How to water irises during heatwave or midday?

Watering irises during midday or during a heatwave is generally not recommended because the combination of intense heat and wet conditions can increase the risk of rotting or other issues with the rhizomes. Here are some guidelines for watering irises:

1. Watering Timing: It's best to water irises early in the morning or in the evening when the temperatures are cooler. This allows the water to soak into the soil and reach the roots before the heat of the day evaporates it. Watering during the midday heat can lead to rapid evaporation, leaving the plants thirsty and potentially stressed.

2. Watering Frequency: Irises prefer moderate watering. Aim to keep the soil evenly moist but not waterlogged. Water deeply when necessary, allowing the top inch of soil to dry between waterings. Adjust the frequency based on the weather conditions and the moisture levels of the soil. During a heatwave, you may need to water more frequently to prevent the plants from drying out.

3. Watering Method: Use a watering method that allows the water to reach the root zone without excessively wetting the foliage or the rhizomes. Drip irrigation, soaker hoses, or watering at the base of the plants are good options. Avoid overhead watering, as wet foliage can promote disease and increase the risk of rotting.

4. Soil Drainage: Irises prefer well-draining soil. If the soil doesn't drain well, it can lead to waterlogged conditions and increase the risk of rotting. Improve the soil drainage by amending heavy clay soil with organic matter, such as compost or aged manure.

5. Mulching: Applying a layer of organic mulch around the base of the plants can help retain soil moisture and regulate soil temperature. However, avoid piling the mulch directly over the rhizomes, as it can trap moisture and lead to rotting. Leave a small space around the rhizomes when applying mulch.

By following these watering guidelines, you can help prevent the risk of rhizome rot and ensure the health and vitality of your irises. It's important to monitor the moisture levels of the soil and adjust your watering practices as needed, taking into account the specific weather conditions and the needs of your plants.