Saturday, June 12, 2010

Dunn Gardens

Seattle is a city bedecked with horticultural jewels. This spring, I was delighted to visit one of them, the historic Dunn Garden. The garden is located in the Broadview neighborhood about 10 miles north of downtown Seattle. When the property was purchased by Arthur Dunn in 1914, the site offered sweeping vistas of Puget Sound and the Olympics, now veiled by mature trees. Arthur Dunn desired a summer country home for his family and he hired the Olmsted Brothers to design a landscape plan.

This renowned family firm is perhaps best known for designing Central Park in New York and the Capitol grounds in Washington DC. In a prodigious display of forward thinking, Seattle hired the Olmsteds to create a comprehensive plan for major parks throughout the city a little more than 50 years after the Denny party landed at Alki. Seattle's Olmsted park system has an extensive multi-site plan linked by boulevards and is recognized by subject matter experts as one of the best preserved and best designed in the U.S.

The Olmsteds' design philosophy was to retain and enhance the  natural beautyPhoto0253 and native vegetation of the site, working with the existing topography and integrating the planned landscape into its larger surroundings. It was characteristic of an Olmsted plan to include wide, curving boulevards and broad lawns, punctuated by stands of native trees and shrubs. The plan for the Dunn country place took advantage of the panoramic views and large stands of second-growth Douglas firs. Arthur Dunn, an avid and knowledgeable gardener, implemented the plan.

In 1947, Edward Dunn, the second child of Arthur and Jeanette Dunn, converted the garage on the property into his residence. He immediately began creating a woodland garden on the 2.5-acre site where the vegetable garden had been; he tended this garden until his death in 1991. The richness and diversity of the plantings include woodland plants such as erythroniums and trilliums, rhododendrons, and specimen flowering trees nestled beneath a canopy of fir and deciduous trees that remain from the original garden.

Ed Dunn left an endowment to preserve and maintain his portion of the estate. The E. B. Dunn Historic Garden Trust, established in 1993, now owns and manages the property. The resident curators, Charles Price and Glenn Withey, manage the garden’s daily operations. The Dunn Garden Trust's Board of Directors and the Garden Conservation Committee, direct the garden's rehabilitation and preservation.

The Olmsted characteristics to be preserved include certain iconic elements such as the curvilinear circulation system of drives and paths, the massing of plants, and the creation of various 'garden rooms', as well as the spatial relationships between the various landscape features. A spatial relationship is basically the adroit positioning of various elements in the landscape so that the result is greater than the sum of its parts. In an Olmsted design, open lawns are embellished with scattered trees and shrubs that choreograph a sequence of spatial relationships and views throughout the landscape. This defining feature is particularly evident in the design of the U.S. Capitol grounds. Photo0260

The Dunn Garden is listed on the  National Register of Historic Places. The National Register recognizes the garden's significance under two of its standard criteria. The property is noted both as an excellent example of Olmsted design, and for its association with Ed Dunn as someone who made important contributions to the field of horticulture. An enthusiastic gardener and prolific garden writer, Edward Dunn was respected as an authority on Pacific Northwest native plants. He was president of the Seattle Arboretum Foundation and guided the development of its Japanese Garden. He also served as president of the American Rhododendron Society. He was a founding member of the Species Rhododendron Society.

The best seasons to visit the Dunn Garden are in the early spring and in the fall. Early spring will feature snowdrops, magnolia, erythronium, hellebores and hepaticas. The show will continue through mid-May, when epimediums, trilliums, podophyllums, and ferns abound. Thanks to Arthur Dunn’s memories of his home in New York State, the garden includes many spectacular eastern hard­woods, some of which provide eye-popping fall color.

The gardens are open to the public on guided tours on Thursdays, Fridays, and Saturdays from April through July and September through October (closed in August). Admission is $10 for adults, $7 for senior citizens and students. Since private residences are still located on the grounds, admittance is by reservation only, and directions to the site are mailed only after reservations have been made. Children under 12 and pets are not admitted and parking is very limited. You can visit the website, for more information, photographs and reservations.

Visit the Dunn Garden to experience living horticultural history!

Monday, June 7, 2010

Container Maintainer

Before we leave the topic of containers (for now) I want to cover a few aspects of maintenance. The most important rule for containers is: don’t let the planted container dry out. The amount of water  needed to prevent that varies dSw hydrang potepending on several factors. Plastic containers and glazed pots retain moisture better than clay, wood or wire baskets. Containers placed in the shade will require less frequent watering than those in the sun. Some plants are moisture lovers, others don’t like “wet feet”. The weather influences moisture in outside containers. The only way to know when your pots need to be watered is to check them daily. You can either feel the soil, or test the containers weight-or both. Experience will equip you to determine your own plants’ needs.

When you water, moisten the entire root area-add water until it is running out of the drainage holes. If the potting mix is allowed to dry out, it is very difficult to re-wet. If this happens you may need to soak the container. You can submerge the pot in a larger container to the soil level. If the pot is too large, try putting a saucer under it or even a plastic bag around the base and up the sides and run the hose into the container until water stands. This is the only time you are allowed to let your containers stand in water! You should not normally have outside containers sitting in anything that would impede natural drainage. When water fills the air spaces between the soil particles, the roots are unable to function normally and the plants may die. If you must use a saucer-perhaps you have a second floor balcony-half fill the saucer with gravel and place the pot on top.

Remember that container plants planted in soilless mix depend on you for nutrients. Your new plants are accustomed to being pampered. Nurseries feed every time they water to keep plants looking their best. You can feed your container plants with a low nitrogen liquid fertilizer-something like a 5-10-10 ratio. Many people use a slow release encapsulated fertilizer, such as Osmacote. This is a great product, but soil temperature must be above 50 degrees for it to work. Here in the cool PNW, you will get fewer months of extended use. Some soilless mixes have slow release fertilizer incorporated. Either way, even if you do use slow release fertilizer, experts recommend using liquid fertilizer every 3-4 weeks.

To keep your container looking its best throughout the seasons, you will occasionally need to groom your plants. This includes dead-heading, which simply means to remove fad11-04-07_1507ed flowers. Some plants will respond with fresh new growth if you cut them back after they bloom. Annuals need to be refreshed in this way at least once during the summer. You may need to prune trees and shrubs  in containers to improve their structure. In the fall, clean up and  remove dead leaves. There is a marvelous book on maintenance called The Well Tended Perennial Garden by Tracy Di Sabato-Aust. It describes in detail what to cut back, when and why.

If you plan to leave your containers in place outside over the winter, choose plants that are hardy two zones colder than where you live, since the roots of plants in containers may experience more extreme cold than those growing in your garden. In our area, near Seattle, most of us are USDA zone 8 based on the average annual minimum temperature range. If you are close to the water it moderates the temperatures and you can push the hardiness zone a bit higher-so know your microclimate. Many Seattle area gardeners enjoy pushing the envelope and they are successful until we have the occasional below zero winter which wipes out their subtropicals.

Sw pinknorgange If you select plants that are marginally hardy in your area, you may be able to overwinter them by placing in an unheated garage or shed in the fall. Check them a couple of times during the winter-water if necessary. After the chance of frost is over, bring the pots outside, clean them up and water thoroughly. I have been able to overwinter jasmine and fuchsias in this way.

Now is a great time to experiment with your containers!

Sunday, June 6, 2010

Pots and Plants

Many people use annuals for all of their pots; annuals do well because they tend to have a long bloom period. But if you use a bigger pot and a variety of plants, you can still achieve steady bloom all season-and then right on through the winter. Not many annuals can do that! No plant is off limits; consider small trees, dwarf conifers, or shrubs with fall color, spring bloom or interesting shapes. Perennials are fantastic and diverse with varying bloom times for every season. Ornamental grasses provide structure and movement. Bulbs make lovely container plants and many are fragrant. Don’t forget edible plants for utility and beauty.

Whatever combination you choose, white potlook for  colors and textures of bloom, leaf, bark and fruit that please you and complement each other. Why not plant purple sage with a dark leaved geranium; or ‘Bright Lights’ Swiss chard with red twig dogwood and red leaved Bergenia; or white kale with blue fescue grass and white pansies? There are so many options, and so many beautiful combinations.

Try to select plants with similar cultural requirements to share a container. Cultural requirements include sun or shade, dry or wet, hardiness zone…But don’t stress; containers are, by nature, temporary. They are a great place to try out plant combinations before installing them in their permanent homes. Try color combinations that are totally unexpected. See how different foliage textures complement each other and create a design that is better than the sum of its parts. See what it actually means when a tag says “part shade.” If something doesn’t work, switch it out. A large part of the fun of containers is constantly improving on your design skills.

One design strategy that is Sw summer pinkparticularly effective in containers is called ‘color echo.’ Choose your plants so that part of one will echo the colors of another. For example, In this photo taken at Swanson’s Nursery, the magenta blooms of the Phygelius perfectly pick up the pink variegation in the leaves of the tri-color Hebe. It is a no fail way to unite your container while making it very diverse and interesting.

Another design principle is to consider the texture of your plants. A limited color scheme allows the textures of the plants to be of primary signiWM winter yellowficance. In this photo taken at Wells Medina Nursery,  there are no blooms at all in this group of pots, but there is considerable interest. The color palette is very limited-but look at the textures! Yucca ‘Color Guard’ has a bold, lance shaped leaf, Lonicera nitida ‘Baggeson’s Gold is tiny and ovate and Osmanthus ‘Goshiki’ is glossy and serrated. Contrast is provided by the dark, smooth, broad leaves of Bergenia. By the way, this photo was taken outside in mid November!

If you enjoy your perennial container enough to keep it for next year, give some thought to overwintering. Herbaceous perennials by definition die to the ground in winter and return the next spring. If you plan to keep the container in view of the house, make sure you have plenty of woody or evergreen specimens to provide interest in the winter. You can also opt to move some of the summer blooming herbaceous plants out of the container and into the garden for next year and refresh the container with plants that bloom in winter or early spring. (How about bulbs?)

A popular and easy recipe for successful container plant combinations has three components: thrillers, fillers and spillers. Every container should have a centerpiece that is big and bold; that is your thriller. Put that in the center if the pot will be seen from all sides. If you are planting a pot that will be up against a wall or a fence, plant your thriller in the back. Surround that with your filler plants; of course, the spillers go next to the rim where they can cascade down when they get big enough.

Place your plants still in their pots into the container to decide how you want to position them. This is a great idea when you are planting in the garden as well. Sometimes I will try a new plant in several locations-for several days-before I install it. I still end up moving plants multiple times which is a great source of amusement for my husband. He cautions me to never buy a plant that doesn’t come with its own little suitcase because he can guarantee that it is not going to stay in one place for long.

Once you have the plants positioned to your satisfaction, take them out of the pots. If you have a plant that is root bound, there will be very little soil and many roots when you take it out of the pot. If that happens, loosen the roots with your fingers and, if necessary, cut the roots in several places to allow them to spread out into the soil. The minimal damage you do will actually encourage the plant to put out new roots deep into the good soil. Once the plants are in place, fill in with your soilless mix and tamp down to set the plants firmly in place. Remember, we want at least 2” from the top of the soil to the rim of the pot so that the water won’t spill over the rim before it has a chance to soak in. when all is in place, water your container well.

My next post will fill you in on how to maintain, now that you’ve contained.