In Holland between 1634 and 1637, tulip bulbs that produced flowers with irregular stripes, streaks, and feathery patterns cost thousands of dollars. But those who bought the tulip bulbs in this era of tulipomania were regularly disappointed. They discovered that the seeds of the bulbs didn’t produce tulips that were “broken,” as these bi-colored flowers were described. Moreover, each season, the bulbs’ flowers were fewer and weaker. Although the little bulbs that grew off the parent bulb (called offsets) produced broken flowers, the next-gen bulbs were always less productive than their parent.
It turned out that the source of the spectacular patterns was one of the dozen tulip viruses. Unfortunately, the virus weakened the plant, and ultimately the genetic line of a bulb would die out.
In the early 1980s, the Dutch government outlawed the sale of virus-infected tulips. But the flowers pictured here are not illegals. Today’s tulip breeders have manipulated the genetics of tulips to produce patterns, so you can buy bulbs that produce flowers that recall the seventeenth-century beauties, but will bloom exuberantly for many years.
My book group read Rebecca by Daphne du Maurier this month, and we were all surprised by the descriptions of deeply fragrant azaleas at Manderlay in Cornwall. Around Washington, DC, the azaleas we know, while beautiful, are unscented. Why?
Azaleas are members of the rhododendron genus, and are closely related to the woodland rhododendrons. Most azaleas with scent are deciduous, so they lose their leaves in the fall. Most unscented azaleas are evergreen. Around Washington, DC, azaleas are often used as foundation-hiding plantings, so the evergreen (and therefore unscented) varieties are more popular.
About 1900––a few decades before du Maurier wrote Rebecca––Lionel de Rothschild fell in love with deciduous azaleas and bred his own cultivars at his Exbury estate in Hampshire (not far from Cornwall.) Some of the “Exburys” are particularly fragrant, so the second Mrs. de Winter may well have been entranced by Exburys.
This year, we lost a number of backyard shrubs to a particularly cold winter. I’m looking at deciduous azaleas as replacements. Not only do they provide fragrance, their leaves turn shades of bright orange, yellow, and gold in the fall.
In my yard in suburban Maryland, hellebores are the first of the spring flowers. This year, despite the unusually cold weather, they were up as early as ever. Even so, I know they’ll be in bloom for weeks and even months. What makes them such persistent bloomers?
For one, their petals are not really petals. They’re colored sepals, the leaves that cover and protect a developing flower bud. Because sepals are tougher than petals, they last longer. After the flower has been fertilized, the sepals’ pigments decay and the green pigment, chlorophyll, becomes evident. The longer the green sepals persist, the bigger the plant’s seeds. That’s probably because the sepals are photosynthesizing, enabling the plant to gather more solar energy and make more carbohydrates.
So, where are the hellebore’s petals? They have evolved into the little green leaves you can see at the base of the many stamens. (There can be up to 150 per flower.) The little leaves are known as “honey leaves,” and are actually nectaries that lure insect pollinators. No same old, same old about hellebores.
One of the most interesting and easy plants for cold climate gardeners is the Coffea arabica. I’ve had a potted one for years. It lives in a shady spot in the backyard in summer. In the colder months, I move it indoors to an east-facing window. Last May, per usual, my tree (about five-feet tall because I prune it regularly) produced a crop of small, white flowers. Nine months later, I have very ripe coffee cherries. (You can see the remains of the flowers at the tips of the cherries.) Inside each cherry are two coffee beans, which are the seeds of the coffee plant.
I’ve never tried to roast the beans (too much trouble and a home oven isn’t great for roasting coffee), but yesterday I tested a cherry. There’s not much pulp on it, but what there is, is deliciously sweet. In countries where coffee is grown, sometimes the pulp is dried and used as a tea. The tea, called cascara, is rich in antioxidants. Now, a Hawaiian company called Kona Red is producing a coffee berry juice. Last week, Walmart began offering the juice in 2,100 of its stores. I may have a new use for my next crop!
This lovely drawing by Eva-Maria Ruhl is a family portrait of the Leyland cypress (in the middle), that ubiquitous suburban conifer. I was delighted to write a guest rant for Gardenrant.com, and let off some steam about Leylands, or rather the way they’re misused in landscaping.
The Leyland is the offspring of two venerable North American conifers native to the West Coast, the Monterey cypress (on the left) and the Nootka cypress (on the right). The pair never would have met in their native habitats: The southernmost Nootka grows 400 miles north of the Monterey. But in the late 1800s, Christopher Leyland, a wealthy English banker, gave his nephew John an estate in southern Wales as a wedding present. John’s landscape architect installed a variety of exotic trees, including a Nootka and a Monterey. In 1888, the seed of one species and pollen of the other had a sexual encounter, and a hybrid seed sprouted.
When John’s son Christopher inherited the estate the next year, he cultivated the hybrids. Christopher Leyland’s seedlings prospered and became known as the Leyland cypress (Cupressus x leylandii). Leylands are sterile, but they are readily grown from cuttings. The problem is that suburbanites, in hopes of quickly creating a privacy screen, usually plant the saplings far too close together. As they grow taller (and they can add three feet per year), they shade one another, and become distorted and spindly and downright dangerous.
Morrow/HarperCollins just released my new book, A Garden of Marvels. As part of the promotion for the book, I am guest posting on gardening blogs. Yesterday I was featured at Cold Climate Gardening where I explain why growing a kumquat tree is a great idea even for northern gardeners. Coming soon: a guest rant about Leyland cypresses on GardenRants.com. I’ll also be speaking soon at Politics and Prose bookstore, the U.S. Botanical Garden, the Adkins Arboretum, the Missouri Botanical Garden, and other sites. You can see my schedule so far at RuthKassinger.com.
Some of the most beautiful trees in winter are sycamore, birch, crape myrtle, and other species with exfoliating bark. Thin layers of bark peel off the trunks and branches of these species, which gives them an interesting, flaky texture like the top layers of an oven-crisped spanikopita. Before they blow away, the layers come in a range of browns, reds, oranges, and grays. Adding to the chromatic richness, the smooth new bark underneath is often multicolored, sometimes even green.
Botanists still aren’t sure why certain trees have evolved exfoliating outer bark. Outer bark is made of dead tissue. Non-exfoliating trees like oaks have trunks and branches that develop furrow-like gaps in their outer bark as they grow in diameter. Each spring, living, inner bark tissue forms a new protective coat for the tree. For exfoliating trees, which have smooth outer bark, the peeling––and the formation new layers––may allow the tree to safely expand.
Another possibility is that trees with thin bark evolved exfoliation to deal with pests. Thick bark confounds insects, bacteria, and fungi that might otherwise tap the sugars that flow beneath the bark. Exfoliating trees, by shedding their bark, also shed themselves of perilous hangers-on. The scientific jury’s out, but the verdict from my one-woman aesthetic jury? Thumbs up on exfoliating bark.