Dahlias Planting Guide

June

dahlias this month

Month-by-month dahlias fundamentals. Your frost dates change the timing, so pick your county for a tailored plan.

Sun full sun

Water moderate

Days to harvest 70–120

Plant depth 5″

Spacing 18″

How to water dahlias
Consistent moisture matters more than volume for dahlias. Little and often beats occasional drenching.
Where to put dahlias
dahlias wants at least 6 hours of direct sun. Less than that and you'll get leggy plants with weak yields.
Check your local forecast before planting
Your zone determines the exact week to plant dahlias. Pick your county below and we'll line everything up against your frost dates.

Get dahlias planting dates for your county →

Dahlias (Dahlia spp.) are the undisputed stars of the late-summer and fall garden, producing an extraordinary range of flower forms — from compact pompons to dinner plate-sized blooms spanning 12 inches — in virtually every color except true blue. Blooming from midsummer until the first hard frost, a single tuber grows into a massive, flower-laden plant that can produce dozens of cut flowers per week. Modern breeding has expanded the palette and forms dramatically; the American Dahlia Society recognizes over 20 flower forms. Extremely rewarding for gardeners willing to invest in the planting, staking, and (in cold zones) annual lifting of tubers.

Dahlia spp. · Flower · Asteraceae family · 70–120 days to maturity

Bulb Blooms in Summer Pollinator-friendly Good for cutting

Why it matters: If you're just starting a flower garden in your area, Dahlias is a forgiving first pick. It tolerates imperfect soil, mild drought, and the occasional missed watering. The reward: weeks (sometimes months) of continuous color.

Get Your Personalized Dahlias Planting Dates

Enter your ZIP code to see exact planting dates, soil compatibility, and growing tips specific to your county.

Where Can You Grow Dahlias?

Zone Compatibility for Dahlias Zones 3a – 10b

1a 1b 2a 2b 3a 3b 4a 4b 5a 5b 6a 6b 7a 7b 8a 8b 9a 9b 10a 10b 11a 11b 12a 12b 13a 13b

Ideal (data available) Suitable Marginal Not recommended

Planting Dates by Zone

Zone	Start Indoors	Direct Sow	Transplant	Bloom
Zone 3a	Apr 17	May 29	May 29	Sep 4 – Oct 16
Zone 3b	Apr 12	May 24	May 24	Aug 30 – Oct 18
Zone 4a	Apr 8	May 20	May 20	Aug 19 – Oct 21
Zone 4b	Apr 3	May 15	May 15	Aug 14 – Oct 23
Zone 5a	Mar 28	May 2	May 2	Jul 25 – Oct 17
Zone 5b	Mar 21	Apr 25	Apr 25	Jul 18 – Oct 17
Zone 6a	Mar 13	Apr 17	Apr 17	Jul 3 – Oct 16
Zone 6b	Mar 6	Apr 10	Apr 10	Jun 26 – Oct 16
Zone 7a	Feb 25	Apr 1	Apr 1	Jun 10 – Oct 14
Zone 7b	Feb 25	Mar 25	Mar 25	Jun 3 – Oct 21
Zone 8a	Feb 15	Mar 8	Mar 8	May 17 – Oct 18
Zone 8b	Feb 4	Feb 25	Feb 25	May 6 – Oct 21
Zone 9a	—	Feb 10	Feb 10	Apr 21 – Oct 20
Zone 9b	—	Jan 25	Jan 25	Apr 5 – Oct 18
Zone 10a	—	Jan 1	Jan 1	Mar 12 – Oct 8
Zone 10b	—	Jan 1	Jan 1	Mar 12 – Oct 22

How to Plant Dahlias

Planting Depth

18"

Between Plants

24"

Between Rows

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

Water when the top inch of soil feels dry. Consistent moisture produces the best results.

🧪 Soil pH

6 – 7.5

Prefers neutral to slightly acidic soil — ideal for most garden beds.

🗺️ Hardiness Zones

Zone 3a – 10b

📅 Days to Maturity

70–120 days

Medium-season crop. Start early for best results in shorter seasons.

👪 Plant Family

Asteraceae

Rotate with other families yearly to prevent soil-borne diseases. Don't plant in the same spot where Asteraceae family crops grew last year.

Succession Planting Dahlias

Dahlias matures in just 70–120 days, making it ideal for succession planting. In a typical 180-day growing season, you can get up to 2 successive plantings by sowing every 8 weeks.

Your actual succession count depends on your local frost dates. Enter your ZIP code to get personalized succession planting dates for your area.

Companion Planting for Dahlias

✅ Good Companions

Zinnias Marigolds Salvia Cosmos Gladiolus

Check more combinations with our Companion Planting Checker →

Growing Tips for Dahlias

Plant tubers after all danger of frost has passed and soil temperature reaches 60°F — typically 1–2 weeks after last frost in most zones. Lay tubers horizontally 4–6 inches deep with the eye (growth point) facing up. Do not water until sprouts emerge; wet soil rots dormant tubers. Stake tall varieties (over 3 feet) at planting time to avoid root disturbance later. Pinch growing tips at 12–16 inches to encourage branching and more blooms. Deadhead regularly to extend the blooming season. In zones 8b and warmer, tubers can overwinter in the ground with a layer of mulch. In zones 3–8a, lift tubers after the first killing frost, cure for a week, and store in slightly damp vermiculite or peat at 40–50°F until spring. Divide tubers every year or two; each division must have an eye (bud) to grow.

Saving Dahlias Seeds

Recommended for Your Garden

🌱

Seed Starting Trays $8-20

Start seeds indoors with reusable cell trays and humidity domes.

🧪

Soil Test Kit $12-25

Test your soil pH, nitrogen, phosphorus, and potassium levels before planting.

🏷️

Garden Plant Markers $6-12

Keep your garden organized with durable, weather-resistant plant labels.

Reader favourite

Seed Saving & Storage Guide

$27 $157 value

Most saved seeds go bad before next season. This shows exactly when to pick, how to dry, and where to store seeds from 200 plants so yours don't.

200 plants, step-by-step: life cycle, pollination type, isolation
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Dahlias by State

Frequently Asked Questions

How long does it take to grow Dahlias?

Dahlias (Dahlia spp.) takes 70 to 120 days from planting to harvest. Exact timing depends on your variety, growing conditions, and USDA zone.

What zones can Dahlias grow in?

Dahlias can be grown in USDA zones 3a through 10b. Use the planting calendar above to find the exact dates for your zone.

How much sun does Dahlias need?

Growing Dahlias requires Full Sun (6-8+ hours), Moderate — regular watering, and soil pH of 6 to 7.5.