Dahlias: Info and Care

Dahlias: Information and Care

Dahlias, named for the eighteenth-century Swedish botanist Anders Dahl, is a genus of tuberous perennial flowers. Native to Mexico and Central America, they are popularly grown for their blossoms that range in shapes, sizes, and colors.

Some varieties open and puff out, producing rotund orbs with folds of petals While others develop massive round disc-like blossoms, resembling sunflowers.

After all, sunflowers, daisies, and chrysanthemums are relatives of dahlias. The whole plant typically grows to be 4-5 feet tall. Dahlias are best suited to wet and temperate climates; they may not thrive in extremely hot locations.

If your growing season is at least 4 months long and isn’t excessively warm, you’ll be able to enjoy the bright and cheery blooms in your own garden. 

Dahlia Growing Details

Dahlias Flower Care

Dahlias are tender perennials that should be dug up every Winter in cold climates to avoid frost damage. They will have a difficult time getting established in cold soil. In the Spring, let the earth warm up to 60 degrees before planting.

After all danger of frost has passed, plant them when you would other tender plants, like tomatoes and peppers. Some varieties may benefit from getting a head start, planted in containers a month before being transplanted outside. 

Planting Site

Choose a site that receives full sun and has some shelter from the wind. Ensure they will receive 6 to 8 hours of sun per day. Plenty of early morning sun is ideal for perky blossoms. Rich, well-drained soil will provide the right conditions for the tubers.

The optimal soil pH would be slightly acidic, 6.5-7. Medium and smaller-sized dahlias mix well and can be planted among other flowers and vegetables. For larger varieties, assign an exclusive place and arrange them in rows. They can dominate the space without having to compete and can be cared for more easily. 

RELATED: Best Dahlias For Cut Flowers

Establishing Dahlia Tubers

Prepare tubers for planting by first inspecting them. Discard any that are shriveled or show signs of rot. Do not split apart individual tubers. Pink or green buds are good signs of vitality. Allow 2 feet of space between small varieties and 3 feet between large variety plantings. Dig a hole slightly larger than the root ball and incorporate some compost or bone meal when planting.

Set tubers with buds facing up and cover with about 3 inches of soil. Withhold water until sprouts appear above the soil surface. Expect blooming to commence in about 8 weeks during midsummer. Mulch may be counterproductive, attracting slugs and depriving the roots of the sun’s warmth.  

Maintenance & Care

Dahlias Info and Care

Dahlias should receive a deep watering, 2 to 3 times per week. Overwatering can lead to rotten tubers. Feed with a low nitrogen fertilizer after they sprout and then monthly throughout the season. Pinch out the main leading stem when it reaches a foot tall. This encourages a sturdier, bushy plant with more blooms.

To maintain smaller varieties, pinch out leaders and deadhead throughout the season.

Taller varieties will require support and more detailed maintenance. Install a stake for each tuber at the time of planting. Pinch and prune as needed. Remove small side buds to promote large prominent flower heads. Deadhead accordingly to encourage a longer blooming season. 

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Winter Care & Storage

Tubers can be left in the ground year-round in warmer climates. Cut them to the ground after the first frost and use a heavy, dry mulch to insulate them from the cold weather, don’t let them freeze in the ground.

In colder northern regions, tubers should be dug up and stored for winter. After the frost and cut down, use a fork or shovel to gently loosen the soil around the tuber.

Carefully remove tubers and rinse off all soil with a hose or in a tub of water. Let them dry and cure for a couple of days. Store tubers in cool temperatures, below 50 degrees, in cardboard boxes or plastic bags. Sand, wood shavings, and styrofoam will allow airflow and retain moisture around the tubers. 

Dahlia blossoms will brighten up any garden space, their beautiful flowers are attractive and inviting. They are easy to care for and practical. No need to purchase new plants year after year. Whatever style or look you prefer, there will be a dahlia that fits your ideal of elegance. 

RELATED: Dahlia Pacific Ocean

Life is Better When You Garden™

Do dahlias come back year after year?

If you live in the USA climate zone 8 to 11, you can leave your dahlias in the ground to overwinter. Dahlias grow from the tuberous root prone to rot from excessive moisture and low temperatures. You should dig tubers in the fall and store them in a cold, frost-free area. Then plant them next spring, when the danger of the last frost passes.

Do dahlias like sun or shade?

Like roses, dahlias are more beautiful and lush if they grow exposed to a lot of sunshine. They need at least 6 hours of direct sunlight each day to develop complete form and lush blooms. If the dahlia grows in a shady place, it will bloom much later, giving only a few underdeveloped flowers for the whole season.

Are dahlias hard to grow?

Dahlias are popular garden plants not only because of their magnificent flowers but also because of their simple cultivation. Planting them after the danger of late spring frosts or starting them indoors in early spring will provide a long-lasting flower festival until late autumn. Yet, these are plants for diligent gardeners as they need to be dug up and stored after each season.

Where is the best place to plant dahlias?

For planting dahlias, choose the sunniest part of the yard or garden with nutritious and well-drained soil in which the water will not stay too long. Dahlias will feel at home, where many other flowering plants suffer from the blazing sun!

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