Growing Plants in the High Desert- Early Experiences (part 1)
By Geoff Stein (palmbob) June 6, 2013
What is the high desert? That is a desert-like climate (arid mostly) but at an elevation that involves several climate extremes not normally associated with most 'lowland' deserts. In the United States, the high deserts are those found in parts of New Mexico, Arizona, Colorado, Utah, Nevada and Southern California. The latter two are lumped into the Sunset Climate zone 11 while the rest are relegated to the even more forbidding zone 10 (one of the most limited zones in terms of plants that can grow there). Either way, if one thumbs through the Sunset Western Garden book looking for what plants grow in which zones, one starts to realize almost nothing grows in zone 10 or 11 (relatively). Over and over I would run across a plant I thought was hardy that would grow in zones 2 or 3-9, or 4-9 and 12-20 etc., leaving out zone 1 (your basic tundra zone) and zones 10 and 11 (the high deserts). The growing season for these zones is remarkably limited (being accustomed to the year-round growing zone of my lower elevation climate home). The high desert zones are known for their extremes, both hot and cold, but also super arid and incredibly windy. And the general vegetation is typified by an overall brown color seen to your right in that little photo.
I grew up in New Mexico, in the mountains just above the high desert regions. We had a growing season that seemed to be about a month long- it snowed as late as June and sometimes started again in September. Though much of New Mexico is blessed with a myriad of wimpy wildflowers, conifers and scrubby, evil yuccas and cacti, there is not much else of note that grows there (compared to what I used to grow just outside of Los Angeles). The 'good thing' about zone 10 deserts (like those in New Mexico) is the high temperature extremes are not that high.... so a number of plants that do not tolerate blasting heat (like many conifers) can grow there. Though at the time, the ability to grow heat intolerant plants meant nothing to me, I did appreciate the cooler highs and took advantage by hiking the deserts all summer long. Zone 11 is not so blessed with a temperature ceiling- here 'hell' is the limit and there is always the posibility of setting an new 'blazing record' thanks to our focal global warming.
But now I have been put in the difficult position of moving down a few growing zones ('backsliding', 'regressing', 'devolving', 'plummeting' etc. is what it is called when a plant nut moves in the wrong direction, into a less hospitible growing zone). Basically it is taking someone with an incurable, compulsive-obsessive habit and forcing him to quit without the benefit of a rehab clinic or mood-altering drugs. It leaves me in a constant state of craving and frustration. I dream longingly of my old New Mexico days when I had no clue what a palm was, or the wonder of a great plant sale. Life was so much simpler back in those days. This move, surprisingly enough, still leaves me within the confines of Los Angeles County, a mere thirty miles inland from the coast. As one drives up the steep grade leaving Los Angeles, even the first twenty miles are peppered with endless plantings of King Palms, Bougainvillea, lush lawns and shady greenery everywhere. It isn't until one continues up the last ten miles to this current detination that one sees the typical grey and brown landscape as far as the eye can see, with a dull green Juniper dotting the barren landscape here and there. If one decides for some bizarre reason to keep going another ten miles they will get to the lush, tropical oasis (ha!) known as Palmdale.... why would anyone name a place Palmdale when almost all palms planted there look like they are always on the verge of extinction? Either way, it is certainly NOT an oasis. Just another 10 miles gets one into the Mojave Desert known for its remarkable lack of nearly all vegetation (ok, slight exaggeration there). If there is one good thing I can say about where I live, it isn't Palmdale.
fried palms wtih only a bit of green left in them in Palmdale this March
The climate here is one of those unusual geographic situations in which the seasons 'Spring' and 'Autumn' get left out. It moves from winter to summer here, sometimes overnight, and often back and forth with alarming ferocity during those particular months that in other areas of the county are called Spring or Autumn. During these transition seasons, the days are often blazing hot and the nights are freezing... or not. Sometimes it's bitter cold all day long, or sweltering all night, and the exact opposite a few days later. It's just the sort of climate most plants love, right?
snow on property in March (left); view from property of mostly dead-like native vegetation as far as the eye can see.. and this is the 'lush' time of year!
But one thing is certainly constant. It's DRY and very, very WINDY. And the wind is often 24 hours a day and often over fifty miles per hour. It's usually too windy to fly kites... maybe perfect for trying to fly a picnic table, wooden fence or a huge cloud of dust.... not much entertainment in this sort of wind. ALL the wind heading to and from Los Angeles and the Mojave desert passes through our dinky pass (aka wind tunnel)... and our property, though blessed with amazing 360 views, is right at the 'jet stream' altitude. An umbrella tossed into the air from our back yard would most like end up in some jet engine turbine, or in orbit, or at least make it a good distance around the world. Attempting to dry clothes on a clothes line in this town usually gets one a littering citation. Dragging ones feet along a carpet and touching another object can easily result in a brush fire in the next town just a few minutes later (a law had to be passed against static electricity in this climate). OK... maybe I exaggerate a wee bit again... but it IS really windy!
Newly planted palm from Tarzana being whipped in all directions (north wind left; south wind middle and east wind right, all within 24 hours
And it's dry, dry DRY! The humidity encroaches upon a negative number if that is possible. The formation of steam is not possible in this climate. Watering is typically done by drip as sprinkler water is just carried off into the atmosphere. So the combined effect of the constant gale force winds and the zero percent relative humidity results in the near complete and total dessication of all life. The result is a never-ending supply of tumbleweeds and that lush sandy brown color of the surrounding hillsides. I think the tumbleweed is our official wild flower. One buys skin lotion by the gallon here.
View of tumbleweeds and rabbitbush (Chamisa) surrounding property
The soil is another 'perk' of living in the high desert. It has less nutrients than beach sand or concrete, only with half the moisture. And one cannot dig a hole more than six inches deep without dynamite, or at least an iron digging bar to tunnel through the myriad of endless rocks, or bedrock. Most of the soil in my backyard is just like decomposed granite, only it hasn't gotten to the decomposition phase yet. Yet despite the preponderance of igneous rock in most holes I attempt to dig, all water is immediately sucked into a vacuum-like void, with any dampness that might have resulted from watering already just a distant memory. Plants that can survive here bring the definition of drought tolerant to a whole 'nother level. This is one of the main reasons native vegetation is basically dead for eleven and a half months, only to green, bloom, seed and wilt during that week or two it actually tries to rain (or snow) here. Most local residents have heard of the term 'mud' but never live to see any of it actually exist.
several non-native plants already on property dying before my eyes (both gone now) due to dessication. Rare super-drought tolerant plant in sand right (Joshua Tree- Yucca brevifolia)... rare greenery in a world of browns and beiges
The atmosphere here is also unique, thanks to abnormally high levels of ozone depleting substances in the atmosphere (Palmdale toxicants, primarily, but the weekly, massive dust clouds that get blown into the stratosphere don't help either). Either way, the result is a relative 'hole' in the ozone layer over the high desert that results in sublethal levels of ultraviolet radiation. It does make for a fairly sterile, disease-free ambient air quality, but it is remarkably brutal to human flesh. Just a few unprotected moments in the sunlight here usually results in a third degree sunburn. Like skin lotion, most SPF 100 sun screen is sold in bulk. Still, most are recommended to stay indoors after 7AM until about an hour after dark (and even starlight here can result in a nasty burn thanks to the lack of ozone). Most gardening is done by flashlight on cloudy or moonless nights.
Cycad leaves and and Aloe peglare (right) fried by sun, despite all living in full sun in the valley before the move- desert sun is brutal stuff!
The lack of ozone seems to be similarly hard on plants, or at least those that have not 'grown up' here. Almost every plant I have driven up here from the relative safety of the smoggy climate of Los Angeles immediately goes through an adaptive 'frying' period during which time anything green colored on the plant quickly turns to a brown, black or a sickly, chlorophyl-free yellow. Recovery is slow or not at all, but I cannot comment on the time needed to recover as I have not lived here long enough to see it happen.
Surprisingly this area is teeming with its own forms of life (non-floral) with the primary species on our property being gophers, rabbits and ground squirrels. If that isn't every plant's dreamscape, there are also a lot of large, hairy spiders, flies (thanks to surrounding livestock-infested properties), rattlesnakes and scorpions for our own pleasure and entertainment. Who wouldn't want to move here to grow plants??! Who would have thought this sort of paradise existed in Southern California at all, not to mention in the county of Los Angeles?
local inhabitants in my yard (lizards are abundant and I love them, but the other two above are a bit less welcome, though I have done nothing to dissuade them, either- they were here before I was)
So we moved here this 'winter-summer' transition period (March), the same time of year it begins to warm up in Los Angeles. I made the stupid mistake of deciding to move up some of my hardier plants with me at the time, not fully grasping the brutality of the local weather conditions (just because it's warming up on that end of Los Angeles county means nothing at this end of the county). It snowed the next day. Not enough snow to do anything fun like ski, make a snowman or skid around in a car with bald tires... but enough to kill off anything floral not already used to growing here. Then the sun, wind, heat/cold flip-flop, dessicating soil and hurricane-force winds picked the bones clean of those plants that the snowfall did not kill off.
Aloe cameronii (NOT a hardy species) did fine in winters in the valley, but melted overnight at my new home (before, left, after, right)
This was a more hardy example- an Agave potatorum hybrid, that did great for years in Los Angeles... melted in a few days at the high desert inn...
Needless to say there are not many survivors of my first plant-pilgrims to this high desert new world of mine. Subsequent voyages have been a tad more successful as the weather here has stabilized a bit into a constant but random revolving hot-cool cycle (vast improvement over the hot- freezing cold cycle), but the vicious winds, unfiltered sun and lack of measurable humidity still keep adding victims to their long list of successful floral assasinations. Still, I keep on trying since any plants I leave behind or don't give away are likely to be bulldozed by the subsequent home owner. So what have I got to lose (aside from my entire collection)? I guess I could just buy a case of marshmellows and burn all the remaining plants in the San Fernando Valley... but they burn WAY easier once they get here in the high desert and have all their moisture sucked out of them. I tried to get a burn permit recently and was declined, due to the high winds (which are year round... guess no burn permits ever?)
area of brush I have to clear to keep the fire department happy (and our house safe)- left; right is shot of our dinky trash bin I am supposed to throw mountains of dead brush into... will take me years to fit it all in!
No! I refuse to give up... I may just discover a few rare success stories and be the first human to grow this or that green plant species in the relatively sterile, lifeless brown/tan of the high desert. Wish me luck!!