Many local gardeners wait with great anticipation for blooming and potted dahlias to start showing up in the garden centers and from the vendors at the farmers markets.
That is happening now, allowing us to examine the flowers and choose those that most appeal, those that will work best in arrangements, and those that will look most stunning in our individual garden spaces. In pre-pandemic years, we could also get many of our plants at a major cost savings during the annual Monterey Bay Dahlia Society tuber sale in early spring.
Hopefully Monterey Bay Dahlia Society will be able to resume their in-person sales by next year. In the meantime, if you have an empty spot and want fabulous color and form, and yearn for enough dahlia flowers to fill arrangements, visit your favorite garden center to select from the many pots on display.
Why do so many of us love dahlias? First of course is the amazing diversity of form, color and size of the blossoms. In every color and combination but true blue, they are knock-out beautiful. Bright hot colors, such as red, orange and yellow are available in short compact bedding plants as well as the tall giant-flowered types. Soft pastels and deep reds and purples are also available in all forms and sizes, so you are sure to find plants to suit your needs. Flower forms are varied, and include anemone, collarette, orchid, peony, single, ball, water lily and cactus. The plants add great pizzazz to a garden.
We love dahlias too because they are wonderful cut flowers, easy to arrange. The largest ones, the so-called dinner plates, are not as accommodating: the stems often can’t support the weight of the flower once cut. I prefer the mid-size to small flowering types with strong stems, and grow as many as I can pack into my garden. In a bouquet, the flowers mix beautifully with other blossoms that come along at the same time, such as Alstroemeria and Baby’s Breath.
We love the plants too because they are easy to grow if a few basic needs are accommodated. Fortunately, they love our climate around the Monterey Bay, giving us a head start. With a fully sunny exposure, rich soil with decent drainage and enough moisture, they produce nonstop from mid-summer until cold weather induces dormancy, especially if you regularly remove spent flowers.
They’ll perform best for you if you give them compost, composted manure and a slow-release organic fertilizer each spring. The bedding types are self-supporting but the larger plants will probably need to be staked, using one or more stakes per plant, carefully placed at planting time to ensure that the tubers aren’t punctured. Loosely tie the plant’s stems to the stakes. (Some experienced dahlia growers prefer upside-down wire tomato cages to support the plants instead of stakes and twine. As the plants grow and fill out, the foliage will usually hide the wire tomato cage.)
Are dahlias drought tolerant? Not really though the more your soil is fortified with humus to retain moisture, the less irrigation the plants will need. This year, my plants have gone into a slightly raised bed that was thoroughly dug in spring and had copious amounts of organic matter added. (That was mostly spent bedding and manure from rabbit hutches – I was lucky to find a free source via Craig’s List.) My plants are on drip irrigation, but I grow them scattered among other flowering plants where they seem to get along just fine with minimal watering.
Are dahlias disease or pest-prone? No but they can be attacked later in the summer by the fungal disease powdery mildew, especially when we have lots of fog. To ensure fungus-free plants, twice a month starting now, I will spray them with Revitalize (an organic treatment that prevents fungal diseases.)
For insect control, Captain Jack’s Dead Bug Brew (approved for organic gardens) works very well, as does a simple soap spray, though insects are usually not a problem. Harvest blossoms regularly through the summer to prevent seed formation; this will keep the plants producing well into the autumn months and allows the gardener to enjoy the flowers in arrangements and to give them away as gifts, as late as the Thanksgiving holiday.
Visit www.dahlia.org for excellent information on how to grow these wonderful flowers.
Garden tips are provided courtesy of horticulturist Sharon Hull of the San Lorenzo Garden Center. Contact her at 831-423-0223.
