Time to Plant Your Garden

Over the next few weeks, as we move into autumn, it is time to think about installing new plants in our gardens, and moving plants that should be in better places.

Installing or moving plants makes sense during this time of the year for two reasons. First, many plants that are good choices for Monterey Bay area gardens are entering into a dormant period, during which they can be moved with minimal trauma from one garden location to another, or from a nursery pot to a larger container or into the ground.

The second rationale for installing or moving plants now is that our familiar rainy season, beginning usually mid-October, will irrigate them during dormancy. The gentle rains of fall and winter have been a welcome gift to gardeners, who can attend to other tasks as plants develop their roots and generate new growth for the spring, as temperatures warm.

We still do not know if we will have a normal rainy season this year. Recent reports from International Research Institute for Climate and Society and the Climate Prediction Center, both trackers of the El Nino/Southern Oscillation, indicate a relatively small impact on our fall and winter weather, around 60 to 65% of the historical norm. In other words, we should expect rain, but not as much as we usually enjoy.

That forecast is more vague than gardeners would like, but now is still the time to plant. The worst-case scenario is that watering by hand or drip irrigation might be needed to keep newly installed plants adequately hydrated.

Gardeners might be inspired to bring new plants to their gardens in the spring, when garden centers are displaying plants in bloom. There are real advantages of planting in the spring: bedding plants are available in abundance, blossom colors are evident, and the weather welcomes outdoor projects. One downside of this schedule, however, is that customers pay for nurseries to care for the plants during their early growth. Also, plants that have been boosted into bloom with synthetic fertilizers often under-perform once they have been moved into typical garden soil.

When you bring new plants into your garden this autumn, choose plants that are drought tolerant and well suited for the local climate and growing conditions. Such plants are most likely to succeed under drought conditions with the only basic care by the gardener.

Remember: even drought-tolerant plants need water, just not as much and not as often.

Good opportunities soon will be available to find such suitable plants:

  • Succulent Extravaganza, September 26 & 27 (today and tomorrow); 2133 Elkhorn Road, Castroville. Info: sgplants.com, 831-632-0482.
  • Fall Plant Sale, UC Berkeley Botanical Garden, September 28; 200 Centennial Drive, Berkeley. Info: botanicalgarden.berkeley.edu, 510-643-2755.
  • Fall Plant Sale, UC Santa Cruz Arboretum & California Native Plant Society, October 11; High Street at Western Drive, Santa Cruz. Info: arboretum.ucsc.edu.
  • Fall Show & Sale, Monterey Bay Area Cactus & Succulent Society, October 18 & 19, 10 San Jose Street, San Juan Batista. Info: www.facebook.com/MonteryBayAreaCactusAndSucculentSociety

Gardening success depends on the selection of plants that are appropriate for specific locations and growing conditions. You might change where you garden, but external forces could change your garden’s growing conditions. Plan ahead!

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/.

Are Your Plants Dying?

Of course they are!

All living plants age and eventually die. The only exceptions are plants that are man-made from plastic or other materials.

The aging process, called senescence, begins after the plant achieves reproductive maturity and ends when the plants dies.

Senescence is an inevitable component of plant cultivation, so gardeners should recognize and understand the process, and appreciate its benefits.

There are several kinds of senescence.

Whole Plant Senescence occurs when the entire plant dies after seed production. This occurs with annual and biennial plants, and also with monocarpic plants, e.g., the Century Plant (Agave Americana), which can grow for several years before producing seeds. The benefits of this kind of senescence include genetic diversity (each seed cycle combines genes from different plants) and increased survivability (the plant uses it resources for producing seeds, rather overwintering).

Sequential Senescence is typical of perennial plants, in which the leaves age and die, but the main shoots continue to produce new buds and leaves. This is characteristic of woody perennials, i.e., shrubs and trees, which build their roots and aboveground structure year after year, and thus increase their abilities to produce seeds and compete with other plants. A good example is the apple tree, and many other fruit-bearing trees. The tradeoff is less genetic diversity for the tree itself, although achieve genetic diversity through its fruits. Still, the tree is more vulnerable to rapid environmental changes and attacks of insects or diseases.

Shoot Senescence occurs with certain plants that die to the ground after flowering and fruiting, but retain their belowground stems and roots, which produce new shoots in the following season. Examples of such plants include the banana and the gladiola, as well as virtually all other bulbous plants.

Synchronous Senescence is controlled by environmental factors. In this process, temperate deciduous trees drop their leaves in response to seasonal changes in the temperature, typically as in late autumn. At this period, the leaves’ green chlorophyll decomposes, revealing the leaves’ carotenes, which may be yellow, orange or orange-red. In California, we look for fall color in elms, many Japanese maples, Chinese Pistach, Liquidamber, Bradford pear, flowing dogwood and others. The living fossil Maidenhair Tree (Ginkgo biloba) is noteworthy because in the fall its leaves change from green to saffron yellow, and then all fall not quite simultaneously, but within a short period.

Fall Leaf Senescence

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Woody plants also will self-prune during the growing season: leafy shoots that are not growing well die off, and the plant re-directs its nutrients to other shoots. I see this impressive self-regulatory function mostly with interior shoots that may lack sufficient exposure to sunlight. Similar, but less visible self-pruning also occurs with roots.

Gardeners need to be alert to dieback that can occur in addition to the natural processes of senescence. Such diebacks could result from controllable environmental impacts, from temperature, wind or sun exposure, insects, diseases, or herbivores; water shortages; or nutritional deficiencies. The first step in correcting a problem is analyzing its cause.