Monday’s Strictly Opinion: Angie’s Theory

Bear with me, as I am about to post for the umpteenth time about proper watering.  I have just cause-most problematic issues I am dealing with now regarding the landscape have to do with water.  A scheme for watering the plants has been the hottest topic of our season, given the high heat, and the utter lack of rain.  I mean to discuss the water that your plants, garden, and landscape require.  Thoughtful and dispassionately informed watering makes a difficult season more manageable.  I hope by association to address the problems that arise from too much water.  My clients who have not watered, or who have overwatered-we have a discussion pending,   

Our August nights have been on the cool side- downright chilly.  I ordinarily dial back the water when the nights cool off.  This makes sense.  Cool temperatures means water evaporates from the soil at a slower rate.  Hot days do not tell the entire story.  The night time story is a story line worth following.   My advice?  Ignore the day temperatures.  Follow the night temperatures.

Overly wet soil under any circumstances, hot or cold,  can result in root rot.  Rotted feeder roots means that no matter how much water is available to absorb, the mechanism for that absorption has been destroyed.  A plant with root rot cannot absorb any water from the soil.  Your worried watering may be killing your plants. Why am I blathering on about the importance of proper watering?  A misguided hose, watering can, or sprinkler system kills more plants than any other factor.  Too much water kills more plants than drought, insects, or disease.  Too much water can sicken and endanger an entire landscape. 

Those gardeners that never water anything are not really gardeners.  Those gardeners that water over and over again given a tough summer season are fearful gardeners.  I understand that fear-I reacted to the steamy heat and dry with my hose, open full blast.  But I see now that my off the top of my head reaction was harmful.  Thoughtful watering makes for a great landscape and garden.  As Buck says, be cool, and assess the situation.  Being cool, and properly assessing the situation-a good thing.   This is my theory.  Cool off.  Observe before you make a move.  Water only when there is a call for water. Do not water solely thinking you will help plants suffering in the heat.  Plants have an extraordinary will to live.  A drink now and then will help them to survive.  An ocean of water -they may drown.   

Consider these simple examples.  Japanese iris love wet ground-during their growing season, that is.  Flooded fall and winter ground will kill them.  Lavender can endure heavy clay-meaning astonishly water retentive soil-over the summer, but winter wet will kill them.  Yews are a snap to grow, unless an overactive irrigation system drags them down, and eventually drowns them.  Established landscape plants rarely need supplemental  irrigation, unless there is a drought.  Overwatered trees and shrubs will go yellow in leaf.  Hydrangeas appreciate a regular source of water-it takes a lot for them to produce prodigious blooms of great size.  Water them regularly.  Smart watering makes the difference between a passable landscape-and a stellar landscape.  Think through the wet and the dry-make a plan to endorse and follow that happy medium. 

Angie supervises one of my crews.  She is of the opinion that containers and plants should be watered first thing in the morning.  This gives them the entire day to soak up, to make use of,  that morning water.  Once dusk comes, the warmth of the day has already absorbed the the day’s watering.  The excess-so much steam.  This is a theory, remember.  This is a garden story that might make no sense scientifically, but could make emotional sense.  Dryer, overnight, given cooler temperatures-a good thing.  Good water during the day feeds the plants.  Dryer at night ensures their survival. I like my summer container plantings to go on into the fall.  Watching the water really carefully now will make a difference in their longevity.

 I usually water my containers after work-this is when I have time.  I load up the corgis at 6:15 most mornings-to go to work.  They fuss if I am late serving breakfast-they really fuss if we do not leave on time.  Given those dogs, I am not a morning waterer.  Tonight I find that all of my containers have just enough moisture to survive until morning.  If I water them tonight, they will be soaking wet in overnight chilly weather.  I make a call – no water tonight.  Tomorrow morning I will water-the corgis loaded up in the Suburban.  I will load them in the car, and water what really needs water.  

I read somewhere long ago that plants do most of their growing in the wee hours of the morning-meaning 4 until 6am.  It makes sense that their roots need to be able to breathe then.  My containers are the most water sensitive of any plants I grow.  As I am interested that they grow on into the fall, I am interested in testing Angie’s theory.  Water in the morning.  Make the daytime evaporation rate work in the interest of enabling  dryer and happier plants overnight-before morning. 

Every gardener needs to carefully observe how their plants react to their care.  Good observation makes for a really good garden.  Great gardens are unquestionably more about care than design.  Make every effort to get the water right.               






Too Much Water


I knew from the start that the installation of this landscape would prove difficult.  The property on the whole drains poorly at best.  The soil is very heavy clay; parts of the property would hold water for weeks in the spring.  It is not as if I were hoping for the best; an extensive drainage system was installed, and 1000 yards of soil added to bring the grade up.  Faintly visible above the boxwood in this picture, one of many catch basins.  The central landscape feature for the rear yard-14 very large columnar carpinus.  By very large, I mean in excess of 25 feet tall.  In front of those carpinus, densiformis yews and boxwood planted on a large radius.  A rose garden and fountain completed this center portion of the landscape.   

On either side of this center section, simple lawn panels edged in boxwood.  At the far ends, a pair of herbaceous borders on both sides of the lawn.  The wild landscape in the background would be left as is, although there were a number of ash trees dead and dying which had to come down. 

The perennial gardens are backed up by a long hedge of Limelight hydrangea.  The perennial border were planted with Russian sage, boltonia, peonies, Siberian iris, Shasta daisies, coneflowers-all the usual suspects.  I was interested in those perennials that are fairly easy to grow, and lots of them. I did plant the perennials alternating; that meadowy look would pair well with that untouched wild background. 

Within a year, the carpinus had begun to show definite signs of water stress. Roses and perennials, going into the winter soaking wet, died.  I suspected that the irrigation system was pumping as much water to all of the beds as it was to the lawn.  Once woody plant material is established, its need for water declines.  I was by no means thrilled with how the irrigation system had been designed, but it was what I had to work with.  The lawn looked fine-the landscape did not. 

By the third year, there was no mistaking that the trees were not going to tolerate the level of water they were getting.  Added to that, some hard late spring frosts with below freezing temperatures for 4 days in a row.  There were lots of leaf buds damaged or destroyed.  My client was alarmed by what she saw.  I told her there was no giving up on the trees.  We no longer had access to the rear yard to plant trees.  She was going to have to grow them out. My client is a very decisive individual.  She turned the irrigation off, and locked the box.  The lawn was irrigated as little as possible, and definitely not on any regular schedule.  

5 years later, the carpinus have made quite the comeback, and are growing vigorously.  They only get water when it rains.  All of the woody plant material has stabilized.  It can be very difficult to establish a landscape on clay, but once it is established it is very long lived-unless you overwater.  Enough water to live, and enough water to drown can be close to the same amount.  Once you see the foliage on woody plants start to yellow, check the water first.   

Even the yews behind the boxwood have stabilized  If you are wondering how it is possible for it to be shorter than the boxwood-the deer keep it pruned like this.  I am amazed at how level a job they do, chewing.   

The lawn has spots that look like they could use a little water, but a sustainable equilibrium here is more important than a perfect lawn.  The foliage color of every plant is exactly as it should be.  M and M maintains this landscape; Mindy keeps a sharp eye out for any sign of too much water.  It has taken 6 years to get this landscape to thrive as it should. 

Even the perennials have put on size.  I find it very easy to get perennials planted in sandy soil to take hold, but it is so hard to keep them thriving.  The only solution there is to add organic material to the soil and mulch every chance you get.  Perennial bark fines add a lot of organic material to the soil, when it decomposes.  Once perennials are well established on clay, they can live a long time. 

We have the watering on the pots down as well. One of the reasons I so enjoy container gardening is my option to pick the soil, and supply adequate drainage.  My experience planting indicates that attempting to radically change the composition of native soil is futile.  I plant trees that like wet feet in very heavy soils; I have success with evergreens and lavender on sandy based well drained soils.  I almost never plant rhododendron-our soil is very heavy and alkaline, not acid and compost based. But the pots are different-I get to pick the soil.  These yellow cannas are beginning to spike; they have had enough hot weather and regular watering to flower.   

This is a much happier garden than it was 6 years ago.  As Jennifer commented yesterday, a gardener is a person who is in it for the long haul.  These pot planting only last one season.  I like that.  I can start over, and do better next year.  But a  landscape is a committment that needs looking after, year after year.  

No sign of any trouble here today.