Dahlia Growing Basics
-
When to plant: When soil is consistently around 60°F and danger of frost has passed.
-
Sun: Full sun; some afternoon shade can help in very hot climates.
-
Soil: Fertile and well-draining.
-
Planting depth: About 4–6 inches.
-
Position: Lay the tuber horizontally with the eye facing upward.
-
Water: Avoid heavy watering before growth emerges; then water deeply as plants establish.
-
Support: Stake tall varieties early.
-
Pinching: Pinch young plants to encourage branching and more usable flowering stems.
Tools and Materials You'll Need
Before you begin, gather these essentials:
- Dahlia tubers (healthy, firm, with visible eyes)
- Hand trowel or shovel
- Garden stakes and twine
- Soil thermometer
-
Soil amendments (based on a soil test)
- Sluggo Plus or similar pest control
- Plant labels
-
Peat moss, coco coir, or potting mix (optional for pre-sprouting)
Pre-Planting & Warming Up Your Tubers (Optional)
Pre-sprouting is not necessary, but it can give dahlias a head start—especially in areas with a shorter growing season. About four weeks before you expect outdoor planting conditions to be ready, you can bring your tubers into a warm environment to encourage the eyes to begin growing.
Place the tubers in a container or bag with a loose growing medium such as peat moss, coco coir, or potting mix, keeping the medium only lightly moist. Check the tubers periodically for developing eyes or sprouts and for any signs of rot.
If you prefer to skip this step, that's perfectly fine. Dahlia tubers can be planted directly outdoors once the danger of frost has passed and the soil has warmed to around 60°F.
Step 1: When and How to Plant Dahlias
Timing is everything. Wait until your soil temperature reaches at least 60°F before planting. Cold soil is one of the most common causes of dahlia failure.
You can use a soil thermometer or check online soil temperature data for your ZIP code. Choose a sunny location with well-draining soil. Dahlias love full sun, though in very hot regions they'll appreciate some light afternoon shade.
Planting Steps:
-
Dig a hole 4–6 inches deep.
-
Lay the tuber horizontally with the eye or sprout facing up.
-
Insert your stake before covering with soil to avoid damaging the tuber later.
-
Backfill gently and label the variety.
-
Water sparingly until you see growth above ground—especially in wet climates. Overwatering can cause rot before the roots establish.
Tip: In dry climates, lightly moisten the soil occasionally so it doesn't go bone dry, but never let the tuber sit in soggy conditions.
To protect your emerging shoots, sprinkle Sluggo Plus or another organic pest deterrent over the soil surface.
Step 2: Caring for Growing Dahlias
Once your plants are about 12 inches tall, you can pinch the central growing tip to encourage branching and a bushier plant. Pinching may delay the first blooms slightly, but it can encourage more branching and is especially useful when growing dahlias for cutting.
Ongoing Care
-
Water deeply 1–2 times per week depending on your soil type and climate. Sandy soil requires more frequent watering than clay.
-
Tie plants to stakes every 12–18 inches of growth to support heavy blooms.
-
Deadhead spent flowers regularly to encourage new buds and extend the flowering season.
-
Fertilize lightly every 3–4 weeks with a balanced, low-nitrogen fertilizer once growth is established.
If strong winds or storms break a stem, don't panic—cut it back and your plant will send up new shoots in no time.
Step 3: End of Season & Storing Dahlia Tubers
When frost arrives, your dahlia season comes to an end. Wait one to two weeks after a hard frost, when the foliage has blackened, before digging. This allows the tubers to "harden off" for better winter storage.
-
Cut down the plant to a few inches above the soil.
-
Gently dig up the clump, being careful not to damage the tubers.
-
Rinse off the soil and divide the clump if desired.
-
Label each variety clearly.
-
Store in a cool, dark location that remains safely above freezing. Aim for roughly 40–50°F, and check tubers periodically through the winter for excessive drying or rot.
We store our tubers in plastic totes with wood shavings or peat moss, but there are many successful storage methods depending on your climate and storage conditions.
Bonus Tips from Ribier Gardens
-
Rotate your planting areas yearly to reduce disease pressure.
-
Mulch lightly to regulate soil moisture and temperature.
-
Label every plant—you'll thank yourself later when your field is a sea of blooms.
-
Start with healthy tubers from a trusted source. Look for firm tubers with an intact crown and a visible eye or viable growth point.
Final Thoughts
Growing dahlias is one of gardening's greatest joys. With a little patience and care, your garden will soon be bursting with color, texture, and life.
At Ribier Gardens, we take pride in sharing not only the finest dahlia tubers but also the knowledge that helps you grow them beautifully.
Ready to start your own dahlia patch?
Shop Dahlia Tubers
How to Grow Dahlias: Planting, Care & Tuber Storage
Dahlia Growing Basics
Tools and Materials You'll Need
Before you begin, gather these essentials:
Pre-Planting & Warming Up Your Tubers (Optional)
Pre-sprouting is not necessary, but it can give dahlias a head start—especially in areas with a shorter growing season. About four weeks before you expect outdoor planting conditions to be ready, you can bring your tubers into a warm environment to encourage the eyes to begin growing.
Place the tubers in a container or bag with a loose growing medium such as peat moss, coco coir, or potting mix, keeping the medium only lightly moist. Check the tubers periodically for developing eyes or sprouts and for any signs of rot.
If you prefer to skip this step, that's perfectly fine. Dahlia tubers can be planted directly outdoors once the danger of frost has passed and the soil has warmed to around 60°F.
Step 1: When and How to Plant Dahlias
Timing is everything. Wait until your soil temperature reaches at least 60°F before planting. Cold soil is one of the most common causes of dahlia failure.
You can use a soil thermometer or check online soil temperature data for your ZIP code. Choose a sunny location with well-draining soil. Dahlias love full sun, though in very hot regions they'll appreciate some light afternoon shade.
Planting Steps:
Tip: In dry climates, lightly moisten the soil occasionally so it doesn't go bone dry, but never let the tuber sit in soggy conditions.
To protect your emerging shoots, sprinkle Sluggo Plus or another organic pest deterrent over the soil surface.
Step 2: Caring for Growing Dahlias
Once your plants are about 12 inches tall, you can pinch the central growing tip to encourage branching and a bushier plant. Pinching may delay the first blooms slightly, but it can encourage more branching and is especially useful when growing dahlias for cutting.
Ongoing Care
If strong winds or storms break a stem, don't panic—cut it back and your plant will send up new shoots in no time.
Step 3: End of Season & Storing Dahlia Tubers
When frost arrives, your dahlia season comes to an end. Wait one to two weeks after a hard frost, when the foliage has blackened, before digging. This allows the tubers to "harden off" for better winter storage.
We store our tubers in plastic totes with wood shavings or peat moss, but there are many successful storage methods depending on your climate and storage conditions.
Bonus Tips from Ribier Gardens
Final Thoughts
Growing dahlias is one of gardening's greatest joys. With a little patience and care, your garden will soon be bursting with color, texture, and life.
At Ribier Gardens, we take pride in sharing not only the finest dahlia tubers but also the knowledge that helps you grow them beautifully.
Ready to start your own dahlia patch?
Shop Dahlia Tubers