Herbs are excellent choices for container gardening. This mixed herb container was made by the Pine Belt Master Gardeners. (Photo by MSU Extension/Gary Bachman)
Summer is a great time for herbs as they love sunshine and warmth. But too much heat can stress your plants, especially when growing in containers. Unlike garden beds, herb growing containers heat up quickly, dry out faster, and give roots less room to spread. If you’re not careful, your herbs can go from thriving to wilting in a day or two.Here’s how to keep your container herb garden healthy and productive, even during the hottest weeks of summer.
Choose the right container material
The type of container you use affects how much heat and moisture your herbs are exposed to. Some materials, like metal or dark plastic, absorb and retain more heat. That can make root zones too warm, drying the soil and stressing the plant.
Lighter-colored containers made from ceramic, fabric, or wood are usually better for hot weather. If you prefer metal or composite containers for durability, consider placing them in partial shade during the afternoon or lining them with insulation to reduce heat buildup.
Drainage is also critical. Make sure your herb growing container has holes at the bottom to prevent water from pooling and causing root rot.
Water deeply and consistently
Container herbs dry out faster in the summer, so you’ll need to water more often. But the key isn’t just how often but also how you water them.
Water deeply so the moisture reaches the full root system. Quick surface watering often isn’t enough. Stick your finger into the soil; if it’s dry two inches down, it’s time to water. Early morning is the best time to water because it gives your plants moisture for the day and reduces water loss through evaporation.
On extremely hot days, you may need to water twice once in the morning and once in the evening. Try not to water during the day’s peak heat, when much of the water evaporates before it reaches the roots.
Use mulch to retain moisture
Adding a thin layer of mulch to your herb growing container helps keep the soil cool and moist. Organic mulch, like shredded straw, compost, or chopped leaves, works well. It acts like a shade cloth for your soil, reducing evaporation and protecting roots from direct sun exposure.
Keep mulch about one inch deep and leave a little space around the base of the herb to avoid trapping too much moisture directly against the stems.
Give your herbs some shade in extreme heat
Most herbs love the sun, but even sun-loving plants like basil or thyme can wilt if temperatures soar past 90°F (32°C) day after day. If your herbs are getting too much direct sun, consider moving them to a spot with partial afternoon shade.
If your containers are too large to move easily, you can use shade cloth, a patio umbrella, or even a light bedsheet during the hottest part of the day. A break from the direct sun reduces plant stress and keeps the soil from overheating.
Feed your herbs sparingly
In the summer, your herbs grow fast and use up nutrients in the soil. But be careful not to over-fertilize. Too much nitrogen can make your plants leafy but weak, and they may bolt or burn in high heat.
Use a diluted, balanced organic fertilizer once every 3–4 weeks. Liquid seaweed or compost tea are good, gentle options. Feeding lightly helps maintain steady growth without overwhelming your herbs.
Trim regularly to reduce stress
Harvesting your herbs regularly helps them stay compact and healthy. Removing older leaves improves airflow, reduces water loss through transpiration, and encourages fresh growth.
Focus on trimming herbs like basil, mint, and oregano every week. Always use clean scissors or pruners, and cut just above a set of leaves to encourage branching. Avoid heavy pruning during extreme heat, but don’t let herbs grow wild either; they’ll use more water and become less productive.
Conclusion
Summer heat doesn’t have to ruin your herb garden. With the right care, your herbs can grow strong through the hottest days. It starts with choosing the right herb growing container, watering deeply and consistently, and protecting your plants from extreme sun and heat.
Herbs are resilient, but they do need your attention in the summer. Small changes like adding mulch, moving a pot, or trimming back growth can significantly affect how your plants handle the heat.
