All plants mentioned below are proven to do well in our hot, dry summers and are suitable for our Zone 4.
Like many places, we are experiencing longer, hotter summers. According to Extreme Weather Watch, our area experienced 64 days of 90 °F or hotter days, and a whopping 75 days in 2020.
The trend continues to creep upwards, so it's important to plant for what we now know is our new gardening 'normal' where we live.
These plants like the heat are are adaptable to a range of growing conditions, making them great choices for our high altitude, typically dry and hot summer gardens.
What makes a plant heat tolerant?
A heat-tolerant plant has adaptations that help it survive and thrive in high temperatures and intense sunlight. These traits include deep or extensive root systems that reach water stored deeper in the soil, waxy or hairy leaves that reduce moisture loss through evaporation, and the ability to close stomata (tiny pores) to limit water loss during the hottest parts of the day. They have a unique resistance to prolonged periods of drought.
Some heat-tolerant plants also have light-colored or reflective foliage that deflects sunlight, efficient water storage tissues, and built-in mechanisms to protect vital cells from heat stress, all of which allow them to maintain growth and productivity even during prolonged heat waves.
All plants shown in the photo above are in the order listed below:
Prevent heat-tolerant plants from wilting in extreme heat
Heat-tolerant plants can wilt in extreme heat if they’re under too much stress — but you can help them by proactively managing water, shade, and soil health.
Water deeply and less frequently: Give plants a good soak early in the morning, so moisture reaches deeper roots where it won’t evaporate as fast. Avoid shallow, daily watering.
Mulch generously: Add 2–4 inches of mulch (like straw, bark, or compost) around the base of plants. This insulates roots, keeps soil cool, and reduces evaporation.
Provide temporary shade: For delicate or young plants, use shade cloth, row covers, or even an old sheet during the hottest part of the day.
Space plants well: Good air circulation reduces heat stress and helps foliage stay cooler.
Avoid stress during peak heat: Don’t prune, transplant, or fertilize heavily when temperatures soar — this can increase wilting.
Keep soil healthy: Well-amended, organic-rich soil holds water better and supports deep rooting.
The trend continues to creep upwards, so it's important to plant for what we now know is our new gardening 'normal' where we live.
These plants like the heat are are adaptable to a range of growing conditions, making them great choices for our high altitude, typically dry and hot summer gardens.
What makes a plant heat tolerant?
A heat-tolerant plant has adaptations that help it survive and thrive in high temperatures and intense sunlight. These traits include deep or extensive root systems that reach water stored deeper in the soil, waxy or hairy leaves that reduce moisture loss through evaporation, and the ability to close stomata (tiny pores) to limit water loss during the hottest parts of the day. They have a unique resistance to prolonged periods of drought.
Some heat-tolerant plants also have light-colored or reflective foliage that deflects sunlight, efficient water storage tissues, and built-in mechanisms to protect vital cells from heat stress, all of which allow them to maintain growth and productivity even during prolonged heat waves.
All plants shown in the photo above are in the order listed below:
- Abelia
- Agastache
- Red Hot Pokers
- Black-Eyed Susan
- Gallardia/Blanket Flower
- Coneflower/Echinacea
- Coreposis
- Lavender
- Marigold
- Catmint
- Salvia
- Yarrow
- Zinnia (not shown in photos above)
Prevent heat-tolerant plants from wilting in extreme heat
Heat-tolerant plants can wilt in extreme heat if they’re under too much stress — but you can help them by proactively managing water, shade, and soil health.
Water deeply and less frequently: Give plants a good soak early in the morning, so moisture reaches deeper roots where it won’t evaporate as fast. Avoid shallow, daily watering.
Mulch generously: Add 2–4 inches of mulch (like straw, bark, or compost) around the base of plants. This insulates roots, keeps soil cool, and reduces evaporation.
Provide temporary shade: For delicate or young plants, use shade cloth, row covers, or even an old sheet during the hottest part of the day.
Space plants well: Good air circulation reduces heat stress and helps foliage stay cooler.
Avoid stress during peak heat: Don’t prune, transplant, or fertilize heavily when temperatures soar — this can increase wilting.
Keep soil healthy: Well-amended, organic-rich soil holds water better and supports deep rooting.