Aster Growing Guide
Aster is a great next step in your growing journey. Follow this guide from planting to harvest and you'll do great.
At a Glance
Difficulty
Moderate
Category
Flower
Sun Exposure
Full Sun, Partial Sun
Frost Tolerance
Frost Hardy
Growing Zones
Zones 3, 4, 5, 6, 7, 8
Plant Family
Asteraceae
Growing Season
Warm Season
Plant Lifecycle
Annual
Also grows well as
When To Start
First Chance to Plant
7 Days After Last Frost
Last Chance to Plant
30 Days Before First Frost
When should you plant Aster?
Your planting dates depend on where you live. Sign up to unlock dates personalized to your location.
Your Aster Planting Window
Start planting
May 15, 2026
Last chance
Sep 10, 2026
The Journey Ahead
Aster's Lifecycle
Seedling
Mature Plant
Seed Production
Step 1
Prepare Your Space
0.5 cm
Seeding Depth
30 cm
Plant Spacing
45 cm
Row Spacing
4
Plants / Sq Ft
Vertical Growing
Yes – Trellis.
Method: Trellis.
Succession Planting
Yes.
Step 2
Planting & Sprouting
Expect sprouts in 7–14 days
Growing Tips
- 1Plant asters in a spot where they can get full sun for at least 6 hours a day.
- 2Water them regularly, keeping the soil consistently moist but not waterlogged.
- 3Use well-draining soil enriched with compost, and space the plants about 1 to 3 feet apart to ensure good air circulation, which helps prevent powdery mildew.
Seedling Phase
Step 3
Growth & Maturity
~90
Days to Maturity
60 cm
Mature Height
60 cm
Mature Width
Pests to Watch For
Diseases to Watch For
Mature Plant
Step 4
Harvesting
Harvest Window
30 days
When to Pick
Cut flowers at peak bloom
How to Harvest
- 1Harvest Aster flowers when they are fully open but before they start to wilt.
- 2Use sharp scissors or pruning shears to cut the stems at an angle, about 6 inches from the base, to encourage regrowth.
- 3Avoid pulling the stems to prevent damaging the plant.
Step 5
Saving Seeds
How to Save Seeds
Saving seeds from your Aster plant is a simple and rewarding process that any new grower can master! Once the flowers have faded and the seed heads turn brown and dry, gently snip them off and place them in a paper bag to finish drying for a week or two. Then, simply rub the seed heads between your fingers to release the small seeds. Store your collected seeds in a labeled envelope or small jar, and keep them in a cool, dry place until you’re ready to plant next season. With just a little effort, you’ll have your own homegrown Aster seeds ready to grow and share—saving seeds is a wonderful way to continue your gardening journey!
Seed Production
