As happens this time of year, the weather in the Desert Garden is suddenly really hot. The thermometer aside, there is always that one day as we inch through the calendar when we realize that Summer is here to stay.
One of the questions I'm asked most often this time of year is, "How often should I water?" The only accurate answer, as frustratingly vague as it may be, is, "Deeply, but infrequently." There are general guidelines and recommendations, but to water effectively and efficiently you need to spend a little time looking at your own garden and landscape to see how the plants are responding; the combination of plants, sun, shade, soils, heat, etc., is in every garden unique, and your watering will reflect that.
For our quince here, watering to a depth of three feet, as wide as the drip line, every two weeks, has seemed to work well. Last week though, I noticed some slight wilting on the leaves. That wilting — and any wilting for that matter — means that the water demand from the plant is higher than the rate at which the plant can draw water to meet that demand.
For a healthy plant, such as our quince, that often means a lack of soil moisture, but that isn't always the case with every plant. Wilting, remember, only means that the water demand is higher than the plant can meet. There are a number of possible reasons why the plant can't meet the demand: too little water in the soil, too much water in the soil, rotted roots, mechanically damaged roots, a disease of the xylem (water-carrying tissue), or simply a very hot day with a high evapo-transpiration rate. Before watering a wilting plant, first consider checking the soil for moisture, especially if you've watered very recently. We kill more plants in the Desert Garden through over-watering than by under-watering.
As an example, if you're growing squash or another large-leafed cucurbit in your garden this Summer, you will notice that the leaves wilt mid-day. That's just what they do. If you water every time you see that wilt, you'll rot out your roots in no time flat. Instead, get your finger down under the mulch and into the soil; if the soil is damp, hold off on the watering and you'll see the plant bounce back in the evening.
As it turns out, when I poked my finger down in the soil under the quince, it was dry. That means with the hot weather arriving, every two weeks is insufficient. I now have it scheduled for about every 10 days, and I'll keep an eye on it to make sure that works.