Dahlias can easily be planted in pots as well. If you dont have much space and would like to enjoy dahlias on your terrace or balkony, this is possible! Dahlias can thrive in large containers; tall varieties also need a stake for extra support. With the right growing conditions and a little care, you’ll enjoy your dahlias in pots all summer
Dahlias are one of the most popular tuberous flowers grown by home gardeners. With their vibrant colors and unique forms, it’s no wonder they are a favorite for beds, borders, and containers. When planning your dahlia garden, an important question is how many tubers to plant per pot. Follow some key guidelines to get the right balance and enjoy a beautiful dahlia display.
Factors That Determine Dahlia Tubers Per Pot
Several elements come into play when deciding the ideal number of dahlia tubers for each pot. Consider the following factors:
Size of the Pot
Bigger pots can accommodate more tubers. Aim for at least a 12-inch diameter container. Shallow pots won’t allow the tubers to develop properly.
Dahlia Variety
Compact dwarf dahlias can be spaced closer than tall border or giant dahlias that become large plants. Check tag or catalog info.
Growing Conditions
More tubers planted close together require extra water and nutrients to support all the growth
Time to Maturity
Young, newly planted tubers tolerate crowding better than mature, fully grown plants.
Recommended Amounts of Dahlia Tubers Per Pot
As a general guideline when planning dahlias in pots, follow these suggestions:
- 10-12 inch pots – 1 tuber
- 14-16 inch pots – 2-3 tubers
- 18+ inch pots – 3-5 tubers
However, also keep these tips in mind:
- Allow at least 1 tuber per 10-12 inch pot for giant varieties over 4 feet tall.
- When mixing different dahlias in a container, choose mostly dwarf types and space further apart.
- If planting mature tubers close together, transplant them to the garden within 4-6 weeks.
- Always leave at least 8 inches between tubers at the container edges for air circulation.
Planting a Single Tuber Per Pot
One dahlia tuber per pot is the easiest approach and prevents overcrowding issues Benefits include
- Ample space for foliage and blooms to develop.
- Good air flow to the roots and plant.
- Less competition for water and nutrients.
- Maximum sunlight exposure for vibrant blossoms.
- Avoidance of later thinning or transplanting.
- Each variety can stand out nicely on its own.
For success with single tubers per pot:
- Use at least a 12-14 inch container.
- Bury 1 inch deep, eye/sprout side up.
- Check moisture 1-2 inches down and water when dry.
- Fertilize every 2-3 weeks during growth with balanced liquid fertilizer.
Getting More Dahlias Per Pot
If you want to fill your pots with as many dahlias as possible, follow these tips:
- Allow 8+ inch spacing between tubers at pot edges.
- Water more frequently for thirsty crowded roots.
- Apply extra fertilizer to feed multiple plants
- Watch for signs of overcrowding and stunted growth.
- Be ready to thin or transplant tubers later if needed.
Dahlia Tuber Combination Examples Per Pot
Here are some suggested pairings for planting more than one dahlia tuber per container:
10-12 inch pot:
- 1 Dinnerplate Dahlia + 1 Dwarf Bedder Dahlia
- 1 Medium Cactus Dahlia + 1 Short Pompom Dahlia
14-16 inch pot:
- 1 Tall Cut Flower Dahlia + 2 Dwarf Bedders
- 3 Small Decorative Dahlias in Complementary Colors
18+ inch pot:
- 1 Giant Dahlia + 2 Medium Varieties
- 5 Compact Bedding Dahlias for Continuous Color
Get creative mixing heights, forms, and colors that complement each other in the pots. Just avoid crowding the tubers too closely.
Key Tips for Growing Dahlias in Containers
Beyond tuber spacing, follow these tips to keep potted dahlias thriving beautifully:
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Use at least a 12 inch wide/deep container or bigger. Plastic holds water better than terra cotta.
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Fill with well-draining, nutrient-rich potting mix. Mix in compost or manure.
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Ensure pots have drainage holes to prevent soggy soils. Add pebbles for improved drainage.
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Stake tall, top-heavy dahlias at planting to support stems and big blooms.
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Place in full sun, minimum 6 hours of direct light per day. Protect from wind.
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Pinch off first buds to encourage bushy, compact growth habit.
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Deadhead spent blooms for extended flowering into fall. Stop deadheading by early September so tubers can form.
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Bring containerized dahlias indoors before fall frost to overwinter the tubers.
By following these guidelines on the ideal number of dahlia tubers per pot, you can enjoy a vibrant container dahlia display. Experiment with different variety combinations, pot sizes, and tuber spacing to find what works best for your garden.
What kind of pot is suitable for planting dahlias in pots?
Take a big pot of at least 30 cm (12″) and preferably of sturdy ceramic or terracotta. Make sure the pots are well-drained, if not make extra holes. Preferably add a small layer of gravel, hydro grains or shards on the bottom.
Which dahlia varieties are most suitable for pots?
Dwarf and low-growing dahlia varieties are best for container growing. You’ll need a larger pot if you choose a tall species. A single tuber needs about 30 to 60 cm (1 or 2 feet) of space, so you’ll only need 1 dahlia tuber per container. If you plant more dahlia tubers in one pot, they might get too little sunlight.
How to Plant Dahlia Tubers in Pots for Earlier Blooms
FAQ
Can I plant 2 dahlia tubers in one pot?
Add 1 tuber per pot or if you have big pots (>45 cm diameter) you can plant 3 tubers per pot.
How many dahlias in a 12 inch pot?
A single tuber needs about 30 to 60 cm (1 or 2 feet) of space, so you’ll only need 1 dahlia tuber per container. If you plant more dahlia tubers in one pot, they might get too little sunlight.
Do dahlias like to be crowded?
Each dahlia plant will require at least 12” of space, so choose a container a minimum of 16” wide and equally deep, and be sure not to over-crowd your dahlias. While tubers may look small when planted in pots, remember that they grow into large plants, and they need their space.
How close together can you plant dahlia tubers?
Most Dahlias are spaced with approximately one tuber per square foot. The largest varieties of Dinner Plate Dahlias will do best with wider spacing, about 12-18 inches apart, to allow for foliage and flowers to grow. Compact varieties can be planted with multiple tubers per square foot.
Can you put a dahlia tuber in a potting mix?
PHOTO NO. 1: The potting mix just covered the dahlia tuber when it was placed on the bottom 1/3 mixture of soil and copolymer slurry. The eye of the root was left exposed. The plant has grown beyond the top of the pot and has been staked, so it is ready to be completely filled in with potting soil. The lower leaves will be covered with soil.
How big should a dahlia tuber be?
preview our dahlia tuber shop opening March 1, 2025! Plant dahlias in containers that are at least 12” deep and 16” wide. The bigger the pot, the better. Each dahlia tuber needs a minimum of 12”x12”x12” of space to grow well. Don’t plant too many dahlia tubers in one pot! Plant once all danger of freezing has left the forecast.
How many dahlia tubers in a pot?
The average 12-inch pot should only have one dahlia tuber in it. That’s the minimum required space for a single dahlia plant to grow successfully without getting overcrowded, competing over resources, or having its sunlight exposure limited. When planting a dahlia tuber in a pot, make sure the tuber is between 4 and 6 inches deep into the soil.
How big should a dahlia pot be?
The bigger the pot, the better. Each dahlia tuber needs a minimum of 12”x12”x12” of space to grow well. Don’t plant too many dahlia tubers in one pot! Plant once all danger of freezing has left the forecast. Pots heat up quicker than the ground, so if properly cared for, you might get earlier blooms!
How do you grow a dahlia plant in a pot?
To encourage healthy growth both above and under the soil, plant the dahlia tuber in a large container with at least 2 feet of space between the tubers. It takes more than just enough space and a healthy tuber to grow a successful dahlia plant in a pot. Read more to find out the necessary prerequisites for a thriving potted dahlia.
What pots do you grow dahlias in?
ERIN: The pots I’m most successful growing dahlias in are wooden barrels, I think because of the size and drainage. I put bigger tubers, or more tubers, in the really big barrels that are 24”x24” wide. I have a concrete front porch, which holds heat and keeps the pots going longer into the season as opposed to placing the pots on the ground.