil’s Amazon River Basin to improve their rather poor soils. In 1870, an American geologist and explorer discovered and reported areas of dark and highly fertile soil. Researchers puzzled over the origin of this unusual soil, called “terra preta” but recognized that it has strong benefits for agriculture.

During the past twenty years or so, scientists have attributed several valuable properties to biochar, beyond improving crop yields. The additional benefits include increasing water-holding capacity of soil, reducing the need for chemical fertilizers, reducing natural emissions of greenhouse gasses (nitrous oxide and methane) from agricultural soils, increasing soil microbial life, resulting in carbon sequestration, avoiding the natural decomposition of agricultural and forestry waste and thereby decreasing carbon dioxide emissions.

These benefits are stimulating great enthusiasm for uses of biochar in both gardening and agriculture. For example, scientist James Lovelock, author of The Gaia Theory, has written, “There is an outside chance that one procedure could really turn back the clock on Global warming and that is burying carbon. All you have to do is get every farmer everywhere to make a profit by turning all his agricultural waste into char and burying it.”

This success story has only an outside chance because it assumes universal participation by the world’s farmers, but does reflect the genuine value of biochar.

Still, individual gardeners could help to reverse global warming by using biochar. This material is available commercially, but it’s costly. A quick survey of sources on the Internet shows a typical price around $30 per cubic foot, enough to amend a garden bed of twenty-four square feet.

A gardener could produce biochar with little or no expense. Here are brief directions from Barbara Pleasant, Mother Earth News (2009): “Pile up woody debris in a shallow pit in a garden bed; burn the brush until the smoke thins; damp down the fire with a one-inch soil covering; let the brush smolder until it is charred; put the fire out.”

For more on this topic, visit the International Biochar Initiative.

Biochar could increase dramatically the fertility of your soil, and help you to rival the successes of ancient gardeners of the Amazon Basin.

More

A reader’s query and my reply.

Q: I read your article in Friday’s Sentinel about biochar. I am wondering if I can put used, regular, charcoal from the grill in the garden. There is always some left over. Can I break it up and put it in my garden?

It seems like I read somewhere years ago I could, but I can’t remember.

A: By “used charcoal” do you mean ashes?

I have attached a short article that is about Colorado’s soil, but California soil also tends to be alkaline, so the article has relevance in our area as well.

Charcoal is Not a Good Soil Amendment in Colorado

The bottom line is that charcoal ash, which is alkaline, would have some value when added to very acidic soil, i.e., low pH, but doesn’t add any fertility to the soil.

On the other hand, unburned, or partially burned charcoal briquettes (made from wood) could be useful as a soil amendment, although they have less nutrient value than biochar, which is made from a range of vegetative materials.

Charcoal briquettes usually contain cornstarch as a binder, and might include coal, lime and other ingredients, none of which would be harmful in the garden. Soften them in water to break them down, then dry the result to mix into fertilizers or directly into the soil.

I hope this is helpful

Another reader’s comment: 

Dylan Gillis

Fine article, though it sort of glosses over the fact that biochar itself is 99% carbon that stays in the soil for hundreds if not thousands of years. While compost only costs $3 or more per cubic foot (depending on quality, volume you buy and packaging/marketing variables) it needs to be replaced every year, forever, to result in similar levels of carbon sequestration and fertility. Of course the best is to add biochar, once to satisfactory levels, and then amend with compost for the nutrients and energy feeding the soil life, every year. In this approach you would use less compost to get the same or better results and your carbon sequestration would be more or less permanent!

Drama for the Landscape

 

One of the most spectacular plants from South Africa, in exuberant bloom at this time of the year, is Aloe arborescens. It can be seen throughout the Monterey Bay area, occasionally having spread into impressively large clusters of plants.

The specific name means “tree-like,” because the plant can grow to close to ten feet high. Structurally, the plant consists of several branches, each of which ends in a rosette of leaves edged with small spikes. Each rosette can generate several flower stalks that produce cylindrical inflorescences (racemes). The individual flowers, typically a bright orange-red, are tubular and attractive to hummingbirds. The clusters of flowers resemble the flame of a torch, leading to the plant’s common name: Torch Aloe.

DSCF0022 DSCF0023 DSCF0024 DSCF0025

Several years ago, I planted my first specimen of this succulent plant, a single rosette, in a well-drained bed. It grew rapidly and extended runners (stolons) that produced new plants, ready to take over the bed. Not knowing its full growth potential, but realizing that it was too productive for that small bed, I shovel-pruned it, replanted three rosettes in front of a nearby compost bin, and placed most of the rest in the bin.

The replanted rosettes grew readily into a dramatic presence in my garden, and also shielded the compost bin from view.

A. arborescens is related to A. vera, a smaller, more familiar South African native that is popular for its ornamental, cosmetic and medicinal values: its juices reportedly have rejuvenating, healing, or soothing properties.

The Torch Aloe also reportedly has value in promoting good health. Some people advocate a drink made from the pureed whole raw A. arborescens leaf, unheated raw honey and 1% certified organic alcohol. This drink is claimed to support immunity from a range of diseases and provide general cleansing for the whole body. It is reported to be “bitter, but unctuous and savoury as well, thanks to the honey.”

I have plenty of leaves but have not tried the drink. This is not a testimonial.

A. arborescens is one of about 500 species of the genus Aloe, which includes natives of South Africa, tropical Africa, Madagascar, Jordan, the Arabian Peninsula and some islands in the Indian Ocean. Many grow well in the summer-dry climate of the Monterey Bay area. Most species, unlike A. arborescens, are stemless: the rosettes grow directly on the ground.

A smaller, yellow-flowered variant, called Golden Torch Aloe (A. arborescens lutea), can be found in limited numbers.

Another yellow-flowered form, Yellow Aloe, was discovered in a private garden in Santa Barbara. This plant might be a variant of A. arborescens, a hybrid with another species, or an entirely different species: A. mutabilis, which has red flower buds that mature into yellow.

Aloe arborescens can be an attractive and interesting addition to a landscape that has sufficient space.