Heliotrope
How to Grow Heliotrope in Arizona: A Zone 9b Growing Guide
If you're looking for a fragrant, cottage-style flower for your Arizona garden, heliotrope is an excellent choice. Its deep marine purple flowers, dark green foliage, and sweet vanilla- or cherry-pie-like fragrance work beautifully in containers, raised planters, and boarder gardens.
Although heliotrope is a tender perennial in warm climates, we prefer to grow it as a cool-season annual in Zone 9b, enjoying it primarily in fall and spring. Arizona's intense summer heat can be difficult for heliotrope, so afternoon shade and seasonal planting are important.
Heliotrope at a Glance
Botanical Name: Heliotropium arborescens
Common Names: Heliotrope, Cherry Pie Flower
Plant Type: Tender perennial, commonly grown as an annual
Flower Color: Purple to deep violet
Mature Height: Approximately 12–24 inches
Mature Width: Approximately 12"
Spacing: About 9"
Light: Full sun to partial shade
Water: Moderate; prefers consistently moist but well-draining soil
Bloom Season in Arizona: Primarily fall through spring
Best Arizona Use: Containers, borders, cottage gardens, mixed annual beds, and fragrant gardens
Most annual heliotropes grow about 1–2 feet tall and wide, though size varies by cultivar.
When to Plant Heliotrope in Zone 9b Arizona
Fall Planting
Plant transplants after the intense summer heat breaks, generally starting in October or November.
Because it is frost tender, protect plants with frost cloth when temperatures approach freezing, or move containers to a sheltered location.
Spring Planting
The second planting window is approximately February through March, depending on local temperatures and frost risk. This gives plants several months to flower before summer heat arrives. We typically spring plant flowers in the container garden so we do not have to protect seedlings from frost.
How to Start Heliotrope from Seed
Heliotrope is easy to grow but not particularly fast. Start seeds approximately 8-10 weeks before transplanting outdoors.
For Fall Planting, start seeds indoors around Late July to Mid August.
For Spring Planting, start seeds around Late November through December for late-winter or early-spring transplanting.
Sowing Heliotrope Seeds
Use a fine-textured seed-starting mix and surface sow seeds. Sprinkle seeds on top of soil and do not cover with soil. Sprinkle a very light layer of vermiculite on top of cell to help prevent algae growth. Again, do NOT burry seeds as they need light to germinate.
Place humidity dome onto of tray and put it underneath a growlight until you see germination.
Maintain a soil temperature of approximately 70–75°F. Germination may take 2–4 weeks or longer.
We sowed seeds on July 25th - and these are what the seedlings looked like on August 11th 17 days later.
Seedlings 12 days later on August 23rd
After seedlings emerge, provide bright light to prevent stretching. Once they develop several true leaves, transplant them into larger cells or small pots. We feel them every time we water with 1/4 strength liquid fertilizer. We typically use Jacks classic 20-20-20.
Pinching Heliotrope Seedlings
Pinch young plants after they develop several sets of leaves and begin growing vigorously. Removing the growing tip encourages branching, producing fuller plants and more flowering stems.
Where to Plant Heliotrope in Arizona
Heliotrope can tolerate full sun during Arizona's coolest months. As temperatures are warm, morning sun with protection from intense afternoon sun can extend the flowering season in early fall or late spring.
Plant heliotrope in rich, well-draining soil that does not completely dry out. Incorporate compost or other organic matter into native soil. For containers, use a quality potting mix with good drainage.
What Flowers Pair Well With Heliotrope?
Heliotrope's deep purple flowers and dark foliage pair especially well with white, blush pink, lavender, apricot, and soft yellow flowers.
Favorite companions include:
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Spring Flower Pairings
- Dahlias – Add height and large, dramatic blooms behind heliotrope.
- Lavatera – Soft, romantic flowers create a relaxed cottage-garden look.
- Hollyhocks – Tall flower spikes make a beautiful backdrop for lower-growing heliotrope.
- Celosia – Adds contrasting texture and bold color as temperatures warm.
- Petunias – Perfect for filling the front of beds or spilling from containers.
Fall Flower Pairings
- Celosia – Adds bold color and interesting texture alongside heliotrope.
- Marigolds – Golden and orange blooms create a striking contrast with purple heliotrope.
- Ornamental Millet – Provides dramatic height and dark foliage.
- Zinnias – Peach, coral, pink, orange, and burgundy varieties create an abundant fall display.
- Cockscomb – Adds large, velvety blooms and unique texture.
A Beautiful Addition to the Arizona Cottage Garden
Heliotrope's deep purple flowers, dark foliage, compact habit, and sweet fragrance make it a valuable addition to Arizona cottage gardens.
Start seeds early, plant during the cooler fall or spring windows, keep the soil consistently moist, and provide afternoon protection as temperatures rise.
For Zone 9b gardeners, heliotrope is best viewed not as a summer annual, but as a beautiful fall-through-spring flower suited to Arizona's unique growing seasons.
Find our favorite Heliotrope seeds available in our shop.
