The Iowa Gardener: Gardening in a drought

It’s been a dry summer, presenting major challenges for gardeners who want to keep their lawns healthy and flowers and vegetables growing strong.

As of July 13, Linn County was officially designated by the U.S. Drought Monitor as being partly “abnormally dry” and partly in “moderate drought.” Counties to the southeast have fared better and rainfall is within usual levels. But counties to the northwest are in either moderate or severe drought.

The drought, especially in the West, is deeply concerning and record-breaking. But it’s also useful to note that droughts play an important role in nature’s cycle of self-correction. Drought brings with it a whole set of challenges, but it also counteracts problems that occur during wet years. During dry spells, fungal and some other diseases that thrive in moist conditions are diminished. So are populations of problem insects that rely on wet conditions.

But that’s not going to keep those new trees you planted alive. Here are some ways to cope with dry spells and outright drought.

Pick your battles. You probably don’t need to keep every single thing in your yard well watered. For example, in my garden, I spent $450 on several arborvitae trees this spring for a new hedge. Already, two have portions that are turning brown. I’m focusing my watering time, energy and money on keeping those well watered because they are a big, permanent investment. My cucumbers? Meh. Not so much. I can just buy some instead, if I have to.

Consider letting your lawn go dormant. In Iowa, as long as a drought isn’t too severe and too extended, it’s fine to stop watering your lawn and let it go brown. It looks like heck, of course, but it will come back nice and green next spring. Do not, however, start watering again once your lawn goes dormant. Bringing it in and out of dormancy stresses it. Wait to do any further watering next year.

Water smart. Water plants deeply and occasionally rather than often and shallow. On average, plants we choose for our Iowa gardens need one inch of water a week. That can be hard to achieve in dry conditions, but do your best. Deep watering encourages a stronger and deeper root system, which better sustains plants during hot, dry spells. Watering deeply keeps more moisture in the soil. This means there is less evaporation.

Keep weeding. Weeds compete with desirable plants for sun, nutrients and, you guessed it, water. Get rid of weeds so they don’t rob your flowers and vegetables and other plantings of critical moisture.

Measure. If you don’t have a rain gauge, get one so you know exactly how much rain your landscape is getting. When you put out your sprinkler, put a shallow dish or bowl out to so you can see how many inches of water you are applying.

Invest in soaker hoses or a drip irrigation system. If you can find any to buy — there’s been a run on these from stores and suppliers recently — these efficient watering systems slowly put water right on the roots so there’s minimal runoff and evaporation. There’s also no waste, like when a sprinkler ends up watering your sidewalk along with your lawn.

Mulch. Mulching keeps soil cooler, suppresses weeds and keeps the ground moister longer. Apply one to three inches of mulch, such as wood chips, grass clippings, or straw, to your garden and flower beds to shield the ground from direct sun. Around permanent plantings, like shrubs, you can also use landscape fabric for even more control. In vegetable gardens, put down newspapers first and then top with grass or straw for even more mulch power.

Dead head diligently. Plants that are going to seed expend large amounts of energy and need more water. Trim off spent flower heads immediately so the plant can focus its limited energy on staying alive.

Avoid herbicides. Applying some herbicides when it is too hot can turn liquid formulations to gas and can cause harmful drift. Also, weeds don’t do a good job of taking up herbicides during dry conditions, so they’re less effective anyway.

Avoid pesticides applied directly to the leaves of plants. In hot, dry conditions, some types can damage the leaves.

Avoid fertilizer. Fertilizer promotes fast growth, which needs ample water to support that growth. Also, without frequent rains to flush out the soil, fertilizer salts can build up in the soil and potentially burn plants.

Veronica Lorson Fowler is co-publisher of The Iowa Gardener website at theiowagardener.com.