Winter Winners

That cold snap in early December, the harshest since 1991, was tough on many ornamental plants that usually look pretty good all winter here in the southern Willamette Valley. Some evergreen plants we have come to view as hardy, such as camellias and Mexican orange blossom, especially where exposed to morning sun, were quite badly scorched. So it was heartening to discover, on an early January visit to Gossler Farms Nursery (a garden well known for all-season interest) that most staples of the winter garden were looking fine.

In the Gosslers’ cozy office, I asked Roger Gossler the obvious question: If you could choose just one plant to add pep to the winter landsacpe, what would it be? Roger didn’t have to think long before responding, though he picked not one but two: hybrid hamamelis (witch hazel) and Cornus sanguinea ‘Midwinter Fire’. For much of the year, witch hazels don’t look all that exciting, as Roger pointed out. “But when you see one in full bloom in January you just want it so bad.” Fall color is excellent, too.

Many of the 50-odd witch hazels at Gosslers (mostly the Chinese Hamamelis mollis or Asian hybrids (H. x intermedia) were indeed blooming the first week in January, unfurling their skinny but abundant petals in bright yellow, light yellow, coppery orange or crimson, but they don’t all bloom at once. ‘Early Bright’ is perhaps 2 weeks ahead of the main season, Roger says, while the newer introduction ‘Angelly’ is in flower “clear into March.” Different colors are scattered through the planting that lines the main driveway, and Roger loves the way they carry the eye through the garden.

Most hamamelis varieties grow moderately slowly, to 12-15 feet tall in 30 years and about as wide, although the justly popular ‘Arnold Promise’, an upright grower with lots of bright yellow, fragrant flowers and magnificent fall color, may limit itself to 10 feet in width in sun. Witch hazels need very little pruning until they approach maturity, when the Gosslers recommend frequent, light thinning to keep them open and vigorous. If space is at a premium, Roger suggests you cut stems for the house when the shrub is in bloom, to keep a plant about 8 to 10 feet tall.

Roger’s other choice, Cornus sanguinea ‘Midwinter Fire’, is one of those shrubby dogwoods with colorful stems, sporting a vivid blend of yellow, orange and red. Young wood shows the brightest color, so Roger cuts the plants right down to about 8 inches in mid-March, “when the magnolias are blooming.” Even very small gardens can accommodate ‘Midwinter Fire’ when it is pruned this way. Golden fall foliage is the icing on the cake.

After some lengthy chat about witch hazels, I asked what else stands out. What about that pine that turns yellow in winter? (I had noticed a nine or ten foot specimen as I drove to the office.) This lodgepole pine (Pinus contorta var. latifolia ‘Chief Joseph’), discovered in the Wallowa Mountains by a hunter, looks much like any other lodgepole in the summer. About mid-October, depending on the weather, it turns bright yellow in the space of a week, then stays that way until March, when warmer temperatures cause it to green up again.

When I asked Roger’s mother, Marj, if she would contribute a favorite, she indicated a hybrid Asian mahonia (Mahonia x media) just outside the window. Most of the specimens at the nursery had lost their flowers and even showed some foliage burn from the cold, but this one, sheltered from morning sun, was more or less intact and blooming. Many gardeners avoid these magnificent Oregon grape relatives because they look so spiny, but Roger says that they are no problem once you get them in the ground! Their structural drama and fragrant winter bloom (much earlier than Oregon Grape) makes them worth the trouble. Annas hummingbirds love them, too.

You can see all these shrubs and many more outstanding garden plants at the Gosslers’ family run nursery, 1200 Weaver Road, Springfield. It is open Thursday, Friday and Saturday throughout the year. To visit at another time, call ahead (541-746-3922).
A fine book by Roger, Marj and Roger’s brother, Eric Gossler, was published recently by Timber Press. The Gossler Guide to the Best Hardy Shrubs is the culmination of many decades of experience, research and observation, discriminating plant selection and sheer love of plants. It is informative and entertaining and I heartily recommend it.

EW

PERENNIAL VEGGIES

I’ve been reading Perennial Vegetables by Eric Toensmeier (published by Chelsea Green). Did you know scarlet runner beans are perennial? I didn’t, even though I grew up eating runner beans and still consider the flat, rough textured pods more delicious than regular green beans. They are evidently useable as shell beans and dry beans as well. The Willamette Valley climate is probably marginal for over-wintering runner beans, but they might survive some of our winters in raised beds. I think I’ll try it, but people who live at the relatively frost-free coast may have more luck.

When Randy and I moved to a new house in September, we were partly escaping an arduously steep and sometimes icy driveway. But we also hope to become less car dependent and a little ‘greener’ in other ways as well: line dry the laundry when practical, generate some solar power, grow a little food, and take advantage of a fresh start to plant more natives, both for the benefit of bugs and birds and to cut down on summer watering.
There are other ways I can be a more responsible gardener. Trucking out yard debris and trucking in compost will be phased out to reduce fossil fuel consumption. That requires making room for a generous utility area for debris storage and composting.

Another way I can save on energy and materials is to stick with existing grades and hardscape features. The east side of our yard, where I am planning to plant natives, includes a formal rectangle of level grass bounded on three sides with concrete. I first considered removing some concrete in order to restore a more natural looking grade, but then it occurred to me this flat area is just the right size for a second food garden. It happens to contain our only outdoor water source and a fig tree that bears really good figs; building garden beds in there would justify leaving both in place.

I have a growing fascination with perennial vegetables. The concept may be novel to many people, since most of our food comes from annual crops. Perennial food plants are, however, mainstays of permaculture gardens, where one goal is to grow as much food as possible with a minimum of inputs, work and soil disturbance. And when you stop and think about it, most of us already eat a few perennials. Think asparagus, rhubarb, and artichokes. Sunchokes, watercress and walking onions are relatively familiar, too, but the bulk of Toensmeyer’s very long list of perennial veggies lie well beyond the average gardener’s consciousness (Atriplex, anyone? Good King Henry?).

Many of those plants originate in the tropics, so they are frost tender. Among the hardier sort, some are unacceptably invasive and some seem to be too much trouble to prepare. Others are just not that good to eat, or may take a lot of getting used to. After winnowing out the ones with significant negatives, we are left with respectable list that’s growable west of the Cascades. Personally, I am most interested in sea-kale, a cabbage relative that I picked on the south coast of England as a child; and in Good King Henry, which produces edible shoots early in the year. Climbing Malabar spinach and New Zealand spinach are probably too tender to over winter in the Valley. No such problem with French sorrel or celery-flavored lovage, though.

Perennial vegetables are a bit more self-sufficient than annual crops because they have larger root systems that go deep in the ground and forage for water and nutrients. And, of course, they entail less annual digging and tilling. Because of that, and because they do need scrupulous weeding, it makes sense to grow them in a seperate garden space from annual vegetables. Perennial herbs like fennel and chives can share the space, along with plants that draw beneficial insects. I’d like to try ‘forcing’ or blanching rhubarb, chicory and sea-kale under black plant pots with a brick on top. Forcing makes shoots a little earlier, more tender and milder tasting . Alas, I don’t own lovely terra cotta forcing pots like those in the picture.

Finding starts or seed of the less familiar perennial vegetables may be a challenge. Sea-kale seems to be available as plants from ForestFarm and as seed from JL Hudson. It is also grown as an ornamental for its cloud of little white flowers, so I can try flower seed sources as well. Good King Henry seeds, unless available at local seed swaps, may require an internet search or even a trip to Europe.

EW December 2009

Necessary Natives

My husband and I recently moved to a new house, and one goal I have for our new garden is to plant a sizable chunk of it with native shrubs and grasses. I look forward to planting vine maple, red flowering currant and mock orange, and perhaps ocean spray or Pacific ninebark. But all these shrubs are deciduous, and I would like some smallish evergreens as well, to keep things interesting in winter. Oregon grape is an obvious candidate, for wildlife value and its assertive leaves. There are already one or two plants of tall Oregon grape (Berberis aquifolium), and a little bit of shade where I can plant long leaf Oregon grape (Berberis nervosa). I’ve just planted my favorite, compact form of tall Oregon grape on a sunny corner, where it will develop great winter color. What else?

At first glance it may seems that, conifers aside, native evergreen shrubs are a little thin on the ground. But I am not going to be a purist about this native business, if that means limiting myself to species found right here in the Southern Willamette Valley. That’s just too strict for my gardener’s heart to contemplate. But if you interpret ‘native’ as indigenous not only to the Willamette Valley but to all of Western Oregon the list of plausible evergreens grows quite long and various. Local nurseries have long sold Oregon wax myrtle and kinnickinnick, which are not valley natives. Including other species from the coast and from the mountains provides the wonderful evergreen huckleberry (Vaccinium ovatum), native rhododendron (Rhododendron macrophyllum), coast silk tassel (Garrya elliptica) and even, for those of us with some very free draining soil, manzanita.

Hairy Manzanita (Arctostaphylos columbiana) does belong in the valley, according to my references, but we don’t see it often. There are other less familiar valley and foothill natives, such as buckbrush (Ceonothus cuneatus), an evergreen ceonothus that can grow to 8 feet. Two smaller plants in this category that particularly interest me are coyote brush and Oregon boxwood. Sun-loving coyote brush (Baccharis pilularis) has small, silvery green leaves and fall flowers that are attractive to insects. Deer do not seem to eat it. At four to eight feet this is not always a small shrub, but it seems to tolerate considerable pruning, and the leaf color is appealing. It’s not a common plant in nurseries, but Fern Hill Nursery in Cottage Grove sells it. I’m thinking of making a coyote brush hedge.

Oregon boxwood (Pachistima myrsinites), also called mountain lover (and sometimes spelled paxistima), is common in the mountains and occasional in the foothills. It has little dark green leaves and a dainty way of growing. Last spring I noticed it teaming up with beargrass, right at the edge of the cliff above Tamolitch Pool on the McKenzie River. They made a lively combination that I hope to reproduce just as soon as I can provide a gritty slope in light shade. Oregon box is not always easy to please, but it is well worth trying if you want a native, shade-loving low-growing evergreen (1 to 3 feet). Unfortunately it is difficult to find. ForestFarm in Williams, Oregon lists it but is currently out of stock.

EW November 2009

Late Summer Blues

The last weeks of summer feature three of my favorite blue-flowered plants: a perennial, a sub-shrub and a potentially large bush. Besides their lavender blue flowers and a late blooming time, they have several things in common. All three appreciate good drainage and lots of sunshine, are loved by butterflies and are pretty much deer-resistant. Although they are easy to grow in ordinary garden conditions, they are relatively drought tolerant and adapt well to low-water landscapes.

Anise hyssop (Agastache foeniculum) is a tough perennial in the mint family, native to the prairie states of North America. You can get it from nurseries that specialize in prairie plants but it’s somewhat easier, these days, to find ‘Blue Fortune’, a hybrid between anise hyssop and a similar plant from Asia named Agastache rugosa. Both anise hyssop and ‘Blue Fortune’ grow 2-4 feet tall, and do best in full sun in dryish, well drained soil. Their slowly lengthening, cylindrical spikes are packed with small flowers that open over a long season and look great with rudbeckia, echinacea, tall sedum and grasses. They are hardier than the agastaches called hummingbird mint, which can have trouble with our wet winters.

Blue mist shrub (Caryopteris x clandonensis), also known as bluebeard or blue spiraea, is a small Asian shrub with fragrant grey-green leaves that blooms on new wood. In cold climates, the topgrowth dies back in winter. Even in mild climates it looks best if cut back in spring. Pruning by one half or more as the buds break keeps it tidy and vigorous. Small flowers are produced over a long period along the top few inches of new growth. Two varieties popular for their strong flower color are ‘Longwood Blue’ and ‘Dark Knight’. Both are rather upright plants that can reach 4 feet.

My favorite caryopteris is ‘Heavenly Blue’. It has powder blue flowers and an excellently neat, mounding habit but it has become very difficult to find. I recently read about a new variety with deeper colored flowers named ‘First Choice’. It is said to grow 2-3 feet tall (after pruning) and may turn out to be an acceptable substitute for ‘Heavenly Blue’. Another low-growing variety is ‘Worcester Gold’, named for its yellow foliage. All these compact varieties look best where they are not crowded in by other plants and can show off their shapely hummocks. They look great in gravel gardens with rocks, small grasses and strongly architectural plants such as yucca and New Zealand flax.

And now the big one. Chastetree (Vitex agnus-castus) is an aromatic shrub from the Mediterranean. Like caryopteris it blooms on new growth, and can be pruned quite hard in spring if you need to restrict it growth. In this climate, it is more often grown with minimal pruning as a large bush or small tree and can eventually reach 10 - 15 feet. Vitex leafs out quite late in spring and quickly produces new shoots clad with attractive three-part leaves. Each shoot terminates in a densely packed, tapering pyramid of bloom. Vitex extracts have been used since ancient times to regulate the menstrual cycle and promote female fertility. I just know that pollinators love the flowers of this late bloomer, and our voracious deer have never bothered it.

Back to Nature

This past Mothers Day, at least 500 people attended Eugene’s first native plant garden tour. Organized by the Native Gardening Awareness Program (NGAP, a committee of the Emerald Chapter Native Plant Society of Oregon) the tour gave native plant enthusiasts and curious gardeners an opportunity to visit four public and eight private gardens where native plants play an important role. The private gardens varied greatly in age, setting, style and strategy, making for an interesting tour.

Aryana Ferguson and Bart Johnson’s yard adjoining Tugman Park is about 80% native and relatively mature: the formative “big push” came in 2003. Now salamanders make a home here, hummingbirds abound, chickadees and flickers squabble over who will nest in a snag and a hairstreak butterfly has laid eggs on the checker mallow. The day of the tour, the sunny front yard was ablaze with a pink froth of annual rosy plectritis intermingled with native buttercups, all busy with insect pollinators. I returned at the end of June to talk with the owners about their garden and the makeover experience, and was greeted by a whole new crop of flowers.

These people are pros. Ferguson has worked in resource management for 19 years and currently owns Madrona Consulting, working as project manager for a variety of restoration projects. Johnson, a professor at the University of Oregon, is an ecologist and landscape architect who works to merge ecological function with form and beauty. We talked on a deck overlooking the back yard, where they’ve kept a number of mature non-native plants – trees, mostly, and a few shrubs, which contribute both shade and structure.

When I toured this garden in May I was struck by its use of sedges and grasses, so prevalent in nature but often omitted from native gardens. A central feature of the back yard is a swale designed to take runoff from the roof. Sedges flourish here. Slough sedge (Carex obnupta) seems to be the most satisfactory – it likes semi-shade and stands up well. Uphill from the slough, in dappled shade, is a soft, bluish green lawn consisting mostly of Roemer’s fescue. “We mow every two weeks to keep the fescue from shading itself out” said Johnson, “ and we have to weed out exotic forbs and grasses.” Still, he’s surprised how little work it’s been.

As we toured the garden, Ferguson indicated a taller grass: “California fescue is a good bunch grass, especially in winter, when it looks really pretty,” she said. Johnson commented on big chunks of log scattered here and there among the plantings. “Put out some large wood out for salamanders and snakes. They love it.” We passed a sizable patch of camas (“it seeded in here on its own”) prompting the comment that camas is one of the easier plants to grow. Once it dies down you can mulch over it. Oregon iris is another winner. It is easy to weed around the clumps and, unlike camas, it stays green all summer.

Although their own garden was a radical makeover, Ferguson and Johnson now advise people to start small. “Don’t try to convert everything to natives all at once,” Johnson suggested. “Start from less diversity and add more as you can handle it,” he said, “and plant clumping things you can mulch around, he emphasizes. “The easiest native garden to manage is one of shrubs, sedges and ferns, in shade.” You can’t mulch prairie because you want things to self sow, so weeds are a bigger problem. Establish patches of easy perennials first, and mulch to reduce weeding. Fill in with annuals later.

In their sunny front yard, the couple removed weed cloth, bark mulch and the standard issue landscape shrubs, then sheet mulched with cardboard and two inches of mycorrhizal soil from Lane Forest Products to get a fresh start. Now a mix of prairie species with some from bright woodland, this area is still a work in progress. “We began by throwing out a lot of seed to create high diversity mixes of species,” said Ferguson, “and it didn’t work. We redid it with an effort at an aesthetic people are more used to.” Grasses are allowed only in clumps; perennial forbs are corralled in well-defined groups. “Each year we bring a little more order to it,” she said.

EW July 2009

Scent of the Rogue

One of the highlights of a raft trip down the Rogue River a few years ago was the glorious sight and scent of native azaleas that covered some stretches of the river bank. The azalea was Rhododendron occidentale, a deciduous shrub that occurs in a coast-hugging strip from Santa Cruz county, California to Coos County, Oregon, from sea level to 9000 feet.

Western azalea is one of only three native rhododendron species that are found west of the Rocky Mountains. Pacific rhododendron (Rhododendron macrophyllum) is the most familiar. This big evergreen is plentiful in the coastal forests of Oregon and Washington and on the western slope of the Cascades. It is easy to grow and makes a nice addition to irrigated gardens. Cascade azalea (Rhododendron albiflorum), is hard to cultivate and seems scarce even in its native habitat. I’ve hiked the Cascades for years and have seen it only a handful of times.

The gem among our three rhododendron species is Western azalea. Like many wild plants it is highly variable, growing from three to 15 feet in height and occasionally more. The flowers are generally white with a yellow blotch inside, but they are often tinged with pink or even red, and range in size from a little over an inch across to nearly four inches. This fabulously fragrant shrub has tempted hybridizers for 150 years, primarily in Europe, contributing its perfume to the famous Exbury line of deciduous azaleas and to hybrids such as ‘Irene Koster’.

Over the last century, here in the Northwest, a handful of collectors catalogued, selected and distributed some particularly fine forms of the species itself. Today these plants are relatively hard to find in nurseries, but Greer Gardens lists several varieties.
I have two plants I bought as babies from local plant sales. About ten years on, they are less than three feet high, with modest but shapely flowers just shy of an inch and a half across. One has particularly colorful buds, with a strong pink flush and a distinct line of color along the outside of each petal. This is a striking occidentale feature that comes through in ‘Irene Koster’.

It’s a thrill to encounter Western azalea along the Rogue or in the Siskiyous. It is pretty darn nice in the garden, too, blooming quite late in the rhododendron season when most deciduous azaleas are over. Wild inland and mountain populations grow near streams, rivers and springs, indicating a liking for moisture. But it tolerates periods of dryness between waterings in summer, especially with some shade. It also tolerates soggy soil in winter, and the leaves seem to be less susceptible to the powdery mildew that often disfigures other deciduous azaleas by late summer.

What is an azalea, anyway? Botanically speaking, all azaleas are rhododendrons, so what justifies calling them by another name? There are a number of features that separate azaleas from rhodies, although none seems to be completely reliable. The easiest to grasp is the number of stamens per flower: five in azaleas (occasionally six to ten), and ten or more in rhododendrons. This works most of the time. Interestingly, the Cascade azalea I mentioned earlier is sometimes called ‘white rhododendron’. How many stamens does it have? Ten.

EW June 2009

BUZZ BUZZ BUZZ

Lots of people are keeping honeybees these days. That seems like a good idea, since wild honeybees have more or less disappeared. Keeping bees increases the bee population generally and provides pollinators for your own garden (and the possibility of your own honey).

Like most people, I am alarmed by colony collapse disorder, mites and the decline in honeybees. After all, much of the food we eat is dependant, directly or indirectly, on honeybees. Conventional mass production of tree fruit and almonds would be almost impossible without this colony-dwelling bee that can be driven about the country in hefty numbers and put to work wherever bees are needed to pollinate enormous monocultures. No wonder honeybees are stressed out.

Unlike a Central Valley almond grower, however, the average home gardener should be able to get by without the honeybee, which is not native. A healthy population of native pollinators could probably do the job. There are thousands of native bee species in the US, not to mention other types of pollinating insect. Sadly, many of the same factors that hit honeybees affect native bees as well. In fact pollinators of all kinds are disappearing.

One element behind this decline is undoubtedly the loss of pollinator-friendly habitat, through development, conventional agriculture and widespread pesticide application. Native bees are affected too; they are also becoming infected with diseases and parasites spread by honeybees. All the same, non-honeybees out-number honeybees in my garden. Bumblebees have been particularly conspicuous.

Like honeybees, bumblebees are social insects, forming small colonies. Other kinds of native bees (mason bees, for example) are solitary; that is, individual bees don’t interact with one another. There may be many about at the same time, but they don’t cooperate.
The value of native bees in agriculture is beginning to get some attention. Bumblebees, it seems, venture out at lower temperatures than honeybees and even tolerate a bit of rain - valuable traits if you have early-flowering crops to pollinate. And all native bees, adapted to their work by coevolving with the plants they pollinate, can be as much as 100 times as efficient at it.

While many native bees are specialists, visiting only a certain kind of flower, bumblebees and some others are ‘generalists’ that are happy to visit your apples, squash and so on. What can we do to encourage them? Solitary bees lay their eggs in bark crevices and hollow stems, and occasionally in man-made, purpose-built accommodations. Some bees need a certain amount of bare, uncultivated ground (without a thick covering of bark mulch!). Bumblebees nest in cavities in the ground, or beneath planks or inverted plant pots.

Slightly untidy gardens may have the edge here. Pesticides are out of the question, needless cultivation should be avoided, debris piles and weed patches are great. When it come to nectar sources, many of the plants that attract the honeybee also attract native generalists. Lavender and oregano, both from the Mediterranean, are magnets to both. Native plants, however, have been shown to support a larger and more diverse population of native insects, including bees. A quick internet search on ‘plants for pollinators Oregon’ will yield a wealth of information.

EW May 2009