Dry Gardening in Walnut Creek

Judy Addler's dry garden in Walnut Creek is irrigated only with rain fall. The garden is located on an undeveloped hillside with full sun close to a nature preserve. I was especially interested to learn how Judy developed the garden oasis with nature in mind.

Moody view of the dry garden as clouds pass overhead

Compost is key. She receives loads of wood chips from landscapers and arborists who are eager to dispose of it, and spreads it liberally over the site. The result is rich dark soil that soaks up water that falls on or drains through it. Paths of wood chips help protect the soil structure as students and visitors walk over the land.

Working with nature to improve the soil with compost, and capture draining water in sinks

In additional, she purposefully makes piles of sticks and branches to compost. They serve as habitat and protection for small wildlife, and protect seedling plants that need protection from deer and larger animals.

In one area of the hill, she uses logs and sticks to slow down water drainage. This creates a sink, and gives water runoff a chance to seep into the soil.

These are all practices that you can observe in nature, and a great idea to implement in the home garden where possible.

Native Plant Propagation Workshop

I recently attended a native plant propagation workshop sponsored by Bring Back the Natives. After last year's focus on pollination and plant propagation, the workshop sounded like a good next step. Judy Addler teaches "California native plant propagation: How to create native plants from seeds, cuttings, and divisions". Judy is a passionate sustainable gardener and educator, with an experimental garden in Walnut Creek. She loves to teach kids and adults about native plants, biodiversity, ecology, and sustainable gardening.

Judy prepping for the workshop

Native seeds used for plant propagation

In the outdoor workshop, we learned about seed propagation, seed collection, and the importance of seed saving. We toured the dry garden that Judy has developed over the last 20 years, the teaching garden close to the nearby elementary school, and her personal test garden with its fruit trees, chickens, and water harvesting.

Dividing bunch grass for propagation

Native elderberry started from woody cuttings

Scions for edible walnuts may be grafted on to hardy native root stock

Judy demonstrated her approach to plant propagation – collecting seeds for later planting or just tossing them nearby the parent; dividing bunch grass and sticking the divisions in the ground; pinching off soft and hardwood cuttings for replanting; describing how English walnut scions were grafted onto native walnut root stock; layering native honeysuckle and grape vines; and sticking woody stems in the ground to sprout roots from the nodes.

Milkweed, favored by migrating Monarch butterflies, propagate through underground runners

Coyote bush (foreground) are dioecious so propagate with this in mind

Layering was used to start the native honeysuckle and grape vines on the fence

The whole-time Judy layers in information about observing the land, taking clues from nature, and using native plants to create a wildlife habitat. Her approach is fearless and experimental (not a root hormone or coddled plant in sight). We left with our collection bags full and ready to try it for ourselves. I highly recommend this workshop, and any other offered by Bring Back the Natives.

Ready to propagate plants collected in Walnut Creek

Roaming in San Ramon

In January, I mentioned that my work office was moving to Bishop Ranch in San Ramon, after many years in Dublin, California (see Looking Ahead to 2017). The company had been in the Dublin office for 15 years, and during that time the business and community grew together. We were situated close to Camp Parks Training ground and some undeveloped land, as well as residential and shopping areas. Many of us enjoyed daily walks in the area, and always found something new to see. I reported on street trees, turkeys, working goats, and many other topics during my time there.

Roaming in San Ramon

Fast forward a couple of months to find us moved and settled into our new location in San Ramon. The facility is beautiful – everything is new, and fresh, and designed with the modern work force in mind. The conference rooms are named after regional and national parks (I sit close to Joshua Tree and Glacier Bay). The Mount Diablo conference room has a spectacular view of its name sake. The grounds are also beautiful – built on a grand scale, landscaped with the environment in mind, and irrigated with potable water as Dublin was (see Gray Water in Dublin). Flowering trees line the paths, so spring should be spectacular.

Even with the winter rains, many of us are out enjoying our daily walks and exploring our new digs. Shopping, a library, and the San Ramon pool are nearby. Walking paths, workout stations, and proximity to a lake bring nature to our working lives. I’m looking forward to exploring the Iron Horse Regional Trail next, with access a block away. The trail is built on an old Southern Pacific Railroad bed that runs from Pleasanton to Concord. Change can be stressful, but it can also be rejuvenating, and often results in new possibilities and opportunities!

Designing with Color

In Color Theory, we learned a little bit about how light and color works, and learned some basic terminology to help us talk about color. Color wheels can help with identifying primary and secondary colors, and understanding how colors relate. Now I’d like to use Penelope Hobhouse’s book, Color in Your Garden, to list some of her observations about how to use color in the garden.

• Colors are not seen in isolation – each is perceived in relation to neighboring colors.
• Colors change constantly in the garden. Color is effected by light and shade, viewing distance (close and far), and weather and environmental factors. Surface texture can make colors appear dark and bold to light and matt.
• Bright sunlight appears yellow, so in midday sun red and orange flowers may appear dull. In a temperate climate with overcast skies, muted greens may appear to glow and white flowers shine, while bright colors look garish.
• The eye sees color before shape, and sees red, yellow, blue and green most distinctly. The eye’s natural focus coincides best with green or greenish yellow in sunlight, making green feel restful.
• Red (the longest wavelength) requires you to refocus your lens, as does blue and violet (the shortest wavelength). Red objects appear to advance to foreshorten distance, and blue and violet objects seem to recede into the distance.

Designing with color (color wheel painted by Jason Quisenberry)

• Distant colors in the garden tend to fade due to the atmosphere’s scattering of light. Bright red and orange objects in the foreground tend to retain their defined form, even when you move away from them, while dark toned blues and violets blend and blur as you move away from them.
• The eye registers hue and decodes color by its properties including lightness and darkness, dullness and brightness. The eye exaggerates differences between adjacent colors, and is influenced by emotion, personal and cultural bias.
• The eye is subject to several optical phenomena. (1) Successive contrast – stare at a vivid color, then at a white paper. The after-image is the color's opposite on the color wheel (for example, the after-image of blue is orange). (2) Simultaneous contrast – two colors side by side are simultaneously affected by the after-image of the other, and each color appears tinged (for example, juxtaposed blue and yellow objects may appear to have a tinge of  violet).
• Colors retain their truest colors next to white. Gray reflects all light rays but less strongly than white. Gray foliage appears lighter or darker as neighboring colors become darker or lighter, while gray leaves accentuate the purity and brightness of adjacent flowers. Next to gray, pure hues glow vividly, while pale pastel tints brighten. Gray leaves become tinged with the haze of nearby complementary colors.

This is just a summary of some of Hobhouse’s observations, and not hard and fast rules. Color preference is very subjective and personal (part of what Hobhouse calls “the mystery of color”). But being aware of these observations and ideas can help the gardener design with color, in a similar way that the artist designs a work of art.

Color Theory

This year we’re learning more about color, and how to incorporate color in our garden designs. We’re using Penelope Hobhouse’s book, Color in Your Garden, as a guide on our quest. As always, we need some terminology to helps us communicate, and some basic information to help us understand. Don’t worry – I’m providing an overly simplistic treatment of the subject (feel free to seek other sources if you want to learn more about the art and science of color theory)!

Color wheel (painted by Jason Quisenberry)

Since we are “painting with light” in the garden, our color theory focuses on light rather than pigment. Some useful concepts:

• A white surface reflects all light rays; a black surface absorbs all light rays; and a gray surface absorbs and reflects light rays equally.
• Light transmits color in different wavelengths. Light transmits blue in short wavelengths, green and yellow in middle wavelengths, and red in long wavelengths.
• The blue, yellow, and red cones of the human eye respond to the wavelengths, and color is perceived in the brain. The wavelengths overlap to transmit many shades of light, and the brain can perceive many shades of color.

A color wheel depicts the primary colors (blue, yellow, and red), and secondary colors (green, orange, and purple), and provides a language to describe the colors. Some useful terms borrowed from the art world:

• A hue is pure color with no white, black or gray –  primary colors are hues.
• A value is the color’s luminosity – the difference between lightness and darkness.
• Color values indicate a color’s tint (graded toward white), or shade (graded toward black).
• Intensity is a color’s range from dull to bright color.

We will try to use these terms and concepts as we explore the topic of color in the garden.

Color in the Garden

Color in Your Garden, by Penelope Hobhouse, has inspired me to look deeper into the realm of color this year. Here in the San Francisco Bay Area, with its dry seasons and ongoing droughts, our base color is often brown. My own garden is typically shades of green and brown, punctuated with bursts of color throughout the year. Colors range from blues (Muscari, Bluebells, Agapanthus, and Purple gromwell), to white (Magnolia, Azalea, Monkey Flower, and Camelia), to pink and purple (more Azaleas and Camellias, Rhododendron, and Tulip Flower), to red (Toyon berries, Liquid Amber and Japanese Maple leaves, and the occasional cherry tomato).

Gardening Color Wheel
Source: Merritt College Landscape Horticulture Forum 

Hobhouse compares the gardener and the painter—both use shape and structure to form the base composition, and then paint with color (pigment for the artist, and light for the gardener) to complete the work. The painter is typically capturing a static point of view, while the gardener must consider the viewer who moves through the garden. The gardener must also consider the garden’s aspect, soil conditions, water source; the plants that are suitable for the garden site; and the seasonal and lifecycle changes of each plant. When designing the garden, flower color is a relatively small thing to consider!

Sounds daunting, but Hobhouse will walk us through the process – first presenting color theory in an understandable way, and then developing a palette of plants by color group. In addition, we will use the information to develop a palette of plants that is tailored for the San Francisco Bay Area. As we visit parks of the East Bay watershed, we’ll be on the lookout for native plants in each of the color groups, using Wildflowers of the East Bay Regional Park District as a guide (photos by Wilde Legard, Botanist of East Bay Regional Park District, 2007).