Dahlias are truly stunning perennials in any sized flower garden. Their bushy forms fill borders, containers, and fence lines with mid- to dark green feathery foliage. The green contrasts nicely with dahlias’ outstanding blooms. Flowers delight in a broad spectrum of bright and pastel colors. The diameter of those happy blooms range in size from a petite two inches up to a full ten inches.
Dahlias are native to Mexico and Central America. This heritage gives them a wildflower-like appearance and disposition. Depending on variety, dahlias are hardy to US Department of Agriculture Hardiness Zone three though most varieties will feel most at home in warmer climates similar to their native climate. In many regions throughout the US, dahlias are grown as annuals.
Some dahlia plants can grow to a very large height of up to 10 feet tall while some smaller dahlia varieties fit comfortably in a pot on a patio. Underneath dahlias lovely limbs lies a well kept secret. Dahlias’ tubers are not only edible, but they are said to be enjoyably tasty. If you’re looking for an edible tuber, do your research. Make sure the dahlia is for food production and NOT an ornamental bulb. Ornamental bulbs / tubers are often treated with chemicals.
Dahlias were once such a valuable food source that an East Coast Native American tribe cultivated a red double-flowering dahlia plant for 400 years only for the tubers. Recently, this particular variety of dahlia has been preserved and protected as an heirloom root vegetable. The comeback of these edibles has made for a light-hearted tiff amongst some gardeners. A few dahlia flower gardeners have questioned the good sense of those gardeners who would dare harvest dahlias for the tubers at the loss of those irresistibly captivating blooms.
How to Grow and Care for Dahlias
Dahlias will grow from seed, but they are most often grown from division. Dahlia tubers can be purchased online and at local nurseries. Once you’ve selected your favorite dahlias to plant, thoughtfully consider where you’ll grow them. Dahlias are easy to cultivate – especially when you honor their simple needs.
Dahlias love the sun, so plan a spot where they’ll receive plenty. They’ll grow best in rich, well-draining soil. And they love water, so make sure your dahlias get enough of it. When do you plant dahlias? You’ll want to plant your dahlia tubers in the spring after your last local frost date. You can figure out your local planting time here.
Dahlias will enjoy an early summer boost of nitrogen rich fertilizer followed by weekly feedings of potassium rich plant food beginning in the mid-summer season. These treats are a sure fire way to keep those blossoms bursting.
And speaking of blooming, you can expect to enjoy dahlias happy blooms from mid- summer until the first frost. Besides fertilizer, dahlias will produce the most flowers if you dead head. To dead head dahlias properly, don’t just pop the spent flower heads off of the stem. Track the spent flower stem down to the point where it meets the main plant. You might notice a little nodule just waiting to spring forth. It will – as soon as you cut the spent stem back just above that nodule.
Enjoy the long lasting blooms either on the plant outdoors or in a vase indoors. Dahlias make excellent single cut flowers or cut flower arrangements.
If growing in gardening zone 8, leave the tubers in the ground for the winter. In other more severe climates, gardeners should consider digging up the tubers to overwinter.
Dahlia Pests, Diseases, and Problems
In spite of a spunky disposition, they do have a few weaknesses. Pests that dahlias find particularly troublesome include slugs, snails, caterpillars, and spider mites. Diseases include powdery mildew, fungal leaf spots, and soft rot.
Many of these pest and disease problems can be thwarted with careful watering methods and proper spacing for good air circulation. And, dahlias play well with several plants such as white geraniums and salvia. Not only will these companion plants complement your dahlias’ beauty, they will fight off some of the pests that tend to bother dahlias.
With dahlias’ wide range of plant and flower shape and size, there’s undoubtedly at least one dahlia or another to appeal to every flower gardener’s fancy. Here are a few noteworthy varieties to pique your interest in dahlias.
‘Fire Pot’ dahlia is a hardy, easy to grow cultivar. With bright pink and yellow flowers that resemble a water lily, this alluring eye catcher will bloom and brighten up your garden and your day.
‘Honka’ is one of the simplest dahlia flower types. With single, flat, petals this dahlia resembles a yellow star against its dark green foliage. ‘Honka’ is a warm weather friend.
‘Kidd’s Climax’ sports an astounding pink blended with yellow bloom that’s the size of a dinner plate. Butterflies can’t resist this dahlia’s happy face, and neither will you.
Quick Dahlia Questions and Answers
How do you take care of dahlias?
You’ll want to plant your dahlia tubers in rich, fertile soil in a spot that gets full sun. Keep them well watered, and you should see growth and can watch the flowers bloom from summer until the first frost.
Can you leave dahlias in the ground in winter?
Yes, you can leave dahlias in the ground in the winter, as long as the tubers are covered up well enough in the garden bed. Covering your bed with a layer of mulch or compost will help keep them warm enough.
Do dahlias do well in pots?
Yes, you can successfully grow dahlias in pots as long as your container is big enough. You should try a container that is at least 12 inches in diameter and also has at least 8 to 12 inches of depth so that the tubers have enough room.
How do I store dahlias over winter?
Take the tubers of your dahlias out of the ground after the first frost, and store them in a cool, dark place like in a wooden box. You can store them sitting on peatmoss, or perlite. If you have someplace like a pantry that won’t freeze, you can even do something as simple as storing them in a paper bag by themselves.
When to plant dahlia tubers?
Plant them in the spring, after your last frost date.
Are dahlias annuals or perennials?
Dahlias are perennials, and will come back each year on their own if they are in a warm enough area of the United States. However, in colder gardening zones, gardeners grow them like annuals. So it really depends on where you are located!
Do dahlias come back?
If you are in a warm enough zone, then dahlias will come back the next year. Dahlias are native to Mexico and Central America. If you are in a zone that is too cold, then you’ll need to dig up the tubers after the first frost and then plant dahlias again the following spring’s last frost to keep them around.
When to dig up dahlias?
If you live in an area where it is cold enough that the tubers need to be dug up, then you’ll dig them up after the first frost. If you live in a warm part of the country, you probably don’t need to dig them up at all.