Tuesday, May 21, 2013

Engelmann Oak (Quercus engelmannii) an Often Ignored Native in the Landscape

Credit: Jose C Juarez
I admire many Oak species for various individual characteristic reasons. But one that I've always admired for it's ability to grow in the harshest of conditions from a plant stand point is Engelmann Oak (Qurecus engelmannii). While there are many photos out there showing a luxuriant example in an ideal location in the sense of habitat, soil and water availability which make such a majestic photo opp such a prize, it's the other examples that impress me far more. I'm talking about the ability of this Oak to growing to large stature on a steep southern exposed slope. This speaks volumes to me as to this Oak's toughness under harsh extremes and a hot dry southern mountain slope doesn't get any more extreme than that. Now that's in the backcountry of a rural area of the southwest which has some of the nasty conditions imaginable for plants to survive and yet Engelmann Oaks thrive here. This makes an urban landscape environment an ideal paradise by comparison, where such plants should thrive under the loving care of a gardener or Landscaper. One of the best areas to observe prime examples of Engelmann in the wild beating the odds of a typical nasty drought condition habitat is at the Santa Ysabel Open Space Preserve. The sign above is west of Santa Ysabel and east of Witch Creek (area of the infamous 2007 fire). Below are some photos I took when I first arrived at the beginning of April on my way to Ranchita CA.

Credit Intermountain Fire and Rescue, Hwy 78, Ramona CA
This location with the hill behind it is a great starting point to view Engelmann Oak in a dry hot location on a southern slope. This is also an area ravaged by another infamous megafire named the  2007 Witch Creek Fire which swept through the area. It is location directly across from the well known Pine Hills Egg Ranch. The following photo is just to the east of this shot.

Credit: Mine
This picture is facing a southern slope in a usually dry hot location in the San Diego backcountry where most plants fail other than low growing coastal scrub Sages and Buchwheats. And yet we find large specimens of Engelmann Oak not only making this their home, but actually thriving on such plant impossible locations.

Credit: Mine
Santa Ysabel Creek is just beyond the foreground grassland hill with the Engelmann Oak covered mountain as the background. The gray coloured shrubs between the Oak Trees are actually a very low growing White Sage (Salvia apiana) and some small shrubby Silver Sagebrush (Artemisia cana). Interestingly the chaparral here facilitates the grow of this tree's acorns for which the Western Scrub Jay is the landscape designer.

Photo: Mine

This is looking directly east from the eastern portion of the Santa Ysabel Preserve entrance on Hwy 79 north of Santa Ysabel itself. While in this picture there may be one or two other trees like Interior Live Oak (Quercus wislizeni), but it is mostly the tough Engelmann Oak trees which dominates here.
Okay shifting some gears here for a bit on or in another area of San Diego County and subject of viewing these trees. One of the most remarkable things I like specifically about these Oak Trees when comparing them to other Oaks is their ability to self prune themselves into twisted picturesque shapes and/or forms. The California Sycamore also has an amazing ability to twist and shape itself and much of this is environmental and no doubt the same with the Engelmann Oak. Cal-Sycamores are influenced by what is called Anthracnose Canker which effects newer leaves causing side shoots to become the new leader bud which often may grow in a different direction than the original. Often this may even cause quite a bit of leaf drop, but I've never noticed this to be fatal to the tree. The result really is the picturesque contorted or twisted features for which they are known. In the shaping of the Engelmann Oak, they are drought-stress deciduous which may account for their amazing ability to survive where the other oaks will not. It also may allow them to not only drop leaves, but perhaps also twigs and even small branches giving it, it's often picturesque shapes. For me the best place for viewing these almost tropical picturesque shapes was on the switched back grade on Hwy 76 between the Junction of the Valley Center Road and the Oak Knoll Campground on the La Jolla Indian Reservation. This has always had some of the most beautiful forms of Engelmann Oak I've ever seen. I haven't visited there this time as I've had a lot on my photo shoot plate, but I'm not sure of their condition after that 2007 Poomacha Fire which burned at the same time as other notorious fires back then like 2007 Witch Creek Fire. Still I'm curious as to what these areas look like since the region was almost pure Engelmann Oak woodlands

Shifting gears again, I have another interesting note about the Engelmann Oak's acorn germination. In the early/middle 1970s, much of the literature I first found on acorn germination mentioned an interesting phenomena noted with one oak, the Gambel (Quercus gambelii) in particular which when it dropped it's acorns, the acorn germinated immediately upon to toughing the ground. With many acorns Scrub Jays often collect and bury acorns and germination under a favourite chaparral commences. With the Gambel it made sense because of the heavy monsoonal rains which are prevalent in it's range in Colorado, Utah, New Mexico and Arizona. But during the 1980s wet monsoonal seasons I also saw the same germination effect with Engelmann Oak as with Gambel Oaks. Below is a photo of just the exact tree where I first saw this phenomena. It is a single Engelmann Oak along Hwy 79 across from the Old Schoolhouse Road turnoff on Santa Ysabel Indian Reservation in San Diego Co. Below is a picture of that very oak i stopped at to collect acorns for germination at my home in Anza California.

Photo: Mine
This oak tree was always beautiful and I considered it easy access for collecting acorns in the early 1980s. What a surprise to find most all of them germinating under the vicinity of this parent tree. That summer was extremely wet and the grasslands were all a rich green. The soils in the Fall were still damp from Summer Monsoons. Notice to the left of the tree the smaller younger Engelmann Oak ? This is one of those offspring. Below is a close up of that younger tree.

Photo: Mine 
Here is one of those young trees that made it. There were many others, but as checks and balances circumstances dictate, only a few can make it to maturity. Such a beautiful healthy tree and I highly doubt commuters and tourists ever give it a second look or even know of it's early on history of germination.

Photo Mine
This is another much younger oak located on the north side of the parent tree. Notice the  chocking foxtail grasses and then the scene where I've pulled them away from the tree. Invasive non-native weeds are a hindrance to regeneration and no amount of control or prescribed burn is going to increase this trees numbers. Any burning would also destroy any seedling or saplings like the one below.

In conclusion I just have to say that I love these trees within the chaparral plant community because they are truly chaparral plant friendly. Unlike other oaks with dense shady foliage, these allow filtered light to enter under their canopy. Torrey Pines for me are another favourite to landscape with because they also are chaparral friendly, not overly dense allowing light to enter and reach low growing chaparral plants under them. This makes them perfect for urban landscapes for home owners, commercial landscapes and Municipal Park Projects. Unfortunately I have not seen enough of them in the cities, although I have seen them used in some places. Mostly the darker green Coast Live Oak gets favour because of it's dark greener foliage. Maybe the Engelmann Oak is overlooked because it has a bit of a bluegreen look which is not desired. Either way, landscapers are missing out and more field work by observing them in picturesque natural settings are what is needed for inspiration. At my mum's place when I first arrived I hit Las Pilitas Nursery north of Escondido CA along old Hwy 395 across from Champagne Lakes Campground and purchased a one gallon Engelmann Oak, planted it and have been excitedly watching it perform so well. In planting this and any other Cal Native plant (actually any plant period) DO NOT amend the soil ever. Simply loosen the soil around the sterile soil hole and heavily incorporate a blended multiple species mycorrhizal inoculum and water. Apply generous amounts of clean wood chip mulch on top of the soil and leave it alone. This should be the simple money saving rule with everything you plant. Once colonized with beneficial organisms, then NO FERTILIZERS should EVER be used. Do it and you'll lose everything. When you go to your local Home Depot or Lowe's, resist the plant junk food aisle with all the chemicals. Some of you people have been so indoctrinated into the conventional almost epigenetic mindset of traditional landscaping that you actually need deprogramming and just simply don't know it yet. Below I'll post some great links for self-deprogramming *smile*

On a side note, most of the studies literature has suggested there is fossil evidence that Engelmann Oak was widespread during wetter time periods across the Mojave and Sonoran Deserts. I don't this for an instant since I am already fascinated with ancient wetter times anyway. Oaks like Maples which are given the title "Cloud Trees", are major cloud producing trees because of their great ability to produces large quantities of aerosols for water droplet nuclei formation in clouds and I have no doubt among other missing mechanisms that they played major roles in wetter summer monsoons. This is where I wonder about such a role during the days of ancient Lake Cahuilla. I have a future post on the vast oak woodlands of Anza Valley coming up soon. Humans have disrespected and butchered their environment for centuries. In times past the greed and selfishness while inexcusable was also coupled with ignorance on natural ecosystem functions. There is no such ignorance today, so the deliberate irresponsible behavior makes modern humans more accountable and it starts with leadership whether Political, Business(Science) or Religious. These three entities are killing this planet and their bloodguilt is heavier. We may live in a time of resentment towards accountability, but that doesn't by any means change the accountability. People who willfully support such irresponsible leadership also bare a measure of the fault. There's no ideological pointing the fingers at one's opponents on this one. 

Before I leave California, I'll publish the photos and progress of my mum's front yard Engelmann Oak which suddenly is showing a rapid healthy growth. Just wish I could see the end of the year's results. Note to Mary Ann Kiger and Jerry Thornton, that hill you mentioned and showed me last week which was bare from the fire at the southwestern corner of your property would be an excellent spot to try these oaks. 
Further reading Material:
Santa Ysabel Open Space Preserve map
County of San Diego: Santa Ysabel Preserves
100 Peaks.com - "Santa Ysabel Open Space Preserve West"
http://www.pacifichorticulture.org - Engelmann Oak
Landscape Deprogramming courses & tools below>

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