Agastache
( AG - uh - stash )
At-A-Glance Information
This herbaceous perennial genus of flower also known as Hummingbird Mint or Giant Hyssop is a dependable garden choice, and blooms during the summertime through to fall. They are best known for their fragrant foliage and flowers come in shades of pink, apricot, coral, yellow, white, purple, blue, red and orange. These plants make great drought-tolerant additions to borders, and will rebloom in the same year if deadheaded. The flowers will attract hummingbirds and other pollinators to your yard. The foliage can be used to make teas, jams, potpourris, for flavor as culinary dishes, and the flowers are great in fresh arrangements, making these flowers some of the most useful in the garden.
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Agastache Species and Varietals
The genus Agastache includes 22 species of flowering plants, and is part of the family Lamiaceae. The name is derived from the Greek words for 'very much' and 'ear of grain', and was first established by botanist Jan Frederik Gronovius. The best growing zones for Agastache depend on the species; see the descriptions below for more information. To find your zone, click here: Zone Map. There are two sections within the genus Agastache: Typical Giant Hyssops (Agastache) and Hummingbird Mints (Brittonastrum).
Typical Giant Hyssop (Agastache) Species
These species are native to western to central North America, across the Bering Strait to eastern Asia. The upper lip of the corolla on these plants is small, causing the stamens to protrude more dramatically.
These species are native to western to central North America, across the Bering Strait to eastern Asia. The upper lip of the corolla on these plants is small, causing the stamens to protrude more dramatically.
Agastache cusickii (Cusick's Giant Hyssop) This species is native to the northwestern United States from Oregon and central Nevada to Idaho and Montana. It naturally grows in alpine and sagebrush ecosystems. These plants form a taproot and have white flowers with purple tips. At maturity, Cusick's Giant Hyssop reaches 4-8 inches tall. |
Agastache foeniculum (Anise Hyssop) This species grows best in zones A3 and 1-24 and is native to north to central North America. This is an erect and narrow plant, reaching 3-4 feet tall and 2 feet wide. Lilac blue flowers appear in clusters, and leaves are licorice-scented. Great for borders and herb gardens, and can tolerate winter cold and wet better than other species. |
Agastache occidentalis (Western Giant Hyssop, Giant Horsemint) This species is native to seasonably wet areas in the Cascade Mountain Ranges in Oregon and Washington. Spring to early summertime flowers are light purple to purple, and the plant reaches 3 feet tall at maturity. This species was first described by Charles Vancouver Piper, and was given its current name by Amos Arthur Heller. |
Agastache parviflora (Small-Leaf Giant Hyssop) This species is endemic to northern California, where it is at home in wild woodland areas. This species is somewhat uncommonly seen, and is, by some authorities, placed in the same species as Agastache urticifolia. Flowers have tubular pink corollas and pink-tipped green sepals. |
Agastache rugosa (Korean Hummingbird Mint, Wrinkled Giant Hyssop, Indian Mint, Chinese Patchouli) Grows best in zones 4-24 to 5 feet tall and 2 feet wide. This plant is native to Korea and purple-tinted green foliage is licorice-scented. Varieties include 'Golden Jubilee' (2-3 feet tall and 2 feet wide with yellow-green new growth), and 'Honey Bee Blue'. |
Agastache urticifolia (Nettleleaf Giant Hyssop, Horse Mint) This plant is native to British Columbia down through California and Colorado, and can grow in many types of wild habitats. This species was and still is used medicinally by many Native American populations. Flowers are pink-purple and bloom on spikes that rise above the foliage. |
Hummingbird Mints (Brittonastrum)
This section of the Agastache genus has species native to the southwestern United States and northern Mexico. Flowers on these species have a larger, more developed upper lip, and stamen are generally hidden from view.
This section of the Agastache genus has species native to the southwestern United States and northern Mexico. Flowers on these species have a larger, more developed upper lip, and stamen are generally hidden from view.
Agastache aurantiaca (Orange Hummingbird Mint) This species of Agastache is native to Northern Mexico, and can be grown as an annual in cold or particularly wet regions. Grows best in zones 3-24. Gets to 2.5 feet tall and 2 feet wide with pink flowers that age to orange. Variety 'Coronado' (pictured) has yellow blooms with an orange tint. |
Agastache cana (Texas Hummingbird Mint, Mosquito Plant, Double Bubble Mint) This plant grows best in zones 2-24, and is native to Texas and New Mexico. Grows to 2-3 feet tall and 1.5 feet wide. Heavy reddish pink fragrant blooms smell of bubblegum. Varieties include 'Heather Queen' and compact-grower 'Purple Pygmy' (16 inches tall). |
Agastache Hybrids
These plants grow best in zones 4-24, and are very popular choices for bringing in pollinators to gardens.
These plants grow best in zones 4-24, and are very popular choices for bringing in pollinators to gardens.
Agastache 'Apricot Sunrise'
Grows best in zones 2b-24. Gets to 3 feet tall and wide. Flowers are deep orange and fade to apricot when they bloom. |
Agastache 'Blue Fortune'
This 3 feet tall, 1.5 feet wide plant has powder-blue spikes of flowers. |
Agastache 'Cotton Candy'
Gets to 2 feet tall and wide, with spikes of pink flowers. |
Agastache 'Firebird'
2-3 feet tall and 2 feet wide. Flowers are copper-orange, coral-pink and red. |
Agastache 'Raspberry Summer'
This plant grows to 2.5 feet tall and 2 feet wide, with large spikes of dark pink flowers. |
Agastache 'Summer Breeze'
Grows best in zones 6-24, to 3 feet tall and 2 feet wide. Flowers are large and lavender pink, leaves are grey-green. |
Agastache mexicana (Giant Mexican Lemon Hyssop)
Grows best in zones 3-24 and is a native to Mexico. Gets 2-3 feet tall and 1 foot wide. Pink flowers bloom profusely from spring to late fall. Leaves are lemon-scented, and can be used in teas and as seasoning. The Acapulco series of varietals have flowers that are salmon-pink, rose-pink and orange. Variety 'Fortune' has red flowers and 'Sangria' has reddish-purple flowers. |
Agastache pallidiflora (New Mexico Giant Hyssop, Bill Williams Mountain Giant Hyssop) This species reaches four feet tall, and has white to purple flowers that bloom in July through October. Leaves are semi-evergreen. This species favors the environment of moist canyons. Subspecies include Agastache pallidflora pallidiflora and Agastache pallidiflora neomexicana. A popularly grown varietal is 'Rose Mint'. |
Caring for Agastache
To avoid shocking your plant, introduce it to your garden in the cooler months of spring or fall. They enjoy sun, so pick a corresponding spot in your yard. Agastache plants prefer well-draining soil with a pH between 6.0 and 8.0, amended with compost or other organic matter. To plant, dig a hole slightly larger than your plant's pot, break up roots (especially if the plant has become root-bound in its nursery container), and place it in the planting hole so the top of the root ball is even with or just a little bit higher than the surrounding soil. Fill in the hole with more amended soil and water thoroughly. Until it is established, it will enjoy receiving regular water. If you are planting your Agastache in a container, use the same soil described and ensure that the pot is well-draining.
Agastache are relatively drought-tolerant after they are established. They do not need to be fertilized, but do like to have a layer of compost applied in springtime. As far as pruning goes, deadhead flowers to promote rebloom, and plants can be pinched to encourage a bushier habit. They will naturally die back to the ground in late fall, and at this time dormant stems should be cut back by about half. To encourage healthy root systems and prevent overcrowding, plants should be divided once every three to five years. For instructions on how to divide your Agastache plant, see the directions below in the Propagation section.
Agastache are relatively drought-tolerant after they are established. They do not need to be fertilized, but do like to have a layer of compost applied in springtime. As far as pruning goes, deadhead flowers to promote rebloom, and plants can be pinched to encourage a bushier habit. They will naturally die back to the ground in late fall, and at this time dormant stems should be cut back by about half. To encourage healthy root systems and prevent overcrowding, plants should be divided once every three to five years. For instructions on how to divide your Agastache plant, see the directions below in the Propagation section.
Propagation
Agastache can be propagated in three ways: by division, by seed, and by cutting. If you would like a true clone of the plant you are propagating, choose either the division or cutting methods of propagation.
Propagating Agastache by Division
Your Agastache will need to be divided every three to five years, and this is a great time to propagate the plant, as well. Division allows for more room for existing roots, and will improve the health of your plants. The best time to use this method of propagation is when it starts to develop new growth in the springtime. Divide your plants in the morning, when the roots won't be exposed to too much heat while they're out of the soil. You will need a clean shovel, a pruning knife, soil amended with compost, and pot(s) (if you will not be immediately planting your propagated plant in the ground). To propagate your Agastache by division, follow these directions:
Propagating Agastache by Cutting
The best time to take cuttings from an existing plant is in summer right before it begins to bloom and new growth is abundant. Agastache can be propagated from either soft or hard wood cuttings, and you'll end up with a propagated Agastache that has the same characteristics as its parent. You'll need clean, sharpened garden shears, rooting hormone, potting mix amended with compost, a pot (or pots, depending on how many cuttings you'll be taking), and a pencil. Once you've gathered your materials, follow these instructions:
Propagating Agastache by Seed
Before trying this method, keep in mind that propagation by seed does not ensure that you will end up with the exact same plant as you harvested the seed from. If you are looking for an exact clone of the parent plant, propagate your Agastache by division or by cutting. To complete this propagation method, you will need to allow flowers to stay on the plant long enough to come to seed, so do not completely deadhead all of your flowers when they fade. Seeds will be mature and ready to harvest in late fall, when the flowers have dried and are brown in color (see the image below). Cut the flower heads off of your plant at this time, and take the seeds out of their pods. To grow Agastache from seed, follow these directions:
Propagating Agastache by Division
Your Agastache will need to be divided every three to five years, and this is a great time to propagate the plant, as well. Division allows for more room for existing roots, and will improve the health of your plants. The best time to use this method of propagation is when it starts to develop new growth in the springtime. Divide your plants in the morning, when the roots won't be exposed to too much heat while they're out of the soil. You will need a clean shovel, a pruning knife, soil amended with compost, and pot(s) (if you will not be immediately planting your propagated plant in the ground). To propagate your Agastache by division, follow these directions:
- Identify the area of plants you're going to divide. Start by loosening the soil around the plant with your shovel, working your way inward to avoid causing damage to the roots. Once you've gotten your clump out of the ground, lay it out on its side.
- Divide the clump into segments, either with your shovel or with a pruning saw, as many as you'd like as long as there are enough roots per segment to ensure the division will survive.
- If you will be planting your Agastache in the ground, this is when you'll prepare your new hole. Dig a hole (large enough to accommodate the root ball of the clump you are planting) in the ground with your shovel in a sunny location with compost-amended soil that is well-draining. Backfill and water generously.
- If you are transporting your division elsewhere, or hanging on to it until you're ready to plant it, you'll need your pot filled with amended soil. Dig a hole large enough to accommodate the root ball of your division, and place your new plant in the soil. Water generously, ensuring that adequate drainage is occurring. Place the pot in a sunny location until you are ready to plant it in the ground.
Propagating Agastache by Cutting
The best time to take cuttings from an existing plant is in summer right before it begins to bloom and new growth is abundant. Agastache can be propagated from either soft or hard wood cuttings, and you'll end up with a propagated Agastache that has the same characteristics as its parent. You'll need clean, sharpened garden shears, rooting hormone, potting mix amended with compost, a pot (or pots, depending on how many cuttings you'll be taking), and a pencil. Once you've gathered your materials, follow these instructions:
- Choose a plant to propagate. It should be a healthy plant, with new growth and should get some water the night before you take your cutting. Pick a healthy stem tip that has both mature leaves and new leaf buds and make a 4- to 6-inch cutting. Cut quickly and evenly to take the healthiest cutting possible.
- Add potting medium to your pot, and give it some water, ensuring that it has good drainage. Make a hole with your pencil in the medium, about two inches down. Dip your cutting in rooting hormone and place your cutting in the hole.
Fill in soil around it and pat down just enough so the cutting stands up by itself. Give it some water. - Keep the soil around your plant somewhat moist as it grows, and ensure that it is in a place that gets bright indirect light and stays at a temperature of between 68 to 75 degrees Fahrenheit. Rooting should occur in around ten days. Your new Agastache will be ready to be planted in the garden the next spring, once the danger of frost has passed.
Propagating Agastache by Seed
Before trying this method, keep in mind that propagation by seed does not ensure that you will end up with the exact same plant as you harvested the seed from. If you are looking for an exact clone of the parent plant, propagate your Agastache by division or by cutting. To complete this propagation method, you will need to allow flowers to stay on the plant long enough to come to seed, so do not completely deadhead all of your flowers when they fade. Seeds will be mature and ready to harvest in late fall, when the flowers have dried and are brown in color (see the image below). Cut the flower heads off of your plant at this time, and take the seeds out of their pods. To grow Agastache from seed, follow these directions:
- Gather your materials. You will need a pot or seed tray and soil amended with compost and a spray bottle filled with water.
- For best results, sow seeds indoors or in a greenhouse about six weeks before your last frost will occur. Your seedlings will be ready for planting in the garden in springtime. If you are growing just a few seeds, you can use a pot, though if you are growing more than just a few, use a growing tray. Prepare your pot or growing tray by filling it with potting medium.
- Place your seeds on top of the potting mix, spaced about 4- 6 inches apart. Sprinkle potting medium over the top until the seeds are covered. As the seeds are starting out, it is best to use a spray bottle to add moisture to avoid uncovering their light soil topping. Keep the soil moist as the seeds develop and maintain a soil temperature of 55 degrees Fahrenheit.
- Continue to monitor for moisture, adequate soil covering and soil temperature until the seeds start to sprout, which can take about 30-50 days. Once the chance of frost has passed by, seedlings can be transplanted to a sunny area of the garden and planted a foot apart. Keep the soil moist as the plant develops and be patient waiting for blooms as they may take a while to develop.
Problems and Pests
Keeping your Agastache healthy requires monitoring for various issues, including:
- Spider Mites
- Thrip
- Aphids
- Whitefly
- Slugs
- Powdery Mildew
- Rust
- Botrytis
- Leaf Spot and Leaf Blight
- Root Rot
Gallery
Videos
All about Agastache!
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A fun Plant Chat about Agastache.
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How to Grow and Care for Agastache plants.
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A video about Blue Fortune Agastache.
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Learn about Agastache plants.
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How to care for Hyssop in the garden.
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Resources
The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Pages 137-138, Agastache
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