Table of Contents
- Introduction
- The Best Time to Buy Dahlia Tubers
- Understanding the Shipping Schedule
- Why Soil Temperature Matters More Than the Calendar
- What to Look for When Your Tubers Arrive
- Storing Your Tubers Before Planting
- Planning Your Dahlia Garden Layout
- How to Plant Your Dahlias for Success
- Popular Varieties to Look For
- Caring for Your Dahlias Through the Season
- Troubleshooting Common Timing Issues
- Dahlias: A Rewarding Long-Term Investment
- Conclusion
- FAQ
Introduction
Choosing your dahlia colors is one of the most exciting parts of planning a summer garden. These spectacular flowers offer an incredible range of shapes and sizes, from delicate pompons to massive dinnerplate dahlias. At Longfield Gardens, we see how much joy these blooms bring to a landscape, and we want to help you time your purchases perfectly to ensure a successful season.
Knowing exactly when to buy dahlia tubers is the first step toward a garden filled with vibrant, late-summer color. This guide is for home gardeners who want to understand the seasonal buying cycle, from pre-ordering in the winter to late-spring planting. We will cover how the shipping schedule works, what to look for in a healthy tuber, and how to care for your tubers until the weather is just right for planting.
The key to a beautiful dahlia garden is getting the timing right so you can secure the best varieties before they sell out.
The Best Time to Buy Dahlia Tubers
The best time to buy dahlia tubers is in the late winter and early spring, specifically between January and March. While you cannot plant them outside during these months in most of the United States, this is when the selection is at its peak.
Most reputable retailers and specialty growers open their online shops for pre-orders during this window. If you have your heart set on a specific, popular variety like Café au Lait or 'Labyrinth,' waiting until May or June to start shopping often means missing out. By ordering early, you are essentially "reserving" your favorite varieties while the inventory is still full.
The Advantage of Pre-Ordering
Pre-ordering allows you to plan your garden beds with precision. You can take your time browsing through decorative, cactus dahlias and border dahlias to find the perfect color palette. When you buy early, the company holds your tubers in a temperature-controlled environment and ships them to you at the correct time for your local climate. This takes the guesswork out of the process and ensures your plants don't arrive while the ground is still frozen.
Late Season Buying
If you miss the early window, you can still buy dahlia tubers in April and May. While some of the rarest varieties might be gone, there are usually plenty of beautiful options available, including favorites like Labyrinth. Buying later in the spring can sometimes result in finding great deals, but the trade-off is a more limited selection. We recommend aiming for the February or March window for the best balance of availability and variety.
Understanding the Shipping Schedule
Even if you buy your tubers in the middle of January, you won't see them on your doorstep the next day. Reputable suppliers, including us, follow a shipping schedule based on the Hardiness Zone Map. This is done for the safety of the plant.
Protection from Freezing
Dahlia tubers are fleshy and contain a lot of water. This makes them very sensitive to freezing temperatures. If they were shipped in the dead of winter to a cold climate, they could easily freeze in the delivery truck or on your porch. To prevent this, we wait until the weather has moderated enough to ensure the tubers stay healthy and firm during transit.
Arrival Near Planting Time
Typically, orders are scheduled to arrive about two weeks before the ideal planting time for your specific region. This gives you a little bit of time to inspect your order and prepare your garden beds without having to store the tubers for too long. If you live in a warmer southern zone, your tubers will arrive much earlier than if you live in a northern state.
Key Takeaway: Buying and shipping are two different events. Buy early to get the best selection, and trust the shipping schedule to deliver your plants when it is safe to handle them.
Why Soil Temperature Matters More Than the Calendar
One of the most important lessons in gardening is that the soil temperature is a better guide than the date on the calendar. This is especially true for dahlias. These plants are native to Mexico and Central America, meaning they thrive in warmth and struggle in cold, damp conditions.
The 60°F Rule
You should aim to plant your dahlia tubers when the soil temperature consistently reaches about 60°F. If you plant them too early in cold, wet soil, the tubers are likely to sit dormant and may even rot before they have a chance to grow. Waiting for the soil to warm up actually helps the plant grow faster. A tuber planted in warm soil in late May will often catch up to and surpass a tuber planted in cold soil in April.
Checking Frost Dates
In addition to soil temperature, you must wait until all danger of frost has passed. Dahlias are very sensitive to frost; even a light freeze can damage the new green shoots as they emerge from the ground. Check your local extension service or a reliable weather app for the "average last frost date" in your area. Use this as your starting point for getting the garden ready.
What to Look for When Your Tubers Arrive
When your package arrives, it is important to open it immediately. Your tubers have been traveling in a dark box, and they need some fresh air.
Inspecting for Quality
A healthy dahlia tuber should feel firm, similar to a fresh potato. It is normal for them to have some loose skin or to look a bit dusty from the packing material, such as peat moss or wood shavings. At Longfield Gardens, we stand behind the quality of our plants and offer a 100% quality guarantee. If you notice any issues with damage or quality, it is best to contact us promptly so we can help.
The "Eye" of the Tuber
Every dahlia tuber needs an "eye" to grow. The eye is a small growth point located on the "neck" of the tuber, where it connects to the old stem. For a closer look at tuber anatomy, see Are Dahlias Bulbs or Tubers?. These can be very hard to see when the tuber is dormant. They look like a tiny, slightly raised bump or a small pinkish sprout. Don't worry if you can't see them right away—once the tuber feels the warmth of the soil, the eye will begin to swell and sprout.
Broken Tubers
Sometimes a tuber might have a small "dangling" piece or a broken end. As long as the neck and the eye are intact, the plant will grow just fine. The main body of the tuber is simply a storage tank for energy. If a piece is completely broken off and has no eye, it won't grow into a new plant, but the main tuber will still have plenty of energy to fuel a beautiful bloom.
Storing Your Tubers Before Planting
If your tubers arrive but the ground is still too cold or wet to plant, you will need to store them for a few weeks. The goal is to keep them dormant and prevent them from drying out or sprouting too early.
- Keep them cool: A temperature between 40°F and 50°F is ideal. A cool basement or an unheated garage (as long as it doesn't freeze) works well.
- Keep them dark: Light encourages sprouting. Keep the tubers in their original packaging or a paper bag to block out light.
- Maintain moisture: You don't want the tubers to get wet, but you don't want them to turn into shriveled raisins either. Keeping them in slightly damp peat moss or the wood shavings they arrived in will maintain just enough humidity.
- Check on them: Give them a quick look once a week. If you see any signs of mold, increase the airflow. If they look very shriveled, you can lightly mist the packing material with a tiny bit of water.
Planning Your Dahlia Garden Layout
Since you are buying your tubers months before they go into the ground, use that time to plan your layout. This ensures you buy the right amount of tubers for the space you have.
Height and Spacing
Dahlias vary greatly in height. Border varieties might only grow 12 to 18 inches tall, making them perfect for the front of a bed or in containers. Dinnerplate dahlias, on the other hand, can reach 4 or 5 feet in height and require sturdy staking. For more on spacing by type, see How Much Space Do Dahlias Need to Grow?.
For most medium to tall varieties, you should space the tubers about 18 to 24 inches apart. This allows for good airflow between the plants, which helps keep the foliage healthy throughout the humid summer months.
Sun and Drainage
When picking your spot, remember: right plant, right place. Dahlias need full sun—at least six to eight hours of direct sunlight every day. They also require soil that drains well. "Drainage" simply means how fast water leaves the soil. If you have a spot where puddles stand for hours after a rain, it’s not a good home for dahlias. If your soil is heavy clay, consider planting in raised beds to improve drainage.
How to Plant Your Dahlias for Success
Once the soil is warm and the frost is gone, it is finally time to plant. This is the moment your planning and early buying pay off.
Simple Planting Steps
- Dig a hole: Make it about 4 to 6 inches deep.
- Add support: For tall varieties, it is best to put your stake in the ground before you plant the tuber. This prevents you from accidentally poking a hole through the tuber later on.
- Lay the tuber flat: Place the tuber in the hole horizontally, with the eye or sprout pointing upward.
- Cover with soil: Fill the hole back up, but do not pack the soil down too hard.
- Wait to water: This is a key gardening rule for dahlias. If the soil is already slightly moist, do not water the tubers until you see the first green sprouts emerging from the ground. Overwatering at the planting stage is a common cause of rot.
What to do next:
- Check your local frost dates to determine your planting window.
- Prepare your garden beds by clearing weeds and adding a little compost.
- Set up your staking system so it's ready when the tubers go in.
Popular Varieties to Look For
When you start your search in late winter, keep an eye out for these dependable and stunning varieties. We often carry these because they perform consistently well in American gardens.
Dinnerplate Dahlias
These are the stars of the show, featuring blooms that can be 8 to 10 inches across.
- Kelvin Floodlight: A classic, giant yellow dahlia that adds a massive burst of sunshine to the garden.
- Thomas Edison: A reliable producer of deep, velvety purple blooms.
Decorative and Cactus Dahlias
These varieties offer unique textures and bold colors.
- Arabian Night: Known for its deep, wine-red color that looks almost black in certain light.
- My Love: A beautiful white cactus dahlia with spiky petals that look like a firework.
Border and Container Dahlias
If you have a smaller space or want to fill pots on a patio, look for shorter varieties. These generally don't require staking and produce a huge number of smaller flowers all season long. For more ideas, see How to Grow Border Dahlias.
Caring for Your Dahlias Through the Season
After you have bought and planted your tubers, the work becomes much lighter. Dahlias are generally low-maintenance once they get established.
Watering and Feeding
Once the plants are about a foot tall, they will appreciate a deep watering once or twice a week, depending on the rainfall. Deep watering encourages the roots to grow further down into the soil, making the plant more resilient. You can also use a balanced liquid fertilizer every few weeks to support those big blooms, but follow the label instructions carefully.
Pinching for More Blooms
To get the most flowers, we recommend "pinching" your dahlias. When the plant is about 12 inches tall, snip off the very top of the center stem. This might feel like you are hurting the plant, but it actually signals the dahlia to grow side branches. More branches mean more stems, and more stems mean more flowers for you to cut and enjoy.
Deadheading
If you aren't cutting the flowers to bring inside, make sure to "deadhead" them. This means cutting off the old, faded flowers. When you remove the spent blooms, the plant puts its energy into making new flowers instead of making seeds. This keeps the color going until the first frost of autumn.
Troubleshooting Common Timing Issues
Sometimes, despite our best efforts, things don't go exactly as planned. Here is how to handle a few common scenarios.
"I bought my tubers too late!"
If you didn't buy until June, you can still plant. Your dahlias will just bloom later in the fall. Dahlias love the cooler nights of September, so a late start can still result in a beautiful show before winter. Just make sure the tubers are still firm before you put them in the ground.
"The weather is staying cold longer than usual."
If it's June and the soil is still cold and soggy, wait. It is better to keep your tubers in storage for an extra week than to risk them rotting in the ground. Gardening requires a bit of patience, and the reward is a healthier plant.
"My tubers haven't sprouted yet."
If it has been two or three weeks and you don't see green, don't panic. Dahlias can be slow to wake up. Dig down very gently with your fingers to see if you feel a sprout. If the tuber is still firm, it is likely just taking its time. If you find the tuber has turned soft or mushy, it may have been too wet. In that case, you can replace it with a fresh one if it's still early in the season.
Dahlias: A Rewarding Long-Term Investment
One of the best things about buying dahlia tubers is that they are an investment. In most parts of the country (zones 8 and warmer), you can leave them in the ground over winter. In colder zones, you can dig them up in the fall, store them in a cool spot, and plant them again next year.
As a dahlia plant grows, it actually produces more tubers underground. This means that after a few years, you may have enough tubers to divide and share with friends or expand your garden even further. What started as a single purchase in February can become a lifelong hobby.
Conclusion
Timing is everything when it comes to a successful dahlia garden. By buying your tubers during the peak selection window of January through March, you ensure that you get the exact colors and styles you want. While you have to wait for the soil to warm up before planting, the excitement of watching those first green shoots emerge makes the wait worthwhile.
At Longfield Gardens, we are here to support you with high-quality tubers and the practical advice you need to see them thrive. Whether you are planting a single pot of border dahlias or a massive bed of dinnerplate varieties, the process is straightforward and incredibly rewarding.
- Order early to secure the best varieties.
- Wait for warm soil (60°F) before planting.
- Store tubers in a cool, dark place if they arrive early.
We invite you to explore our selection and start planning your most colorful summer yet. Gardening is a journey, and we are happy to be a part of yours.
FAQ
Is it too late to buy dahlia tubers in May?
No, it is not too late. While some of the most popular varieties may be sold out, many beautiful dahlias are still available in May. Dahlias planted in late May or even early June will still have plenty of time to grow and provide a stunning display of flowers throughout late summer and autumn.
Why do some dahlia tubers arrive earlier than others?
Shipping times are based on your USDA hardiness zone. We time deliveries so that tubers arrive about two weeks before it is safe to plant in your specific area. This prevents the tubers from being exposed to freezing temperatures during shipping and ensures you receive them when your soil is close to the ideal temperature.
Can I buy dahlia tubers in the fall?
Most retailers do not sell dahlia tubers in the fall because they are harvested in the autumn and need time to be cleaned, inspected, and stored. The primary buying season begins in late December or January when the new inventory is ready for pre-orders.
How do I know if the tuber I bought is still good?
A healthy dahlia tuber should be firm to the touch, much like a fresh potato or a carrot. It is normal for tubers to have some wrinkles or look dry on the outside, but they should not feel soft, mushy, or hollow. If the tuber is firm and has an intact "neck" where the eye is located, it is ready to grow.