Gardening to Save the Planet

We are learning about humanity’s many impacts on the near and distant future of our planet. Some people are in denial about these impacts, while others are concerned and ready to do whatever we can to ensure that our Earth will support future generations.

To support and encourage such positive action, leading botanist Peter Raven will visit the UCSC Arboretum next week to meet with UCSC faculty and staff, and present a public talk, “Saving Plants, Saving Ourselves.” Raven will present an informed update on the increasing threats to Earth’s environment, and emphasize the special role of public gardens in conserving plants that could be lost through habitat loss and climate change.

Peter Raven has a long friendship with the UCSC Arboretum, and a national reputation as a conservationist and advocate of global biodiversity: Time magazine hailed him as a Hero of the Planet. His visit to the Monterey Bay area inspires us to reflect on the home gardener’s unique role in saving the planet.

Here are ten everyday practices that gardeners can apply to help sustain the environment and protect plant diversity.

  • Irrigate your garden wisely, using drip technology to deliver water only where needed, and mulch (organic or inorganic) to minimize evaporation and weed growth.
  • Recycle household water into the garden, using plant-friendly soaps and detergents.
  • Prune your acquisitions of consumer goods that bury our landfills and clutter our environment…and that you really don’t need.
  • Propagate plants that Nature’s pollinators (bees and other insects, bats and birds) love and need to survive. Clusters of flowering plants will enrich your landscape.
  • Conserve biodiversity by protecting endangered species and including rare and threatened California native plants in your landscape. (Visit the California Native Plant Society’s website, www.rareplants.cnps.org/ for info.)
  • Nourish your plants with organic fertilizers, and discontinue uses of artificial chemicals
  • Control plant-eating insects with insect predators and organic insecticides. Use physical barriers and non-toxic deterrents to control other plant-eaters, e.g., snails, gophers and deer,
  • Select plants that are native to California or other summer-dry climates, to enable their healthy growth, support wildlife and ease your gardening workload.
  • Compost the “carbon-rich” fantasies of climate change deniers with the “nitrogen-rich” facts of the world’s scientists to promote wise stewardship of the environment. (Alto, keep all biomass on the property by composting green garden waste!)
  • Cultivate these good practices among your friends and neighbors.

The UCSC Arboretum employs these practices regularly, and assigns high priority to its work in plant conservation.

pt sur Austin and Tim

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This photo shows UCSC student Austin Robey and Arboretum volunteer Tim Forsell as they replanted endangered California native manzanita shrubs on a steep slope near the Point Sur State Historic Park and Lighthouse. The Arboretum’s Brett Hall coordinated the conservation project.

Your practices in your own garden also could help to save the planet. A good start would be to attend Peter Raven’s talk..

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Registrations for the Peter Raven talk sold out quickly. To receive timely announcements of future events at the Arboretum, visit arboretum.ucsc.edu/get-involved/.

If you would like to sponsor an educational event at the UC Santa Cruz Arboretum, contact Jennifer Macotto, 831-427-2998 or jmacotto@ucsc.edu.

For information on how you could help save a rare species: visit arboretum.ucsc.edu/education/plant-sponsorship/.

Low-Maintenance Garden Themes

Designing a garden bed around a theme yields practical and aesthetic benefits.

The aesthetic benefit of thematic garden design rests on the relationships among the plants: they are linked by being members of the class defined by the theme. In that respect, a thematic group is more coherent, aesthetically, than the ever-popular “grab-bag” approach to plant selection.

The practical benefit is a plan for selecting plants from the hundreds of thousands of available varieties. Once the gardener has chosen a theme, he or she has reduced the universe of possible plants to consider. This one action narrows the selection task and supports close evaluation of options.

A garden design theme is simply a concept to which plants relate. This definition embraces a very wide range of possible themes, which could be a single color or combination of blossom colors; a plant genus, e.g., rose, iris, daffodil; size, e.g., miniatures; bee-friendly, etc.

For today’s topic, consider a progression of four themes for low-maintenance gardening.

Theme #1: Zone-appropriate Plants. Every gardener should know the U.S. Department of Agriculture’s Plant Hardiness Zone in which his or her garden exists. The Monterey Bay area is in USDA Zone 9b, where minimum temperatures are in the 25–30 degree range; plants marked for Zone 9 should survive cold spells in that range. A great many plants are that hardy, so this theme excludes only plants that are vulnerable to cold and therefore high-maintenance. Nurseries also use UCDA zones to indicate the preferred zone for given plants. Plants that are rated for Zones 10 or 11 usually will thrive best in very warm climates, not in Zone 9.

Theme #2: Mediterranean Climate Plants. These are plants that have evolved to grow well in the world’s areas that have dry summers and moderate winters. These areas (again) are native to the central coast of California, the central coast of Chile, the southwestern coast of Australia, South Africa and the Mediterranean basin. A large number of plants are suitable for this theme, but this category still is significantly smaller that Theme #1.

Theme #3: California Native Plants. This theme is within Theme #2, of course, but it stands apart from the others because includes plants that are both suitable for the Mediterranean climate and the soils and fauna of this state. Soil chemistry and symbiotic relationships with birds, mammals, insects and microbial life contribute significantly to the growth of plants, and, ultimately, the success of the gardener.

Theme #4: Native Plant Communities. A great variety of plants are native to California, and many have evolved to grow best in specific environments within the state, and in communities with specific other plants. An oak woodland plant community is certainly different from one that occurs naturally on coastal bluffs and cliffs. For the ultimate in low-maintenance gardening, adopt a thematic design for a California native plant community that would be appropriate for your garden setting.

Consider a thematic design for each garden bed or each large area of your garden. Plant selection will transform a random process to a purposeful activity.

Books for Thematic Designs

Zone-appropriate Plants
The New Western Garden Book (Sunset, 2012)

Mediterranean Plants
Plant Life in the World’s Mediterranean Climates (Dalman & Ornduff, 1998)

California Native Plants
California Native Plants for the Garden (Bornstein, Fross & O’Brien, 2005)

Native Plant Communities
Designing California Native Gardens: The Plant Community Approach to Artful, Ecological Gardens (Keator, Middlebrook & Faber, 2007)

 

Spring is Here

This year’s puzzling weather has produced a few days cold enough to promote dormancy in plants that don’t need a real winter chill, and nowhere near enough rain. We still hope late rains will replenish aquifers and reservoirs, but there’s little promise in the forecasts.

The arrival of spring does not cause abrupt change in our gardens, but it does bring warm weather that takes plants out of dormancy and stimulates new growth. Plants need moisture at this time but water restrictions demand reduction of our water usage. The middle ground for gardeners involves watering plants efficiently and only when they show need by wilting a little. This means drip irrigation if you have it, or moving a hose or watering can from plant to plant. Store your wasteful wide-area sprinkler!

If you have been preparing for drought conditions, you have emphasized summer–dry plants, a category that includes California native plants and other Mediterranean climate plants.

This is not the best year to add summer-dry plants, however: newly installed herbaceous or woody plants need regular watering for two years to establish roots.

A more appropriate strategic response to this drought is to add succulent plants, which have developed ways to minimize transpiration and maximize water retention in their leaves, stems or roots.

When added to a garden or moved within a garden, succulent plants come with their own supply of moisture, and need only minimal watering to settle their roots. They are quite resilient, but of course will need some water in time.

Succulents are far from compromises from an aesthetic perspective: they offer a range of blossom colors and foliage textures as well as low maintenance and drought tolerance. They have in fact become desirable specimens in garden beds or containers, even before our current weather concerns.

Happily, a major sale of succulent plants is less than one month away. The Monterey Bay Area Cactus and Succulent Society will hold its annual, free-admission Spring Show & Sale from 9:00 to 5:00 on April 19th and 20th in the San Juan Batista Community Hall, 10 San Jose Street, not far from the Old San Juan Batista Mission.

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The Society’s show will include members’ selected cacti and succulents, demonstrating plants that are very well grown and shown, and that display an amazing range of shapes, sizes and colors. The sale includes a great selection of mostly small plants grown by members or commercial growers, with reasonable prices. Society members also will be available to offer advice and answer questions.

Respond to this drought creatively: use this occasion to start or expand your collection of succulent plants.

More

If you are a beginning gardener of succulent plants, a helpful book is Debra Lee Baldwin’s newest book, Succulents Simplified. Her earlier books, Designing with Succulents and Succulent Container Gardens, are a more advanced, but still accessible for casual gardeners.

succulent books

Visit Debra Lee Baldwin’s website for inspiring photos and practical information.

California Native Roses

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.
    Rosa_californica_California_Wild_RoseAs 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.

More

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.

0CCARosehips copy