Dahlia Care Guide: How to Care for Dahlias + Growing Tips

Dahlia flowers are a symbol of grace and kindness that make for beautiful additions to any garden or home. There are plenty of varieties to choose from, so you are sure to find a dahlia that appeals to you. With a few simple tips in mind, caring for these unique spring flowers are a breeze, especially in the summertime!

Below we’ll cover proper dahlia care, including sun, water, temperature and other care needs so you can begin nurturing your dahlias. We’ve also included different types of dahlias, some frequently asked care questions and a bonus section on dahlia bouquet care.

Dahlia Overview

Dahlias were first recorded by Westerners in 1615 and were originally called by their Mexican flower name Acoctli. They’re native to many parts of Mexico and Central America, so it’s not uncommon to find them thriving in warmer climates. These flowers are considered mid-to-late season blooms that peak between summer to just before the first frost. 

There are 42 types of dahlias within 14 groups that all differ from each other in shape and size. Many dahlia flowers are either single- or double-flowered — single blooms have a defined center bordered by only a few rows of outer petals. Double-flowering types, on the other hand, have multiple rows of petals with no visible center. 

Known for their unique petal arrangements, dahlias are considered by many professional gardeners as one of the most attractive and requested flowers. In fact, their beauty goes all the way back in history to when Queen Victoria was alive, who claimed dahlias as one of her favorite flowers alongside violets. Though these vivid blooms are relatively easy to grow, they have proven to be temperamental with weather and sunlight, so be wary when first starting out.

Types of Dahlias 

There are over 42 types and varieties of dahlias that range in size, color and texture. While widely known for their vivid colors and tightly grouped florets, there are varieties that have different and unique shapes to fit any garden aesthetic. Below are some of the most popular dahlia flower varieties.

Decorative

As the largest category of dahlias, it comes as no surprise that these gorgeous blooms can be found in a wide variety of shapes and colors. Decorative dahlias can be either formal or informal — formal flowers have evenly placed petals while informal ones have flat petals that are irregularly placed.

Pompon

Pompon dahlias are a beautiful and unique sight — these globe-shaped flowers have small petals that are usually slightly rounded at the tips and perfectly arranged around the stem. These delicate blooms reach a maximum of two inches in diameter.

Cactus

These dramatic and stunning flowers can be spotted from a mile away due to their spiky petals! Cactus dahlias are double-flowering and come in a range of sizes and colors — their long, rolled petals are perfect for someone who wants an eye-catching flower in their garden.

Collarettes

These distinct blooms feature large, flat petals that surround a ring of shorter petals. The smaller petals are often a different color, forming a collar in the middle of the bloom, making them a beautiful addition to any garden.

A few other popular varieties of dahlias include: 

Peony: These single-flowering blooms have open centers and come in a variety of colors. The petals are often irregularly formed, giving the bloom a fluffy and textured look.

Orchid: Unlike the orchid flower, this type of dahlia has an open center and long petals. It can either be a single orchid, featuring one row of petals or a double orchid, with two rows of petals. 

Anemone-flowered: These stunning blooms have an outer ring of flat petals surrounded by a dense group of long and tubular petals. They come in bright and vivid colors, making them the perfect choice for any bouquet.

Water lily: These pink flowers have double blooms made up of broad and sparse petals. They’re known for their striking colors and patterns, making it quite an eye-catching bloom!

How to Care for Dahlias

Dahlias are lovely spring and summer flowers that are moderately easy to grow and perfect for those who want a colorful addition to their garden. However, they are sensitive to cold temperatures and require full sunlight so it’s important to keep a close eye on them, especially in the early stages of growth. 

Sunlight 

Dahlias require at least six to eight hours of full sunlight a day. If you live in a hotter climate, be sure to place them in a partially shaded area during peak afternoon hours to avoid burning the plant.

Water

Dahlias, unlike many other flowers, do not require a lot of water. If you live in an area where there’s summer rainfall, that usually is enough for the plant to survive. Otherwise, water deeply once or twice a week. You’ll want to make sure that the soil is always moist — if you notice that the top layer is dry, that’s a sign that the plant is in need of water. 

Temperature

Soil temperature is key to the healthy growth of dahlias. Be sure to plant these flowers in ground temperatures of 60°F or warmer (you can check with a metal thermometer). Keep in mind that dahlias tend to struggle in cold soil (less than 50°F) so you’ll want to wait until spring or early summer to plant them. 

Toxicity

Though dahlias are not severely toxic to pets, you’ll still want to keep these blooms away from your furry friends as they can cause unpleasant symptoms like vomiting and diarrhea. If you plan on planting your dahlias in the garden or keeping them in a vase, be mindful about placement if you have a curious pet at home. 

Pests & Problems

Pests: Dahlias tend to attract earwigs, thrips and caterpillars. They also are a delicacy for slugs, who like to feed on dahlias when the plant is young and small. If you have a slug problem, you may want to reconsider planting dahlias or find a new spot for them that is slug-free. 

Problems: Like many plants, dahlias are prone to fungal diseases, including powdery mildew which is common in warm and dry climates. This can be identified when your plant has white, dusty splotches of powder on the leaves. To treat this, you can do one of two things: trim off the infected portions of the plant or apply a fungicide. 

Repotting & Propagation

Repotting: Repotting dahlia tubers (thickened, underground part of the stem) should be done in early spring, about eight weeks before the last frost. This gives the plant a head start, allowing it to develop full, healthy blooms by summertime. 

Propagation: Dahlias can be propagated from seeds, tubers, or cuttings. If you choose to propagate with cuttings, be sure to snip off the lowest set of leaves and stick them in a pot of soil with good drainage. Keep the pot warm and moist and you’ll begin to see the cutting take root within a few weeks.

Now that you know the basics, it’s time to cover a few more tips and questions that will make your growing process even easier!

Dahlia FAQs

While dahlias are relatively easy to take care of, you may still encounter some problems or have questions about how to raise them. Below are some common questions about dahlia flower care and their life cycle.

Can you leave dahlias in the ground over winter?

Since dahlias are warm weather plants, they cannot tolerate cold temperatures. However, though everything above ground may die during the winter, the bulbs will stay warm underground. If you live in weather below 20°F, you may leave the tubers in the ground — just be sure to cut back the plants to several inches above soil level. If you live in a climate where winters are above 20°F, your flowers may survive with proper dahlia winter care. 

How do you keep dahlias blooming?

Keeping your dahlias in a spot that gets full sunlight is ideal, though partially shaded spots can also nurture dahlia blooms. They prefer rich and well-drained soil, however, keep in mind that the soil should be evenly moist, but not excessively wet, or the roots may rot.

Do dahlias come back year after year?

Yes, since dahlias are perennials, they are able to resprout from their underground tubers to bloom in the summertime every year. If you live in a warm climate, the chances of dahlias coming back are even greater.

Dahlia Bouquet Care Tips

Not only do dahlias make a wonderful addition to any garden, but they also make for gorgeous bouquets in the spring and summer! Below are some tips to ensure you get the most out of your beautiful floral arrangement.

Trim the Stems 

After freshly cutting the dahlias from your garden, get a pair of sharp scissors or a knife and cut off one inch from their stems. Be sure to do this at an angle, as this allows the plant to absorb more water. 

Arrange Dahlias in a Vase

Once you trim the stems, place the flowers in a vase shape of your choice filled with warm water (about 110°F). This prolongs the life of the flowers and allows the water to flow in the stems quicker. Don’t forget to trim any leaves or buds that will be submerged underwater as that could shorten the dahlias’ vase life. 

Keep Flowers Cool

Before you place the flowers on display for all to admire, you’ll want to keep them in a cool place for one or two hours. The cooler temperatures will allow the flowers to quickly absorb the water and any floral preservatives you use without the harshness of sunlight. 

Replace Water

Check the water frequently (about once a day) and replenish when needed. Remember to recut the stems at an angle every two to three days to ensure the flowers are absorbing enough water. 

Whether you choose to grow decorative dahlias or pompons, you’ll surely be in for a treat with this gorgeous spring flower. Dahlias are a must in any garden and are perfect for all experience levels. With a few of our tips in your back pocket, you’ll be mastering the basics of dahlia care and will become an expert in no time!