Gregg’s mist is a captivating, native perennial that butterflies can’t resist! Here’s everything you need to know about taking care of this butterfly magnet, including the amazing reason butterflies flock to its blooms.
If you’re thinking of starting or expanding a butterfly garden, Gregg’s mist (Conoclinium greggii) is a “must have” addition.
This semi-evergreen perennial is native to riparian areas of the Chihuahuan Desert. In its natural habitat, it grows along stream beds.
It is a lovely plant that would not look out of place in a woodland. It has vivid green lacy leaves and clusters of fuzzy ageratum-like periwinkle flowers from spring through fall.
But the main reason to plant Gregg’s mist is for the butterflies.
Numerous moths and some butterflies use it as a larval host. When in bloom, butterflies, especially queen butterflies, find Gregg’s mist simply irresistible. Flowers also attract migrating monarchs.
(To learn why queens can’t resist this plant, jump to the end of this article.)
Like milkweeds, Gregg’s mist reliably attracts butterflies, but without the downsides. Milkweeds are toxic to both humans and pets. Also, they attract insects not everyone welcomes, such as aphids and, in the case of desert milkweed, tarantula hawk wasps. Gregg’s mist, on the other hand, has no pests — just butterflies!
Why I Like This Plant
- Bright green foliage
- Delicate fuzz lavender-blue flowers
- Long bloom season — spring through fall
- Attracts swarms of butterflies
- Low-maintenance, no litter
Things to Watch Out For
- Some people find this plant irritating to touch
- Needs more water than many native plants
- Toxic to livestock
Fun Fact!
A group of butterflies can be called a swarm,
flutter, flight, rabble, wing, or kaleidoscope.
Optimal Growing Conditions
If you’re thinking of adding Gregg’s mist to your garden, you need to find a suitable place that will keep your plant healthy and looking good… while minimizing maintenance for you.
Here are the key factors to keep in mind.
Temperature
Gregg’s mist should be grown in USDA Hardiness Zones 7 – 10. It’s tolerant of desert heat and cold. Where winters are warm, it can stay green all year, but it dies back when temperatures reach the 20s. It’s root-hardy down to 0℉ and bounces back in the spring.
Sun Exposure
Gregg’s mist grows in full sun or partial shade, but will not withstand reflected heat. When planted in full sun, it flowers more but needs more water. When planted in dappled shade, which is ideal in the desert, it doesn’t produce as many flowers, but the foliage looks better, and it gets by on less water.
Size and Growth Rate
Gregg’s mist grows moderately fast and grows faster with more water. It spreads by underground stems called rhizomes and forms clusters that typically reach a size of 2′ tall by 2-3′ wide.
When growing conditions are ideal, it can grow “enthusiastically” but not aggressively. It is not hard to keep in bounds.
I’ve seen them planted where they spread into sidewalk cracks in the summer, but die back every winter. A friend of mine had hers pulled out by a “helper” who thought it was a weed. It grew back the next spring, looking good as new.
Soil
Gregg’s mist grows in rocky, clay, or sandy soil, provided it’s well-draining. It prefers soil that is somewhat alkaline.
Other Location Considerations
Of course, Gregg’s mist is a “must have” for any butterfly garden. But you can also grow this versatile plant as a ground cover, border plant, or in containers where you can watch the butterfly activity up close.
Gregg’s Mist:
The Essentials
| Common Names | Gregg’s mist, Gregg’s mistflower |
| Scientific Name | Conoclinium greggii |
| Origin | Chihuahuan Desert |
| Plant Type | Semi-evergreen perennial |
| USDA Zones | Zones 7 – 10 |
| Cold Hardy | To 0℉ |
| Flower Color | Lavender-blue |
| Flower Season | Spring, summer, fall |
| Mature Size | 1-2′ high x 2-3’ wide |
| Growth Rate | Moderate |
| Sun Tolerance | Full, part sun |
| Water Needs | Moderate |
| Pests & Diseases | None |
| Cautions | Contact dermatitis Toxic to livestock |
| Wildlife | Attracts butterflies, moths Moth & butterfly larval host |
How to Plant
The rule of thumb when planting any perennial in the desert is to dig a hole twice as wide as the root ball but no deeper. Plant slightly higher than ground level, allowing room for some settling and mulch.
Amending the soil is not recommended. Counterintuitively, backfilling with the same native soil you just dug up helps your plant develop a stronger root system.
When to Plant
The best time to plant Gregg’s mist is in the fall. This gives it three seasons to grow roots and get established before the following summer.
The second best time is in spring, the earlier the better. This still gives your plant time to get established before the intense heat of June arrives.
If you want to move or divide an existing plant, do it in the spring, after the last chance of frost.
How to Care for Gregg’s Mist
Whether you’ve recently planted a Gregg’s mist or have an existing one in your yard, here’s how to take care of it to keep it healthy and looking its best.
How to Water
While Gregg’s mist is a southwest native, this classification can be misleading since it’s native to riparian regions. In its natural habitat, it grows along stream beds. Consequently, plants in the garden require a moderate (rather than low) amount of water.
Also, plants need more water when grown in full sun than they do when grown in part shade.
The usual recommendation is to water every week in full sun and every 10 days to two weeks in part shade. But I’ve found mine to be pretty thirsty and water them twice a week in the summer. These plants will tell you when they’re dry by wilting.
How to Prune
Gregg’s mist usually dies back in the winter, so prune it back in early spring to make way for new growth. Even if your plant doesn’t die back, it’s recommended that you prune it in the spring anyway to encourage new growth and bushiness.
I also cut my plants back by about 1/3 in August, since they get a little raggedy by then.
Should You Fertilize?
Gregg’s mist doesn’t need fertilizer, but extra nutrients help these plants bloom prolifically. The Arizona-Sonora Desert Museum’s plant care guide recommends fertilizing Gregg’s mist in the spring and again in mid-summer.
Why Queens Flock to Gregg’s Mist
Gregg’s mist produces a natural alkaloid, intermedine, that is poisonous to livestock but is essential to queen butterfly reproduction.
When male queens visit this plant, they ingest intermedine which is converted into a pheromone that attracts the females. Intermedine also makes the females’ eggs unpalatable to predators.
How Can You Tell Queens from Monarchs?
If your Gregg’s mist has butterflies, you may be unsure whether they’re monarchs (Danaus plexippus) or queens (Danaus gilippus). Most likely, they’ll be queens, but as you can see below, they look a lot alike, and the differences can be subtle.
Plant Lover Facts
Gregg’s mists goes by a long list of alternative tongue-twisting names and variations of spellings:
Gregg’s mistflower, palmleaf mistflower, palmleaf thoroughwort, purple palmleaf eupatorium, purple palmleaf mistflower, Texas ageratum, and thoroughwort. (Many palmleaf variations are also spelled palm-leaf.)
Earlier scientific names that you may still come across are Cococlinium dissectum and Eupatorium greggii.
Gregg’s mist is native to parts of New Mexico, Texas, and northern Mexico. In Arizona, its natural habitat is restricted to Cochise County.
Did you enjoy this article?
Sign up for our weekly newsletter
where you’ll find more great info on creating &
maintaining a beautiful, carefree desert landscape.
Author Bio
Deane Alban is the creator of Southwest Gardener. She is a science writer with a bachelor’s degree in botany from the University of South Florida. Gardening is her lifelong passion. She’s been gardening in Tucson for 15 years.
