Bring it on! The monsoon is here!

Even though the bright sun and dry heat say otherwise, monsoon season begins today.

This storm season will make a dramatic entrance with blinding dust storms, torrential rains that flood the desert and surrounding urban areas, and raging rivers that cause flash floods. Lightning and thunder from the storms cause people and animals to run for shelter and the winds will bend even the strongest trees.

Our rising temperatures in the past few decades also escalate monsoon storms. The warm air causes low pressure and draws ocean water from the Gulf and California. Our winds that normally blow from west to east will come from the southeast then almost swirl around us and head east. (See the maps below from the University of Arizona, Article az1417) Monsoon season will hang over the Southwest from June 15 through Sept. 30, and peak from mid-July through mid-August.

The season is a double-edged sword because we need the rain, which makes up one-third to one-half of our water, but it may bring with it a wave of destruction. If we prepare and understand the season, we can use it for our benefit, but if we don’t prepare our landscape for the storms, its gift of rain may be the death of many of our trees and plants.

It’s still not too late to give a bit of gentle pruning to your trees to protect them and your property. Your focus should only be to open up the airflow a bit so the wind can pass through. Also remove the dead wood before the wind does it for you. Too much pruning right now can hurt most trees so do what you need to do but no more.

Stake young, newly planted trees if (and only if) the southeastern monsoon wind will likely damage it. You should stake the tree in the opposite direction of the monsoon wind, so place one stake northeast of the tree and the other southwest. If the tree looks strong after the monsoon season, remove the stakes. Use correct staking techniques at all times. The “Smiling Gardener” created a good video that describes three staking methods.

Flowers are blown around in the strong winds and their petals drop. Deadhead the spent flowers to keep the plant healthy. Cut the stem below the flower just above the first healthy set of leaves (for roses, the set should have five leaves). Make your cut at about a 45-degree angle so that the rain flows off it. This will prevent disease and bacteria in the new wound.

After a dust storm, spray your shrubs, ground cover and vegetable gardens to remove the dust. Just like a good shower for you, the spray will re-open the pours of your plant leaves.

The rain is what makes this season worth the drama. It replenishes groundwater and wildlife. Our plants (and weeds) experience tremendous growth. Wildlife, insects, and pollinators are abundant. And let’s not forget all of the fun it provides for our kids as they slosh through the water and the mud! To children, monsoon rain in the desert is equal to the first snow in the Northeast.

Oddly enough, we have to prepare our often water-starved plants for the abundance about to rain down upon them. With the heavy rains, tomatoes will fill with water, swell and crack. Mildew may also appear on your vegetable plants.

Use this time as a blessing and not a curse. Watch the sky and cut back on water according to rain predictions. If we get a hard rain, you can hold your watering schedule back for several days. Your soil surface may appear dry after a day or two, but test it with your finger to see if it is still damp at root level.

To prevent flooding around your plants, add organic matter to the soil to aerate it (compost, worm castings, etc.) and mulch with straw. I like straw rather than dry leaves for vegetable gardens because straw doesn’t compress as much as dry leaves in the rain. Organic matter and mulching will also help your trees and shrubs, although you can use wood chips in place of straw for them if you prefer that look.

I know that some of you may think I am a bit crazy for saying this, but lightning is good for your vegetable garden and landscape plants. We have a lot of nitrogen in the air in a calm environment. In fact, our air is 78 percent nitrogen and 20 percent oxygen. However, nitrogen in the air can’t bond to the oxygen molecules. Nitrogen is what makes our plants grow so fast and strong and since they can’t get it through the air normally, we feed them through the soil by applying compost and fertilizers. During a monsoon storm, lightning increases the heat and electrically charges the air. This causes the nitrogen and oxygen to bond and form nitrogen oxides, which then replenish your plants through nitrates in the rain. Without the electricity, nitrogen won’t transmit through rain to your plants.

So when your dog is smothering you or your cat is clawing you in the middle of the night in fear, hug and stroke them, then whisper, “Don’t worry, sweetie. The tomatoes are happy tonight.”

Keep yourself and your plants safe this season so you can enjoy the rain. Just don’t dance in it if lightning is present. You don’t need the extra nitrogen!


I am a certified agriscape designer and Maricopa County Master Gardener. I have been gardening since I was six years old and worked in my grandfather's garden. I believe that the only way to be a responsible gardener is to garden organically. It improves our soil, is safer for us to eat, sustainable and it protects our pollinators and soil from chemical poisoning.