Summerlong™ Lemon Agastache (Agastache mexicana ‘Balsumlem’) offers bold yellow flower spikes that emerge in late spring and keep going through summer. These bright, trumpet-shaped blooms are a pleasing sight for both gardeners and pollinators. Reaching 16 to 22 inches tall and wide, this perennial's mounded form works well in tight spaces or grouped to create a lively border. Hummingbirds and bees visit regularly. If you want a long-blooming plant for sunny conditions, this perennial is the perfect candidate.
Native to warmer regions of North America, Summerlong™ Lemon Agastache handles high temperatures and drier soil once established. It resists drought, wards off deer, and lures beneficial insects, including buzzing bees. The lemon-hued blooms and slender leaves also carry a gentle fragrance, further enhancing its ornamental appeal. Whether massed in a landscape, arranged in containers, or accenting a mixed perennial bed, Summerlong™ Lemon Agastache fits right in. With minimal demands, it thrives in various garden scenarios.
Summerlong™ Lemon Agastache Care
Use well-drained soil in a spot that receives at least six hours of sunlight daily. Water regularly for the first few weeks to help roots get established; after that, moderate or low watering is enough. A single application of balanced fertilizer in spring is usually fine—too much feeding can lead to lanky growth. Mildly acidic to neutral soil suits this plant’s needs, and adding organic matter can boost its performance. In cooler climates where temperatures dip below 15°F, consider using it as a container plant you can shelter indoors or in a protected area for the winter.
Remove spent flower spikes as they fade to encourage new rounds of blooms. Light pinching in early summer can promote a bushier habit if desired. Shearing back the plant by a few inches helps maintain tidiness and potentially spurs continued flowering. For container-grown specimens, trim lightly whenever foliage becomes overgrown or straggly. Some gardeners also perform a deeper cutback in late fall if the plant is kept outdoors year-round.
Summerlong™ Lemon Agastache Spacing
Place these perennials about 14 to 16 inches apart if creating a row or mass planting in a border. A container of roughly 12 inches in diameter is big enough to house a single plant comfortably, allowing room for root growth and easy access to water.
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Container Sizes
Please Note: The pictures below are to give a general representation of the different container sizes. The actual size/ages of plants are estimates and will vary based on type of plant, time of year, last pruning & many other factors.

Quart Pot
Also Known As:
Quart
Plant Age:
~ 6 months - 1 year
Plant Size:
~ 4"-8"
Pot Size:
~ 4.75"H x 4.5"W
Volume:
1.50 quarts

2.5 Quart
Also Known As:
2.5 Quart Pot
Plant Age:
~ 1 - 2 years old
Plant Size:
~ 8"-12"
Pot Size:
~ 6.5"H x 6.5"W
Volume:
2.20-2.30 quarts

#1 Pot
Also Known As:
#1 Container
1 Gallon
Plant Age:
~ 1 - 2 years old
Plant Size:
~ 10"-14"
Pot Size:
~ 7"H x 7.75"W
Volume:
2.26-3.73 quarts

#2 Pot
Also Known As:
#2 Container
2 Gallon
Plant Age:
~ 1.5 - 3 years old
Plant Size:
~ 12"-18"
Pot Size:
~ 9.5"H x 9.5"W
Volume:
1.19-1.76 gallons

#3 Pot
Also Known As:
#3 Container
3 Gallon
Plant Age:
~ 2 - 4 years old
Plant Size:
~ 12"-30"
Pot Size:
~9.5"H x 11"W
Volume:
2.32-2.76 gallons

#5 Pot
Also Known As:
#5 Container
5 Gallon
Plant Age:
~3-4 years old
Plant Size:
~ 20" - 60"
Pot Size:
~11" H x 10 1/2” W
Volume:
3.5 - 4 gallons

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Arrival Guarantee
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Pre-Ordered Plants
Pre-ordered plants are scheduled to ship in Spring 2025. We carefully plan our shipping dates based on your USDA Plant Hardiness Zone to ensure optimal planting conditions upon arrival. Want it sooner/later? Reach out, and we'll try our best to accommodate.
Estimated Spring Shipping Schedule
Estimated ship week for pre-ordered plants will ship based on growing zones as shown below.
Growing Zone | Estimated Ship Week |
---|---|
Zone 10 | March 24th |
Zone 9 | March 31st |
Zone 8 | April 7th |
Zone 7 | April 14th |
Zone 6b | April 21st |
Zone 6a | April 28th |
Zone 5b | May 5th |
Zone 5a | May 12th |
Zone 4 | May 19th |
Zone 3 | May 26th |
Note: These are only estimated ship dates. Plants may ship out later depending on weather & growing conditions of the plant.
Note: Only plants indicated as pre-order will ship as shown above. All other plants and hard goods will ship as normal.
Plants Shipping Now
Plants that are currently in stock typically ship within 2-7 business days after your order is placed.