All summer long, ponds in the Rogue Valley offer more than soothing sounds and cooling waters. They've got flowers! Our climate is just right for many blooming water plants, and it's even possible to have a full year of blooms. Many of the stellar bloomers that thrive in our summers originate in the tropics, and can't survive our winters. But with a small amount of preventative care, even these torrid beauties can bloom year after year.
Nurseries have good selections in water plants now, says Dennis Trost, co-owner of Southern Oregon Nursery's new shop, In Thee Garden. For vibrant color, he suggests tropical waterlilies (Nymphaea). These plants offer pond gardeners a literal rainbow of vivid colors: red, pink, white, yellow, blue, purple and, yes, green. Included among the hundreds of available varieties is the unusual 'Green Smoke,' with blooms that are lime green trimmed with white.
Don't worry if your new pond gets murky right away. Medford Grange Co-op customer advisor Esther Lee says all new ponds need to go through a transition stage, which means cloudy water for a while.
It takes six weeks to two months before the algae growth cycle balances out, she says. In the early stages of a new pond, unfavorable algae grow along with more favorable ones. If pond gardeners keep scrubbing their rocks to clear the waters, the good algae and the bacteria they support won't get a chance to gain dominance. It's the process you have to support, says Lee.
"After you get the balance, pond care is easy," she says, so forget about having crystal clear water in your new pond.
Another must is to include rocks in the pond. They help modify the extremes of daily temperature, especially common in the Rogue Valley's spring and early summer. The rocks hold heat and transfer it to the water. According to Lee, the modulation of temperature favors a balanced ecosystem.
These plants have a great scent as well, says Esther Lee, customer advisor at Medford's Grange Co-op. "Even just walking by, you will notice their fragrance." Best of all, they bloom all summer.
Tropical water lilies are usually under $20 and worth the price even when you treat them as an annual, says Trost. With some extra care, they can last over the winter. Remove them from the pond before the first frost, says Lee. Clean off the roots and put in a canning jar or paper bag. Store the dormant roots in a greenhouse, a cool pantry or even under the sink at about 45 degrees. In May, soak the roots thoroughly in water, then repot. Sprouts will begin to emerge, but don't put them back into the pond until Mother's Day, when the danger of frost is past.
Another water plant that blooms all summer is lotus. The Buddhist symbol for enlightenment, this plant requires at least a half day of sun to produce its familiar pink (or white or yellow) flowers. Morning sun is best, Lee says. Without any shade or with western exposure, you may notice some browning of their floating leaves, but blooming will continue unabated. These plants will winter over, but need fertilizing now.
"Most pond plants should have annual fertilizer, especially when they stay in their containers," says Trost.
Canna plants, which can be grown in bog or pond conditions, provide lots of color at the end of the season, especially the tropical colored varieties of canna. To keep these plants for another year, remove them from the pond before first frost. Leaving them in their pots, cut back the stalks and either heel into soil, bury the pots in a pile of leaves or stash them under a bush. They can be taken out in spring, fertilized and when growth reaches about 4 to 6 inches, returned to the water, says Lee.
Most of these plants bloom from containers, so make sure they don't become root-bound, warns Trost. Since you'll be handling your plants in spring, repot any with cracked or distorted pots. In summer you can spot root-bound specimens by their less-than-healthy color or failure to bloom. Split the plants into two containers, add potting soil and place back into the pond.
Both our experts recommend keeping at least 60 percent of the pond surface covered with floating plants during the summer. This minimizes the algae problems that occur as water temperature rises. Lee says up to 70 percent of the surface can be covered, keeping water temperature down and providing more cover for fish. Most attractive of all, less algae means you have fewer chores to do.
So, plant, fertilize, and sit back to enjoy the scent, sight and sound of your water garden.