Building a garden bed - Santa Cruz Sentinel

ON GARDENING

Building a garden bed

Rock Phacelia (Phacelia californica) This plant is native to coastal northern California and Oregon, where it grows in chaparral, woodland and coastal bluffs and grassland. It grows decumbent or erect, its branching stems reaching 90 centimeters long. It is roughly hairy in texture. The leaves are up to 20 centimeters long, and the lower ones are divided into several leaflets. The dense, hairy flower cluster is a one-sided curving or coiling cyme of many bell-shaped flowers. Each white or pale blue to lavender flower is under a centimeter wide. It is a food source for the Mission blue butterfly, an endangered species endemic to San Francisco. PHOTO COURTESY OF JOHN RUSK VIA WIKIMEDIA COMMONS

Hooker’s Evening Primrose (Oenothera elata ssp. Hookeri). This member of the Evening Primrose plant family (Onagraceae) grows along the coast between San Francisco and San Diego and northern Baja. It is fast-growing and moderately long-lived. Its form may be either upright or sprawling. In an upright form, it grows during the summer to 5 feet tall, with yellow and striking flowers. It spreads by prolific seed production, making it attractive to many seed-eating birds. PHOTO COURTESY OF STICKPEN VIA WIKIMEDIA COMMONS

Compacta Seaside Woolly Sunflower (Eriophyllum staechadifolium ‘Compacta’) This not widely available plant grows best in sandy, coarse-grained, or other fast-draining soil. Prefers sun in coastal sites and partial shade in inland sites. It grows to 2-by-2 feet. PHOTO COURTESY OF DOCENTJOYCE VIA WIKIMEDIA COMMONS

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In this column, we continue the ongoing project of developing a butterfly garden bed based on locally native California plants.

This garden became available when we removed a large, attractive but invasive shrub (Cotoneaster lacteus) that had dominated this 270-square-foot bed. We left in place a mature Lewis’ mock-orange (Philadelphus lewisii) to anchor the bed.

The available space was about 250 square feet. A substantial number of new plants would be needed to fill the bed, particularly given our intention to plant closely to discourage weed growth.

This “green mulch” approach has been refined as “matrix gardening,” popularized by Dutch garden designer Piet Oudolf. As described in our May 23 column, “Matrix planting involves three layers of plants: groundcovers, smaller and larger seasonal perennials. It does not include annual plants but could include architectural perennials (shrubs, and trees), if that works in your garden.”

Our columns on matrix gardening are accessible from the Sentinel archive (browse to santacruzsentinel.com and search for “Karwin”).

To install plants closely in a 250-square-foot bed, assuming the average size of mature plants are 3-by-3 feet, we would need about 28 plants.

We worked with two lists to select plants. The first was California Native Plant Society’s Calscape database (calscape.org) list based on my search for shrubs and perennials that (a) are native to Santa Cruz County, (b) are up to 6 feet tall and (c) attract butterflies. This search yielded 102 plants.

The second plant list was the Fall Sale Plant List posted online by the Santa Cruz Chapter of the California Native Plant Society (cruzcnps.org). The Oct. 12 sale’s available list included 131 plants. My gardener and I marked the plants that occurred on both lists and arrived early at the sale.

We shopped efficiently and managed to collect 18 plants that met our criteria. When available at the sale, we included three specimens of each plant to fill space and develop pleasing groupings. We’ll need another 10 plants to complete the green mulch approach to this bed.

We also acquired 15 California native plants for other parts of the garden.

Here are the plants we gained for the butterfly garden.

• Achillea millefolium ‘Island Pink’ — Yarrow — 2

• Diplacus aurantiacus — Pinnacles Bush — Monkeyflower — 2

• Eriogonum fasciculatum var. foliolosum — California Buckwheat — 1

• Eriogonum grande var. rubescens — Red Buckwheat — 1

• Eriophyllum staechadifolium ‘Compacta’ — Seaside Woolly Sunflower — 3

• Grindelia stricta var. platyphylla — Coastal Gumplant — 3

• Oenothera elata ssp. hookeri — Hooker’s Evening Primrose — 3

• Phacelia californica — Phacelia — 3Today’s photo gallery includes images of some of these plants that we have not previously posted. These images were downloaded from Wikimedia Commons (commons.wikimedia.org). The captions are edited from Calscape.org descriptions.

The plants gathered to date for this bed present various blossom colors and plant sizes and should present a satisfying appearance for gardeners and butterflies. While we have installed plants appropriately according to size, we have not coordinated blossom colors or bloom periods. Such detailed garden design, while a fine idea, is accomplished easier on paper than in the real world.

We will search for additional perennials that meet our criteria. In the spring, we anticipate the preliminary crop of annuals will re-seed and further fill the space. It should be an evolving landscape.

Enjoy your garden.

Tom Karwin is a past president of Friends of the UC Santa Cruz Arboretum and the Monterey Bay Iris Society, a past president and Lifetime Member of the Monterey Bay Area Cactus & Succulent Society, and a Lifetime UC Master Gardener (Certified 1999—2009). He is now a board member of the Santa Cruz Hostel Society, and active with the Pacific Horticultural Society. To view photos from his garden, https://www.facebook.com/ongardeningcom-566511 763375123/ . For garden coaching info and an archive of On Gardening columns, visit ongardening.com for earlier columns or visit www.santacruzsentinel.com/ and search for “Karwin” for more recent columns. Email comments or questions to gardening@karwin.com.