California Landscape Design

Above photo courtesy of Francesca Corra, APLD.

The Proof is in the Trials

by Cheryl Buckwalter
Landscape Liaisons
APLD Sacramento District Member & Sustainability Chair

While I usually am not a “rose enthusiast”, I learned about the Sunny Knock Out Rose while participating in a UC Landscape Plant Trials Open House at UC Davis in the spring of last year. I was very impressed with and LOVED this plant – the flowers were fragrant, there were bright yellow and cream-colored flowers on the plant at the same time, and the foliage was the richest green I’d seen on any plant in a very long time! So that’s why it’s now (one of) my favorite plants, but don’t just take my word for it, let’s see excerpts from on-line plant descriptions and then results of actual University of California research-based trials.

Online descriptions about the Sunny Knock Out Rose tout sweet-smelling flowers, similar to Citrus; long-lasting color, bright, lemony-yellow flowers that open bright golden yellow, age to soft buttery hue; deep, green foliage; low maintenance, disease and pest resistant, and drought tolerant. Wow! Who wouldn’t love this plant.

The University of California (UC) Landscape Plant Irrigation Trials were begun to address the growing need for landscape plants that require fewer chemicals and less water. Since 2006, California native, UC Arboretum All-Stars, and new cultivars of plants have, and continue to be, evaluated by UC Davis horticulturists and researchers, horticultural professionals, UC Cooperative Extension Master Gardeners, APLD members, and others. Trial Researchers include UC Cooperative Extension Environmental Horticulture Advisor and Project Lead Karrie Reid and Landscape Horticulture Specialist Lorence R. Oki, California Center for Urban Horticulture Executive Director Dave Fujino, and UC Davis Plant Sciences Staff Research Associate Jared A. Sisneroz.

Trials for specific plants span a two-year period of time. After one year on a regular watering regime for plant establishment, plants are irrigated according to Low, Moderate, and High, treatments that correspond to Water Use Classification of Landscape Species (WUCOLS IV). Plants are evaluated for their overall appearance, foliage quality, flower quantity, pest tolerance, disease resistance, and vigor.

These trials yield validated irrigation recommendations that can be used in developing water budgets required by the Model Water Efficient Landscape Ordinance (MWELO) and expose industry professionals to new plants that are being introduced to the trade.

Especially in the State of California where outdoor water-use efficiency is a must, these research trials need to continue, and I’m proud to report that, recently, APLD-CA provided a letter of support for a grant proposal that Oki, Reid, and their colleagues submitted to the Horticultural Research Institute (HRI).

To learn more about these research trials, visit UC Landscape Plant Irrigation Trials.

A sneak peak of the results from the UC research trials for Rosa x ‘Radsunny’, Sunny Knock Out reveals the following details:

The plant was good at self-cleaning spent blossoms and maintained a mostly uniformly rounded habit (final height 31”, width 50”) with an occasional horizontal branch thrown out near the base of the plant. These are easily pruned out. Flowers covered plants in May, with the highest rebloom percentage averaging 50% coverage on the 50% ETo treatment.  After July, only the 50% irrigation treatment had acceptable average foliage ratings while higher and lower treatments had an unacceptable level of pest damage on the higher treatment and stress damage on the lowest. With average flowering between 20 to 50% coverage, the plants on moderate irrigation (50% of ETo), averaged the best overall appearance ratings. There were no significant differences in growth between treatments. It should be noted that the 50% irrigation treatment was watered on average every 23 days with about 14 gallons of water per plant (2.7”).

There you have it, so now I ask: Would the Sunny Knock Out Rose be a beautiful addition to your garden or your client’s? I say, Yes! And while you’re at it, why not conduct your own not-so-scientific, but just as important, research.

A Day in Watsonville with the APLD Bay Area District

by Marcy Lotti-McCarrell, APLD Bay Area District Member and Programs Chair

On May 18, I had the pleasure of spending the day roaming the hills of Watsonville with 20+ fellow plant-a-holics as we toured three of Central California’s most unique nurseries. Living in the South Bay I had visited these nurseries before, but nothing could have prepared me for the amazing ‘behind the scenes’ look and royal treatment we received as APLD members.

We began our day at Monterey Bay Nursery, with the fog still swirling around our feet. As we drank coffee and ate scones and fruit, we roamed through the beautiful displays of their new introductions and high impact plants. We heard from co-owner Manuel Morales about the history of the 13-year-old company and partner Luen Miller shared with us new trends in propagation, how they select plants to be propagated, and how they prevent the spread of viruses via clippers.

Monterey Bay Nursery prides itself on its new introductions, unique plant varieties, and what they call ‘current trend’ and ‘new wave’ perennials. They have many Mediterranean plants as well as Australian, South African, and California natives. As usual, our group had many questions and we had to be rushed off to our next stop while still talking! A line from the Monterey Bay Nursery website sums up our experience, “we are all very nice people, and we really, really like plants.” My personal favorite was the Ligularia gigantea and the Grevillea 'Peaches and Cream'.

Next it was onto the Pajaro Valley and Sierra Azul Nursery and Gardens. Sierra Azul is a retail nursery specializing in plants grown in the five Mediterranean climate zones. We had a wonderful lunch, organized by Robin Salsburg, while we listened to Jeff Rosendale, the nursery owner, tell us about the history of the nursery and the conception of their two-acre demonstration garden. Many of the plants they grow can be seen in mature form in this garden. We meandered through the demonstration garden on a guided tour and received many insights into growing and caring for these unique species. There were several points in the tour where we had to run into the retail nursery to find something we just had to have, and to take another for a friend we knew couldn’t live without it!  With our plant passion as our common language, we made new best friends all day.

Sierra Azul has an annual Art in the Garden Event in June with over 100 local artists who make ‘Garden Friendly Art’. We were able to get a preview of this year’s sculptural offerings. It is well worth visiting during this time of year. I went home with my pockets a little lighter, having purchased a ‘Sally Greenwood’ and Salvia ’Dazzler’, as well as a ceramic artichoke I had been coveting for years!

Well fed and happy (having satisfied both our hunger and our retail urges), we made our way to Suncrest Nurseries, who provided a beautiful venue and plant presentation. Suncrest specializes in California Native plants and is enthusiastic about preserving them. From the large-scale specimen plants flanking the tented area, to the beautiful array of their new introductions and somewhat forgotten plants, everything was perfect. There were silver trays with tea cookies and a beautiful brochure with their new introductions.

We heard from Suncrest’s president Christine Jennifer about where their business is going, as well as some of the challenges they face in the nursery industry.  Dell McComb, the director of horticulture, pleased the crowd with so much information, I couldn’t write fast enough. He talked about some old favorites, such as Asarum caudatum and Erigeron 'Ron's Pink', as well as a beautiful new Sedum ‘Blue Pearl’. Dell’s current area of interest is in developing a group of plants that are certified biodynamic. This certification would apply to medicinal and culinary plants, fruits, and habitat plants. At this point, they have obtained the certification for several of their herbs and beneficials. Once again our questions over ran our time with Dell, the only thing that saved him was that we wanted to buy plants!

Exhausted and happy, we navigated our way out of the rolling hills of Watsonville and back to civilization. I thought about how fortunate I was to be part of an organization that allows me to meet and spend time with people who share my passion, as well as have access to experts in the field. I am certain that the nurseryfolk we met during the day felt this passion as well, and will remember APLD as a group of intelligent and experienced designers and horticulturists who share their vision and can help them spread their message.

If you were not able to join us for this trip, come to the APLD Bay Area Designer Plant Fair on August 14th at the Veteran’s Memorial Building in Lafayette. Our amazing sponsors will dazzle you with new plant introductions, hot trends, and lots of plants to take home!

Catching up with APLD San Diego District