Watering in Hot Weather and During Vacations

Photo: Torsten Dattlaff

Summer is upon us, and with it come the occasional bouts of extreme heat. Water is essential for plant survival, but the question of how much is not always easy to answer. Many factors determine how much water your garden needs, including soil type, temperature, sun exposure, wind, and other weather conditions. One thing is certain, however: plants need more water during periods of extreme heat.

Container plants are especially vulnerable to drying out. During the summer months, particularly when temperatures rise above 80°F, most potted plants should be watered thoroughly until water runs out of the drainage holes at the bottom of the pot. (This does not apply to plants that prefer drier conditions, such as cacti, agaves, euphorbias, and other succulents.)

Vacations can present additional watering challenges. If you plan to be away for more than a week, you will likely need to ask someone to water your containers. A trip of a week or less is usually more manageable. Here are a few tips to help your potted plants survive while you’re away.

First, move containers to a shaded location, such as beneath trees or on a covered patio. Water them thoroughly just before you leave. Avoid applying fertilizer, as it can encourage new growth and place additional stress on plants during hot weather. Finally, mulch the soil surface with a thick layer of bark chips or compost to help reduce moisture loss and keep the roots cooler.

Moving pots to a shady location can greatly increase their success during a prolonged absence. (Photo: Zoryana Lavruk)

Plants growing in the ground are generally less susceptible to heat and drought stress, especially if they are watered deeply before you leave on vacation or a day or two before a predicted hot spell. As with container plants, a generous layer of mulch helps retain soil moisture, reduces evaporation, and keeps roots cooler.

Newly planted trees and shrubs will require the most attention. One effective solution is a tree watering bag. These bags fit around the base of a tree trunk and are filled with water that slowly trickles out through small openings at the bottom, providing a deep, gradual soaking. They can also be used for large shrubs by positioning the bag close to the base of the plant.

Another option is to attach a timer to a sprinkler or irrigation system. Timers can be programmed to run automatically on the days and times you choose. For overhead sprinklers, morning watering is ideal because it allows foliage to dry during the day, reducing the risk of fungal diseases. Timers are also available for drip irrigation systems and for watering container plants, making them a convenient solution when you’re away from home.

Tree watering bags provide slow, deep watering for trees and shrubs. (Photo: Treegator)