Complete Indoor Care for Dahlias


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Indoor care for Dahlias can become problematic for a relatively new gardener. Due to the environment dahlias need to grow, they should not be indoors year-round. It is best to start growing them indoors and then move them outdoors when they’ve had time to mature.

If you plan on keeping your dahlia indoors year-round, you should do your best to mimic the conditions it would receive outside. Try to master the temperature, humidity levels, watering needs, soil requirements, and all of the essentials to help a Dahlia thrive indoors. In this article, you’ll find everything you need to grow your dahlia to its full potential.

Before Getting Started with Indoor Care for Dahlias

Before you even bring a dahlia home, do your research on their care requirements to ensure they are a good fit for your living conditions and everyday schedule. Aside from putting in the research, grab the necessary tools. A nice size container, potting mix, handheld shovel, gloves, watering can grow light, and maybe even a humidity tray could be beneficial to have on hand before getting started.

Choose the Right Pot

Before learning how to care for your dahlia correctly, you must pick out the correct pot for your plant. Dahlias sprout from buds formed on tubers, and those tubers need to fit comfortably in there when planting. It is best to choose a pot with a wide diameter, preferably between 8 and 12 inches, depending on the size of the tubers. Try to match the depth of the dahlias pot to the potential height of the plant to ensure it doesn’t look too small or too big for it when fully grown.

The container you choose to use should also have plenty of drainage holes. In the early stages of growth, the tubers are susceptible to rotting if the soil stays wet. If there aren’t enough drainage holes in your container, or none at all, drill a couple and ensure you use a well-draining potting mix to prevent rot.

Before you begin potting, clean your container thoroughly. Even if you bought your container new from the store but especially if you are reusing an old planter from the garden, it should be cleaned and rinsed with soap and water. Dirty pots can harbor bacteria and spread disease to a newly potted plant, causing problems before they have a chance to grow.

Starting Indoor Care for Dahlias

The best time to plant your indoor dahlias is in early spring, six to eight weeks before you plan to move them outdoors. Starting your dahlia as an indoor potted plant will encourage earlier blooms. Of course, you can wait until after the last expected frost and plant your dahlias directly in the ground or into your outdoor decorative pot, but your plant’s blooms will not last long if you do this.

If you plan to start your dahlias indoors, use a one-gallon pot to give the plant’s roots plenty of room to grow. Be sure the container you start in has drainage holes to prevent overwatering and root rot. Start by filling the pot with well-draining garden soil that is moist but not soggy. Then plant one tuber per pot on its side, about two to three inches deep.

Lastly, place your container of choice in a warm, sunny spot (at least 60 degrees), and don’t water until the sprout shows above the soil. Should your indoor space allow, you can also plant your tubers directly into the decorative containers you plan to display them in once outdoors. Just make sure to keep it inside until after the last expected frost.

Indoor Care for Dahlias: The Basics

It is crucial to care for your dahlia correctly. To ensure the best growth for indoor plants, do your best to mimic the outside environment that this plant would commonly thrive. 

How Often to Fertilize Your Dahlias?

Luckily dahlias are not demanding, but a balanced fertilizer is recommended (10-10-10 or 15-15-15), and feeding your dahlia once per year is preferred. If using a lower strength fertilizer, you may want to fertilize your plant twice a year if it looks like it needs it. Hungry dahlias typically look like their leaves are yellowing.

Indoor Care for Dahlias: Watering

As with most plants, watering amounts and frequency vary depending on soil, weather, and plant size. When dealing with tubers, you should only water the plant after seeing it sprout above the potting soil. After that, water about two times a week, allowing the soil to dry out before watering again. Near the end of the season, when the weather is the hottest, you can increase watering since the potting soil will dry quickly.

Adult dahlia plants prefer moist soil. Unfortunately, gardeners new to dahlias may understand that to mean the plant likes moist soil all year round, which can result in the demise of your precious plants before they get the chance to a single leaf. The plant’s food source – the tuber – will rot if the soil remains moist for too long.

Avoid overwatering dahlias in the early stages of growth. Allow the soil to dry out completely before your next watering. Once the plant has matured and, the container is full of potting soil, you can begin watering regularly.


While not essential, pinching at the right time will make your dahlia plant bushier, more robust, and allow it to produce more flowers. When it comes to dahlias, more flowers are always the goal. When the plant is displaying four sets of leaves, locate the highest sprout in the center of the plant. Remove the dahlia sprout with scissors, ensuring you don’t damage any nearby stalks or leaves.

Pinching will encourage the plant to produce more stems laterally. If you want the plant to branch further out, you can pinch the tips of new stems once more to grow more lateral branches. If you desire to see your blooms quickly, you may want to skip the pinching step. Redirecting the plant’s energy towards producing new stems will detract from the flower production process briefly. You may delay flowering by one or two weeks, but you will have more flowers as a result.

Deadheading as Part of Indoor Care for Dahlias

Deadheading is the practice of removing spent flowers from the plant. It is essential in any flower garden. If you want as many flowers from your dahlia plant as possible, deadheading is the way to go. By removing the flowers that are past their prime, you keep the plant tidy, and it can use all its energy on making new flowers – not keeping old ones alive.

To deadhead your dahlias, remove any spent flower heads with scissors or with your fingers carefully to ensure you do not damage any nearby stalks or flowers in the process. You can also cut the stems back to the main branch to facilitate the growth of new stems and new flowers.

Indoor Care for Dahlias – The Wrap-up

Growing dahlias in containers can be difficult for beginner gardeners, but it doesn’t have to be. However, dahlia indoor care can be trickier as the indoor environment is quite different from the outdoors.

If you plan on keeping them inside year-round, it is best to mimic the outside environment. You may have to use a growth light and give your plant natural sunlight to accommodate the lack of indoor sunlight. It may also be beneficial to use a humidifier or dehumidifier to create the perfect environment indoors. Whether you plan to keep it inside or move it outside, it is best to start the initial growing process of your plant inside.


Dahlias are easy to grow and yield beautiful blooms from mid-summer through fall. In many respects, “dahlia culture” is similar to “tomato culture.” If you can grow tomatoes in your garden, you can successfully grow dahlias.

Dahlias are mostly fragrance-free; though they have been successful with a couple of hybrid creations, the majority of dahlia blooms smell like nothing at all.

Nowadays, Dahlia is widely used even for economic purposes: in landscaping, in floristry as a cut flower, for the pharmaceutical industry, cosmetic, food, and as raw material for the extraction of dyes. Both the tuberous roots and the flowers of this ornamental and medicinal plant are used for therapeutic purposes.

Dahlias are tuberous perennials, and most have simple leaves that are segmented and toothed or cut. The compound flowers may be white, yellow, red, or purple in color. Wild species of dahlias have both disk and ray flowers in the flowering heads.

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 —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.


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