Hugelkultur and berms implemented to build healthy, reslient soil and capture additional rainwater.

Summer-Dry Blues

By Shawn Maestretti and Leigh Adams

What is the moment that incites panic into the heart of both landscape industry professionals and their clients?

The phone call, the text, the email, and the accompanying photos with the message that “something is wrong with my garden”. There are strange insects on the plants, some plants look like they are dying, and so on. This is extremely common during the first summer of a new, “summer-dry” garden just as the roots are establishing and making connections.

What does “summer-dry” mean? Great question! Southern California is the driest of the five Mediterranean-climate regions, the other four being Southwest Australia, South Africa, Central Chile, and of course, the Mediterranean. We get our rains in the winter and little to none for up to 9 months every year. That’s a long time without water. Many CA native plants go through a drought-dormancy phase which can sometimes look unattractive, but it is part of the natural process and should be considered during the plant selection step. In the face of water protection and scarcity, our goal must be to optimize our water use and one way to do that is to plant native and/or other climate-appropriate plants. This may come with a steep learning curve.

Clouded Sulphur butterfly laying eggs on Mound San Bruno Coffeeberry in June

Designers put their heart and soul into each project. Careful consideration for the site, the client’s wishes, and respect for the climate are just a few of the elements that help to shape professional design work. Many landscape architects and designers have shared with us that part of their love for the work is in the synthesis of science and art. When we are truly fortunate, we journey with our clients and their gardens from ‘concept to completion’ and hope that that will lead to an ongoing relationship that supports the development of the garden over time. In our case , that means placing some plants in the ground with nurturing thoughts and words and seeing the new garden thrive.

Case in point, I got an alarming text just a couple weeks ago regarding a new California native, regenerative garden that had been planted in the December 2018. A number of plants were suffering and undesirable insects were present, all documented with photos. So, what did I do? As the consummate professional, I went into a panic that this glorious garden was failing and I scheduled a site visit. On a Sunday afternoon, with my soil probe and camera in hand, I headed over to the garden in question with my dear colleague Leigh.

Did I mention that we had just had our first real heatwave of the Summer?  Yeah, it was hot for a while, really hot.  

Eriogonum grande rubescens, Arctostaphylos hookeri ‘Monterey Carpet’ and Festuca californica all establishing beautifully.

Upon walking into the garden, all we saw were healthy, vibrantly lush plantings of native plants, oh, and a few burnt, dead, wilting ones here and there.  Ok…deep breath…not anything close to what I had imagined it would be. We exchanged relieved glances and took photos before pulling out the tools to test the soil.

A few Coffeeberries planted along the brick path had some dried up stems…maybe casualties of the “edge-effect”; brick radiates heat and these damaged plants were in the perfect spot to capture both quickly drying edges and warmer surface.  Maybe something else?

A few Island Buckwheats with enormous, glorious blooms had wilting leaves. The plants were so happy it appeared they had used up most of their resources and sent up 2’ tall bloom stalks. Was this the result of too little or too much water? Maybe something else?

A few of the heucheras fried where they were getting more direct sunlight than expected. Others in the yummy, shady conditions had mealybug, but they seemed unaffected.  Recent rains and high humidity conspired together create perfect conditions for our six-legged friends. Some plants at the sidewalk’s edge were damaged and smelled like dog urine.  Maybe.

Of course, the most annoying, yet not-so-surprising is the death of a Ceanothus, California Lilac.  And the culprit? Phytophthora, a fungal root rot pathogen that is often spread via new plants from the nursery/grower, but its growth enhanced during the warmer months and moist conditions.  This could have been avoided if we had cut back on the water a month earlier, but we designers/contractors are always worried we may be underwatering the establishing garden. And so the take-home message regarding watering is: when in doubt, don’t! Plants can revive if underwatered unless they’ve dried out beyond the wilting point, but they rarely revive if their roots have rotted due to overwatering.

Sudden death of Ceanothus hearstorium on berm due to too much water during the very hot month of July.

View from under dead Ceanothus hearstorium showing signs of fungal root rot.

Heucheras showing stress from recent heatwave and too much sun.

Eriogonum grande rubescens wilting during heatwave and after a glorious bloom.

Perhaps this was a good reminder for all parties involved, designer, client and maintenance professionals:  when breaking from the norm and and planting a “summer-dry” garden, the first summer is always the hardest.  And this is particularly important if the plants were installed at the end of or after the rainy season has ended! When you see what looks like a problem (wilting, infestation, death, etc), before you take the “knee-jerk” reaction:

  1. Pause. Breathe. Maybe – I am saying this more for me.
  2. Step back and take in the context – Are other plants suffering too?
  3. Observe conditions – ex. Recent heatwave, overwatering, etc. Use a hydrometer so you KNOW the moisture level of the soil
  4. Inspect closely – check for damage, lesions, infestations and document what you see with photographs. The human mind is a trickster, photos can help support decisions, reminders and development of sound protocols.
  5. Then you can take action… even if it means no action 

“Maybe” is a powerful word.  It adds a pause and it is non-judgemental. It creates a space to look at the bigger picture.  Often times we jump to a conclusion that motivates us to “apply” a product that could end up harming beneficial organisms. 

Often the best approach is the simplest one. In the case of this garden, we observe.  Apply some diatomaceous earth for the Argentine ants and mealybug, reduce the water, and wait.  And, this is important, we don’t increase the watering because we are nurturing a resilient, summer-dry garden.  After the first summer you will have a good idea of how truly strong your garden is.

Losses in a new garden are inevitable…….in every new garden.  Plants take time to establish and build the “community” that supports them through living soil.  When we look at plants grown in pots, moved to a new location, inserted into a new environment and anxiously observed as weather changes, soil amendments are absorbed, watering schedules and sunlight exposure vary; it is actually a miracle that plants do grow and thrive. Though they will not be welcomed, some losses are inevitable.  Instead of grieving over the losses (and remember they are learning opportunities), we recommend that you celebrate the successes and give Nature credit for her extraordinary powers of regeneration.

We are most grateful to these Clients for understanding and accepting the process of nurturing a new garden into life.  This kind of understanding and collaboration is what it is all about. Patience is the most fundamental virtue in planting and nurturing a garden, so THANK YOU!

Regenerative landscapes take after natural systems, fostering underground communities from which they build on, relying on what the local climate offers, but most importantly, they can change the local climate.  SMGA specializes in these practices to help beat the heat island effect, capture rainwater for the landscape, nurture healthy soils and consistently implement practices taught by the land.

Signs of plant distress after a week long heatwave during the first summer of establishment.

Eriogonum grande rubescens, Arctostaphylos edmunsii ‘Carmel Sur’ and Festuca californica all establishing beautifully during the first summer.