JARS v44n4 - Gardening on the San Francisco Peninsula

Gardening on the San Francisco Peninsula
Martha Brockenbrough
Stanford, California

It's not only the grass that is greener on Noel and Ernie Kolak's side of Portola Valley, California. The species dominated collection of rhododendrons and carefully selected companion plants make their garden more colorful than anything around.
But it wasn't always that way. When they moved into their home seventeen years ago, the landscape was bare except for an apple orchard in the front of the house and some large redwoods and eucalyptus at the rear. They removed all but one apple tree and planted deciduous oaks, flowering cherries and Himalayan pines on raised mounds to accommodate future raised beds.
Ernie and Noel were especially careful in deciding how these trees were arranged, as their placement would ultimately determine the shape of the garden. The trees, now rather large, cut through the front part of the garden in a graceful "S."
Onlookers were skeptical when the Kolaks started planting trees on "what looked like little volcanoes," according to Noel. "And then when they heard we were going to plant rhododendrons where fruit trees had formerly grown, people thought we were nuts."
Yet, those who are branded as lunatics often prove to be the visionaries. The trees have flourished, and now Ernie must prune or even remove them to admit more sunlight. In addition to planting trees in those early days, Noel and Ernie carefully built up the soil to provide the proper drainage for the eventual planting of the rhododendrons that were accumulating at an alarming rate in their lath house. Over a period of years they brought up sand from the creek that borders their property, as well as had many 40-yard truck-loads of wood chips and coarsely-shredded redwood bark delivered.
"You get a truckload like that," Ernie assures, "and it looks like a small house." Together, they moved it with wheelbarrows. "It literally took years to build up that soil," admits Ernie.
Now, they have a planting medium from the perfect recipe: for each barrowful of shredded redwood bark, add two shovels full of creek sand, half a large coffee can of cottonseed meal and mix well. Recently, the Kolaks have used 38-0-0 microform crystals along with dolomite for extra nourishment. Although one gardening friend described the resulting mixture as "horticultural chicken soup," the recipe hardly makes the human mouth water. It's enough, however, to make the plants bloom wildly in gratitude.
While they patiently built up the soil and waited for the trees they had planted to provide sufficient relief from the sun, the Kolaks pondered the layout of their garden. "We think of this as sort of a Northwest garden in terms of appearance," Noel says. To that end, a soft, green lawn that serves as a path winds elegantly through the raised beds.
"It took a lot of contemplating and just sorting out," Ernie explains. Ernie put down a path of wood chips as a moveable visual aid. "That actually took several years," Ernie says of the path design. The result is a natural looking foil to the raised rhododendron beds.
Another aspect of the garden that surely received much thought is the actual arrangement of the plants. Opposite the front of the house is a group of Triflora, a subsection that is featured in abundance in the Kolak garden because the smaller leaves survive exposure to the sun very well. "They just bloom like mad," Ernie beams, "and they're really uncomplaining."

The idea for their arrangement came to Ernie as he admired the Triflora subsection at an early rhododendron show one year. He liked the way the deep blues of the various forms of Rhododendron augustinii blended with the soft shades of R. oreotrephes and on into the lighter R. rigidum . So he decided he would try to recreate that effect in the garden.
Another area, protected by the eucalyptus and redwoods, is what the Kolaks call "Maddenii Hill." The microclimate of the area helped determine the use of these plants, as maddeniis are susceptible to frost damage.
Dwarf rhododendrons mesh well with the Kolaks' overall preference for species. Behind a low brick wall off the back patio lies a close-to-eye-level bed where the dwarfs are displayed. Included, among others, are Rhododendron campylogynum , R. drumonium , R. flavidum , and an extremely compact from of R. pseudochrysanthum .
However hybrid rhododendrons are not absent either. To the right of the driveway is a large group including 'Crest,' 'Faggetter's Favourite', 'Exbury Naomi' and 'Lem's Cameo,' among others. A very large 'Loderi Venus' is a focal point in another area, and other hybrids in delicate shades can be found in various locations.

The companion plants that Noel in particular has placed throughout the garden seem equally happy. Trillium, Noel's "trademark," flourish in several different areas. In addition to Trillium chloropetalum and T. ovaturn , California natives indigenous to the Kolaks' garden, their collection now includes more than fifteen species. Other companions include giant Astfella chathamica that hug the bases of Pinus griffithii like spiky collars, contrasting with the gentle Clematis flammula and C. paniculata that cling to the trunks. These touches are the result of trips to New Zealand in 1984 and 1985 where the Kolaks saw the garden of Gordon and Annette Collier.
"It's the single greatest garden we've seen," says Ernie of the Colliers' five-acre hillside masterpiece. Noel's emerging interest in companion plants was encouraged by Gordon Collier when he visited the Kolaks' garden during the ARS Conference in 1981. "Being the garden architect he is, he saw exactly what our garden needed," Noel smiles. "And that was a lot of other kinds of plants to complement the rhododendrons."
They took his advice. Now, in addition to the trillium, the Kolaks combine other woodland plants such as the native Jack-in-the-Pulpit ( Arisaema triphyllum ), several species of dodecatheon, a number of different gingers and, of course, ferns. Their first erythroniums, a gift from Ed Dunn of Seattle, now seed themselves freely in the garden, as does Fritillaria meleagris . Hostas have also become an important component of the garden, their foliage colors and form contrasting nicely with the rhododendrons.
"We learned that it's hard to have a really successful, pleasing garden with only a few types of plant material," says Ernie. "We now try to combine companions for shape and contrast."
Companion shrubs such as Viburnum plicatum tomentosum 'Mariesii' and Japanese maple trees heighten the contrast. Ernie mentions their emphasis on native American ground covers that include Iris cristata , Shortia galacifolia and Galax aphylla , as well as Cornus canadensis and Houstonia caerulea . The herbaceous perennial Kirengeshoma palmata , despite its foreign origins, also has managed to creep in among the companions.
The variety of companion plants reflects the Kolaks' interest in overall garden design. "One of the most interesting things," Ernie says, "is figuring out what to do with a piece of land . . . deciding which plants to utilize and how to utilize them."
Although the Kolaks describe their garden's size as "mercifully, only an acre," they still have design plans for the future. Beyond their house is a small stable and corral that no longer hold horses. Despite its sentimental value - the couple met at a horse show - the Kolaks plan one day to convert the stable into a little summer garden house and develop a new planting area along side it.
Ernie says he would like to have one of the towering eucalyptus trees removed from the area to let in more light as well as do away with the greedy tree roots. Noel would like to leave certain sections of the corral fence, not only as a reminder of the past, but to add structure and provide support for some climbing plants - perhaps more clematis and even a few roses. Species and hybrid rhododendrons not found in other areas of the garden are likely to appear here, but the ideas are only in the planning stage. True to his character, Ernie plans to contemplate the layout for a while.

Martha Brockenbrough is an English and Classics major at Stanford University. Her brothers, Andy and John (also Stanford undergraduates) collaborated in the writing of this article. All three share an interest in rhododendrons, no doubt inherited from their parents, Ned and Jean Brockenbrough of Bellevue, Washington.

The Kolaks' garden will be one of several on the San Francisco Peninsula to be visited by those attending the ARS Convention in Oakland in April 1991.