If you live where summers are hot and dry, irrigation or the lack thereof can mean life or death to prized plants. These tips will help your garden survive the dog days.
— Check your automatic irrigation system. Trust me, it needs it. Watch for leafy growth blocking sprayers, clogged riser heads, and plugged drip lines.
— Pay particular attention to soil moisture during heat waves and desiccating winds.
— If the root zone goes dry, supplement auto irrigation with hose watering.
— If the ground is concrete-hard, leave a hose dripping overnight to create an underground cone of moist soil.
— Use a hose-end sprayer—ideally one with multiple settings—to direct water where you want it.
— Take the opportunity when hose-watering to blast pests, fallen leaves and dirt out of leaf axils.
— Water early in the morning or late in the day. Note to desert gardeners: Watering in midday heat can literally cook roots. (Eek!)
— Trees and shrubs want water where their canopies would naturally direct rainfall: around the perimeter of the plant.
— A hose lying in summer sun may contain scalding water. You already know this, but your house-sitter may not, so be sure to mention it.
— If you have a hose-full of hot water, aim a fine spray skyward. Droplets will cool by the time they hit leaves.
— To help hold moisture in the soil, cover bare ground with mulch, gravel or fallen leaves.
Specifically for succulents ~ all of the above, plus…
Aeoniums, dudleyas and other succulents that have closed their rosettes should be watered minimally or not at all, lest dormant roots rot. The plants will revive when the rains return. (They may not make it until then, though, if in full sun. If so, shade them.)
See my latest video, Succulents, Sun and Summer ~
What about potted succulents? From my website’s FAQ’s: Aim to keep soil about as moist as a wrung-out sponge. About once a week should do it. Water thoroughly to soak the roots and flush salts. Let common sense prevail: Water more during hot, dry spells and less or not at all during periods of high humidity, cool temperatures and rain.
Find more info in my books: Page 56 of Succulents Simplified, pp. 219-222 of Succulent Container Gardens, and pp. 134-135 of Designing with Succulents (second edition).