Q: I have heard that blue is the rarest color among flowers. Nevertheless, I am determined to plant a garden of nothing but blue-flowered plants. I have already planted lobelia, plumbago and delphinium. Can you give me some other suggestions?
– Melody Paxson
Pasadena
A: You are correct to identify blue as an exotic flower color. The quest for the true blue flower is nearly as mythical as the search for the yellow petunia or the black tulip. People have trekked for weeks along botanical expeditions to the Himalayas for the sole purpose of seeing true blue poppies (Meconopsis species) growing in the wild.
Many times, what we identify as blue is actually a shade of lavender, violet or purple. For instance, flowers of the so-called blue potato bush (Lycianthes rantoneii) and of the blue hibiscus (Alyogyne Huegelii) are far more violet than blue in color. The most authentic blue flowers we can lay claim to among ornamentals commonly seen in area gardens are not intensely colored; they are pale blue, sky blue, baby blue or powder blue.
You should definitely explore the blue bearded irises. Bearded irises are among the easiest plants to grow in this area. They are native to Mediterranean climates like our own and bloom most heavily in late winter and spring. An excellent collection of irises can be viewed at the Descanso Gardens in La Canada Flintridge. Locate them at the back of the highly educational Descanso Rosarium.
You should also try Geranium “Johnson’s Blue,” a true geranium with lacy leaves and 2-inch-wide flowers. True geraniums have a more delicate growth habit than common geraniums (which are actually pelargoniums). True geraniums make fine, noninvasive ground covers for close-up viewing near entryways and patios. They will spill gracefully out of flower pots and hanging baskets. They grow best in half-day sun.
Forget-me-not (Myosotis sylvatica) is another blue-flowered plant for half-day sun. Forget-me-nots will naturalize or take over an area due to their self-sowing capacity.
Anchusa azurea is a pure blue relative of forget-me-not that is suited to full sun and thrives in all climates. Anchusa (an-koo-zuh) requires a minimal amount of water and will spread over large, out of the way areas where regular maintenance would be a problem.
Speedwells (Veronica species) are heavy-blooming perennial ground covers, often in blue, that grace the garden in spring and summer. They are popular fare in mail-order plant catalogs and hard to resist, but seldom survive in Valley gardens for more than two or three years.
Other blue-flowered perennials worth mentioning would include: licorice-scented giant hyssop (Agastache foeniculum), bluebeard (Caryopteris species), Salvia uglinosa and catmint (Nepeta faassenii). And don’t forget California natives such as the many Ceanothus species and Penstemon heterophyllus “Blue Bedder.”
Q: Is this a good time of year to prune eucalyptus trees?
– Arthur Weston
Canoga Park
< A: Some experts advise against pruning eucalyptus trees between May and November because of the bark beetles that are active during this time. Tree sap, which is attractive to beetles, accumulates where pruning cuts are made. By the same token, eucalyptus trees - especially when located in irrigated lawns - are highly susceptible to branch breakage during the summer months so you might want to do some light pruning if you start to see branches falling from your tree. In summer, eucalyptus trees take up water without conscience and may become top heavy as a result. TIP OF THE WEEK: There is evidence that certain chemicals, injected into the trunks of eucalyptus trees, can be effective in combating the redgum lerp psyllid that has been a plague on Valley eucalyptus trees over the past two years. More information on this treatment and its results can be found at www.mauget.com. Certified arborists, listed in the yellow pages, are qualified to provide such treatments should you decide to utilize them. Garden Wonders GARDENER: Marshall and Sharon Maydeck RESIDENCE: Arleta PLANT OF INTEREST: Redwood Marshall Maydeck loves his redwood. The tree doesn't rise imposingly into the sky (it's just over 20 feet tall). Nor is Maydeck constantly hailed from the road by motorists wondering where he found the tree, how he grew it, where they can get one of their own. But Maydeck loves his tree all the same. ``The redwood is gorgeous,'' he says. ``My wife and I will generally sit on our front deck in the evening with a glass of wine, and I bet you 50 percent of our conversation goes around the tree. We love its stately beauty - the serenity of it. ``We don't consider ourselves owners of the tree; we consider ourselves caretakers of the tree.'' The Maydecks bought their redwood in 1989, while vacationing at Fort Bragg. The tree was a mere 8 inches tall, skinny. Now it's 30 times that height, with a 2-foot circumference. These figures aren't that unusual - redwoods normally put on 3 to 5 feet of growth a year. Still, what the tree lacks in physical stature is more than made up for in sentimental value. ``I'm native-born, so I've always loved redwoods,'' Maydeck says. ``They're so symmetrical, so perfectly shaped. I wish more people would plant them. Everybody thinks redwoods are slow-growing. Such is not the case.'' MAINTENANCE: During the holidays, Maydeck wraps lights around the tree, but aside from that, it remains untouched. ``When I first planted it, I did have to water it, but I haven't had to do anything since,'' he says. ``I've never had to give it anything but fondness.'' WHAT JOSHUA SISKIN SAYS: ``Redwoods don't do real well in the Valley - it's not a tree for full Valley sun. Redwoods will never grow as tall in L.A. as they would in their natural habitat, where they can grow up to 300 feet tall. The tallest ones I've ever seen here are 80 feet tall, in the canyons. ``A redwood is a conifer, and conifers tend to be low-maintenance and drought tolerant. If you have a house that has light coming in on a couple of sides, but is still protected from full sun, you could probably grow a redwood.''