Relief came with the rain.

The unyielding, sweltering blast furnace of 100-plus degrees for days on end has desiccated the garden and taken prisoner all my green treasures. After day after day of blistering sun, no trace of humidity remained. The wind rattled dead leaves down from the sycamore until they piled six inches deep and crunched crisply under my feet. All the trees have been wilting, withering in the heat. The hostas have knelt down, submitting to the heat in limp amber circles as dormancy was thrust upon them by the intense temperatures and drought. This is not October, just the worst July in Missouri history.

And the rains we prayed for finally came over the weekend. As the dark clouds swirl around us and the torrents of rain come down, pounding the few remaining leaves into limp rags, my husband and I sit in the sheltered nook of our porch watching the storm sweep over the valley. In only a few hours, the plants still living will pull this precious water into their vessels and restore firmness to their torpid leaves.

Flagging is too gentle a word for what this garden is experiencing. In horticulture, we call the extreme PWP – permanent wilting point. It is the degree of water loss from which a leaf, or whole plant, cannot recover. It is a certain crisping beyond limp leather and on to the potato chip stage, which cannot be restored to health with water. Our summer crops here in west St. Louis County have curled up and fried with the dry winds. I’ve heard of farmers preparing their insurance papers for crop loss. Still, this much-needed rain may salvage something.

In my garden, the box elder tree was the first to go, a casualty of the drought, turning a sickly yellow green, then brown, then dead. Following close behind were the red bud trees, with too many dry pods rattling in the breeze; their plan for survival is to set a million seeds. I had thought to write this column then, as the heat was blasting and driving us into the air-conditioned havens of our offices and homes, but I was, instead, dragging water hoses and sprinklers from one beloved tree to the next every few hours, even late into the moonlit nights.

I have been through this before. A severe drought in Charlotte, back in the 1980s, found me caring for the ancient trees of a historic churchyard in the center of the city. With nearly 200 years of history and one of the few large urban green spaces, these trees were important to both the congregation and the community. The mandatory water restrictions were so severe then that sprinkling was allowed only between midnight and 4 a.m.: The trees were near to death from drought.

With more than two acres to cover and no irrigation system for delivery, how do you put enough water out for an entire city block of massive old, towering oak trees wilting with water stress? You call in the troops -– in this case the city fire department. They were our heroes, armed with reams of hoses and pumping from four fire hydrants, starting at the stroke of midnight, they blasted enough water out in a few hours to save the trees. We performed these moonlight ablutions once a week for most of the summer.

My regard for the strength needed for a firefighter to do their job increased exponentially as I tried to wrestle the water-wild fire hose. Think of holding a 200-pound anaconda against its will. No small feat. And we were able to save all the trees but one.

With this kind of season, forget the grass. It can be reseeded in the fall without too great an expense. But our trees represent years, decades, even centuries of growth. They give us beauty, shade, flowers and clean the air.  Their anchor in the landscape is more important than that of any other single type of plant. They give our gardens grace and our streetscapes scale.

It takes only one killer season to steal them away from us. Driving through the city, there are too many trees dead or dying. I can spot the signs of stress a mile away, but this is my passion and profession. For the average homeowner, it may not be clear that a tree is in trouble until it is too late.

The standard rule of thumb is one inch of water across the whole root zone each week. If Mother Nature does not supply this, supplement it with soaker hoses, irrigation or sprinklers. With these extreme temperatures, our trees are weakened and more water is needed to replace that lost by the leaves in transpiration. We have a break in the heat for the moment, but this worse-than-ever summer has many more brutal weeks in store. Stay ahead of the curve. Water now.

The dark clouds have delivered their gifts of water, thunder and lightning. The late evening sunset sneaks out from behind. Rosy puffs of distant sky reflect the last light. The tree frogs have begun their evening song and the wilted trees are lifting up their leaves in applause. We are all thankful for the rain.