You need to love a flower that’s a master of disguise. Dahlias are catchy way — if you would like a flashy bloomer which could look just like a cactus blossom, a waterlily, a peony or an orchid, then dahlias are your thing. With their unbelievable array of colours, sizes and forms, there’s a dahlia for almost any garden. But don’t say I did not warn you: Dahlias are almost embarrassingly flamboyant, so don’t even bother trying to throw them. Give them a point to play and let them make their play — they are divas, after all.
The New York Botanical Garden
Botanical name: Dahlia spp
Common name: Dahlia
USDA zones: 8 to 10 (find your zone)
Water requirement: Typical; consistently moist soil but not soggy
Light requirement: Full sun to light shade
Mature size: 1 foot to 5 feet tall, depending upon variety
advantages and tolerances: Quick growing and heat loving, with colorful blooms; attracts hummingbirds and butterflies
Seasonal attention: Blooms summer into fall
When to plant: Plant in spring, after the threat of frost has passed.
Shown: Dahlia‘All Triumph’
The New York Botanical Garden
Distinguishing attributes. Dahlias feature a blossom per solid stem. These flowers can be as small as 2 inches or as large as 1 foot in diameter (called dinner dishes ); the bigger, taller blossoms need pruning to prevent flopping over. They grow in a huge range of colours, petal formations, shapes and sizes, which makes them a very versatile addition to a lot of gardens.
Shown: Dahlia‘Awaikoe’
Glenna Partridge Garden Design
How to utilize them. Dahlias are perfect for beds, borders, container plantings and cut flower arrangements, and as ground covers. Because of the broad range of heights and sizes, make sure to know the older height of this dahlias you would like to grow to prevent planting a 5-foot giant at the front of your perennial bed.
Dahlias do well with some low-nitrogen fertilizer (5-10-10) within 30 days of planting, and again 30 days later. Don’t overfertilize — with dahlias, fertilizers produce leaves, and decent watering leads to flowering. Gardeners who live in zones colder than zone 8 should cut back the foliage when it has withered in the very first frost, and then dig up and store the tubers on the winter before replanting in the spring. Gardeners in warm climates need to have the ability to leave the tubers from the floor for longer blooms the following year, however, you might also simply treat them as annuals and plant new ones every year.
The New York Botanical Garden
What to Consider. Dahlias do often have their pesky problems — after all, so much gorgeousness can not come without a cost. Be on the lookout for slugs and snails, especially as new plants are emerging in the ground. Use slug bait until the crops are at least a foot tall. Earwigs are another possible problem; they can be controlled with careful use of insecticidal soaps or sprays. Dahlias are susceptible to powdery mildew, which can be treated with a fungicide. To prevent powdery mildew in the first place, consider using drip irrigation at the base of the plant to maintain water away from the foliage.
Shown: Dahlia‘Happy Single Day’
The New York Botanical Garden
Planting notes. Dahlias grow from tubers, that need to be planted in the spring after the danger of frost has passed and the soil has warmed up.
Select a website that’s somewhat bright, with well-drained soil. Dig a hole three times as heavy as the width of the tuber and set the tuber from the hole with the buds facing upright. Cover the tuber with dirt and gently tamp down, watering in thoroughly when the soil is dry. Space the tubers 1 to 3 feet apart, depending on the variety. Be prepared to bet the taller varieties to keep them upright as they grow. Shown: Dahlia‘Ellen Huston’
Lear & Mahoney Landscape Associates
Popular dahlia kinds. These kinds are different only in appearance, not maintenance. Care is consistent from type to type.
Cactus and semicactus: Pointed petals, almost spiky in appearance
Waterlily: Slightly curved petals that have a waterlily appearance
Single: A single disc using a ring of petals encircling it
Anemone: Petals that seem like dense, enlongated tubes
Pompon and ball: Perfect spheres created from inwardly curling petals; the balls have a spiral arrangement to their petals
Collerette: Large petals which form an outer ring around a central disc, using a circle of much smaller petals in the Middle
Decorative: Broad petals without a fundamental disk
Miscellaneous: Blooms that resemble orchids and peonies