Surviving irrigation-free

Coleonema pulchrum, a commonly irrigated landscape plant,  growing irrigation-free in Oakland
Coleonema pulchrum, a commonly irrigated landscape plant, growing irrigation-free in Oakland

There are so many plants of the landscape that we assume are water-loving because they are never given a chance to prove otherwise, and because we don’t look into their native growing conditions to see just how little water they need to grow and thrive. Coleonema pulchrum is just such a plant. With its chartreuse leaves and pink flowers, it’s a much-loved plant in Northern California, offering a bright spot within what could be a washed-out landscape of dull greens and grays. Yet what folks probably don’t know is that this plant is native to a summer-dry, winter-wet region of South Africa and thus for many months out of the year has to tough it out with no water.

Indeed, even a drought-tolerant plant will need water up front in order to get established, but once established, the watering can be phased out, and the plant will thank you for it. Plants that are native to regions where drought is simply part of the climate oftentimes simply cannot absorb enough water from irrigation if they are watered during their period of dormancy as their root systems go into a sort of slumber during this time. In a worst-case scenario, their roots will rot, or the plant will grow much larger and faster than it should, ultimately opening out on itself and taking on a leggy appearance that no one particularly likes.

In our inveterate efforts to show that irrigation-free is all around us, we hope that folks will start to open their eyes to other plants they’ve seen growing irrigation-free and doing just fine.

When a forest isn’t a forest

A prairie savannah in what had recently been forest in Phil Hardberger Park, San Antonio, TX. Photo from the Phil Hardberger Park Conservancy.
A prairie savannah in what had once been forest in Phil Hardberger Park, San Antonio, TX. Photo from the Phil Hardberger Park Conservancy.

We so often think that forest is the natural result of just letting nature be and that to see forest is to see an indication of a healthy ecosystem. Yet we forget that many ecosystems are actually not forest-based at all, or else they are a mix of forest and other types of ecologies, such as grasslands and prairies. Years of fire suppression and mismanagement in the US have actually allowed many formerly grassland and savannah (mix of grassland and forest) ecologies to become completely dominated by forest, which is then often dominated by one or two species that have simply outcompeted everything else.

This scenario was very much the case within what is now Phil Hardberger Park in San Antonio. Years of fire suppression, grazing, and dairy ranching on the site had turned what had once been prairie, prairie savannah, and some forest, into basically all forest. So embedded had the forest look and feel of the area become that within the local narrative of the place people simply saw it as natural and having always been there. Recently, when the site was to be re-envisioned as a park, designers and ecologists had to contend with vast stands of juniper that had worked their way in and basically choked out native grasses, oaks, and perennials.

This foresting of places that were never forests to begin with is nothing new in American history. In fact, much of California was grassland before European settlers arrived. In his book, Trees in Paradise, Jared Farmer writes that settlers coming to the Far West wanted to “complete” the land by foresting it. “They forced grasslands and wetlands to metamorphose into fields, orchards, and garden cities,” he writes. To use a term of the time, they “emparadised” it. These longstanding efforts, combined with years of fire suppression, have transformed parts of California into hybrid manmade-natural tree-dominant ecologies that didn’t exist prior to the arrival of the Spanish some 450 years ago.

Of course, the lessons we can learn from these examples are not that trees don’t have their place in spaces where perhaps they once didn’t grow. Our urban and suburban landscapes are brimming with things that didn’t used to be there – pavement, right angles, roofs, to name a few – so to make the case that trees shouldn’t be there because they weren’t there before doesn’t really hold water. Not to mention that we need street trees more than even, given the realities of the urban heat island effect and climate change. Yet when it comes to our less urbanized and wilder spaces and places, rethinking the role of the tree in ecologies that were not ever forest is a much-needed endeavor. To restore these places back to prairie or Savannah is a way of ensuring that they are able to grow and evolve in a way that ultimately reaches a balance, so that one species – such as juniper – doesn’t become so dominant as to prevent biodiversity from flourishing. As a result, intense, long-term maintenance of the space does not have to be a prolonged and expensive reality.

Irrigation-free all around you

A Verbascum bombyciferum growing irrigation-free in an alleyway in Oakland, at the end of the dry season
Verbascum bombyciferum growing irrigation-free in an alleyway in Oakland, at the end of the dry season

When we say we do irrigation-free landscapes, we typically get one of three responses: 1. That can’t be done; 2. That’s been done before; or, 3. How cool. We love the third, of course, but the first and second responses do merit a conversation.

When it comes to the first, all it takes is a bit of observation just beyond your front door to see that there are plants growing irrigation-free all around us. The above photo is of a couple Verbascum bombyciferum plants growing totally irrigation free, at the tail end of the dry season in Oakland, California. And this isn’t the only one. We’ve seen canary palms, lavenders, four o’clocks, coleonemas, calla lilies, and more, growing irrigation-free and looking just fine.

Once we have seen and observed these lovely tough ones doing their thang, we should ask ourselves what we can learn from them, so that we might either use some of them in our own landscapes, or find ones better suited to the space in question and our aesthetic tastes but that have the same drought-busting qualities that these do.

As for the second response, the dismissive one of “Oh that’s been done before” – well, in part they are right. Nature has been doing irrigation-free for milllenia. Yet as far as actual gardeners, landscape designers, architects, contractors doing irrigation-free in more cultivated landscapes – especially in the US – we have seen very little of it. The drought training, the watering basins, the right plants, the rainwater harvesting, the monitoring of how much water each plant gets, all in one landscape – we’ve done this, yes, and very successfully in our pilot landscape. Brad Lancaster has done much with rainwater harvesting and contouring in his, and there is some truly forward-thinking stuff going on in Tucson. But we have seen little beyond this, especially in a place as supposedly forward-thinking and progressive as the Bay Area, where we are actually light years behind when it comes to both stormwater retention and truly drought-tolerant landscapes. Most of our rainwater ends up running into the Bay, and virtually all of our landscapes are tethered to irrigation systems – even the drought-tolerant ones. In other words, we have a long way to go. In any case, though, if it has been done, well, it couldn’t hurt the planet to have it be done much much more.

In the meantime, we as Prairieform will keep giving presentations on irrigation-free landscapes (most recently at the University of East London and UC Davis), make those landscapes a reality, and keep chugging forward, finding those folks whose response is refreshingly, “How cool.”

Rethinking the magnolia

Two dead magnolia trees in Alhambra, California. Victims of drought and a lack of foresight.
Two dead magnolia trees in Alhambra, California. Victims of drought and a lack of foresight.

While past peak, the years-long drought in California is showing its effects in slo-mo delay, coming on in the form of many a street tree stressed to the point of just not being able to take it anymore. Nowhere can this phenomenon be seen more than in Southern Calfifornia, where one of the street trees hardest hit has been the southern magnolia / Magnolia grandiflora. A tree native to the rain-abundant American South, it probably never should have been planted in Southern California at all, where rainfall is typically a scant 12 – 15″ during a good year. But, alas, like so many consumer goods, trees come in and out of fashion, regardless of what practical considerations there may be. So in the ’50s and ’60s street upon street were planted with magnolias in places like Hollywood, and Beverly Hills, and Alhambra – all arid regions and all requiring that the magnolias be irrigated generously in order to survive and thrive. So when the watering bans then hit a few years ago and folks were told to let their lawns and parkways go brown, the trees were never ready for the suddenly parched conditions. Many became stressed, and now, some years later, many are dying. As a result, the cooling shade and outdoor-room-creating canopies will be lost, and we will be left with wide streets and excessive sunlight and heat.

A jacaranda, cactus, and yuccas growing and thriving in hot Riverside County.
A jacaranda, cactus, and yuccas growing and thriving in hot Riverside County.

While devastating for the character of so many neighborhoods and the quality of life of our cities, we need to view this loss of trees as an opportunity to rethink what we plant and how. Even before the drought and worsening global warming, LA was a dry place. This simple truism is not going to change in the foreseeable future, and thus we must start planting trees that can handle these hotter and drier conditions – and that can handle them for the long haul. All it takes is a little observation to see which trees are still pushing on and looking good. In the photo above, you can see that this jacaranda – a tree actually not considered one of the most drought tolerant – and its surrounding plants are doing just fine – more than fine – and this is in hot hot Riverside County, in a parkway space surrounded by heat-absorbing asphalt and concrete. What other trees do you see still doing well? What other trees that you haven’t seen could be invited in, to create amazing tree-lined boulevards for the 21st century? Mesquites, acacias, jacarandas, palo verdes, tristanias – and the list goes on. We cannot keep doing what we’ve always done; it’s simply not working, and we’re seeing our lack of foresight in the form of sadly dying trees and sunbaked parkways. Let’s do better this time around.

We are now licensed landscape contractors

Photo of new Prairieform business cards featuring their new California Landscape Contractor license number.
New Prairieform business cards, complete with fancy license number

It’s o-fish, we have passed our exams, are fully bonded and insured, and are now licensed landscape contractors in the state of California. We started out mega-small in Minneapolis, working on my parents’ landscape, and from there things have grown and evolved and led to this. Our goal is to make irrigation-free a reality in California. People say it cannot be done, but we know it can, and the plants and water supplies will thank us for it.

-John Kamp