Heatwave Hyssop

Agastache ‘Heatwave’ is an upright, warm-season perennial with medium-green foliage and tall spikes of magenta-pink flowers. Its bloom and vertical shape suit sunny mixed borders, containers, and cutting gardens; in colder climates it can be grown as an annual. ## Garden Use Use it as a vivid mid-border accent or repeat it in groups for a long summer display. The flowers are useful for cutting and attract butterflies and hummingbirds. The cultivar is identified as ‘Heatwave’ in [US plant patent PP19662](https://patents.justia.com/patent/PP19662), which describes its large bright-magenta flowers and broad upright growth. ## Siting and Size Give it full sun and well-drained soil. Avoid sites that remain wet through winter; excess winter moisture can be more limiting than summer dryness. [Perennials.com’s exact-cultivar profile](https://www.perennials.com/plants/agastache-heatwave.html) gives mature dimensions of 29–35 inches tall by 18–23 inches wide and lists USDA zones 5–10, so allow room for its upright clump; colder areas may treat it as an annual. ## Seasonal Interest Flower spikes appear from mid to late summer. The flowers add strong color and can be cut for arrangements. These timings can shift with local climate and growing conditions. ## Maintenance Plant in a freely draining bed and water during establishment. Afterward, water as needed during prolonged dry weather. Remove spent flower spikes for a tidier appearance or to encourage additional flowering.