Dahlias are trending big time, with an increasing number of green thumbs adopting them for their spectacular summer blossoms. However, a few simple growing blunders can lead to a lack of flowers and even wipe out your plants, warns Julie Williams, co-owner of Stonehouse Dahlias and a seasoned dahlia cultivator with over two decades of experience. Here, she reveals the typical pitfalls that gardeners encounter with dahlias and how to address them right away.
Julie Williams, along with her business, Stonehouse Dahlias based in Utah, is a leading online provider of unique dahlia varieties.
Many enthusiasts like to kick off the summer by starting dahlias in pots indoors before moving them outdoors. But Williams cautions against delaying this process too long. “Most windowsills don’t offer the necessary sunlight for dahlias, which can result in leggy, weak plants,” she points out.
The Solution: Transplant your dahlia室外 as soon as the risk of frost has vanished. If you’ve missed that opportunity, don’t stress: “If your plant has become stretched from being inside too long, plant it deep, covering some leaf nodes,” Williams suggests. “Each node you bury will grow new roots, bolstering the plant’s strength.”
Dahlias can be propagated from tubers or cuttings, but these two methods require different watering regimens, which can lead to issues if they’re all watered uniformly in the same plot. “Overwatered tubers are susceptible to rot, while under-watered cuttings may shrivel and die,” explains Williams.
The Solution: If possible, keep your tubers and cuttings in distinct locations. Wait to water tubers until you notice growth emerging from the soil. For the first couple of weeks, water cuttings frequently, and they’ll also benefit from some fertilizer for additional nourishment.
It might seem odd to meddle with a dahlia’s natural progression, but “left unchecked, dahlia plants have a tendency to grow tall and spindly, with few branches or flowers,” according to Williams.
The Solution: Once a plant reaches about a foot in height, trim it just above the topmost leaf cluster, a process known as topping. Even if you’ve missed this timing and your plant is taller, it’s still补救able. “Removing the central shoot prompts the plant to branch out,” Williams clarifies. “Instead of a single growth point, you’ll get multiple side shoots, all capable of producing flowers.”
When dahlias are just small sprouts, it’s tough to envision their eventual size, especially for first-timers. However, neglecting to stake them can result in droopy plants, or even worse, damage from the elements. “Dahlias are fragile and can snap or tip over in a strong breeze,” Williams says. “Many gardeners lose their cherished dahlias during windy weather.”
The Solution: Even if your dahlia has already shot up a couple of feet, it’s not too late to stake it. Williams advises placing a sturdy stake near the plant and securing the stem to it with twine at intervals of about a foot or two. (If you’ve grown your dahlia from a tuber, be careful not to position the stake so close that you accidentally puncture the tuber.) Alternatively, she suggests using a tomato cage to support the plant.
