2009-05-20

Notes from Native Plant Design Class

I went to the Native Plant Design Class on Saturday then over to Mark's house for dinner with his family. These are the notes that I took from the class. All errors are mine.

The instructor was Robert Cornell of RobertCornell.com. He was a Buddhist monk for 10 years and he currently has a spiritual therapy practice in addition to his landscape design business, so the class started off a little differently than most. He asked us to do some closed eye meditation and visualize aspects of a favorite native or garden environment. Then he asked us to bring the feelings that we had and "our connection to the earth - our island home, each other and spirit or 'god'" to our understanding of our love of gardens and our desire to do something positive for the earth.

With that done, he headed into an old fashioned slide show to showcase the garden design issues that he brought to the class. He made the point several times that he stays employed as a garden designer because he is responsive to his clients' needs, which inevitably involves compromise in the plant pallette selection compared to typical hardcore nativists. For example, if a plant looks dead because it has a summer dormancy, he is less likely to use it.

First on the slide show was an annual wetland area / dry stream at the Rancho Santa Ana Botanic Gardens. He recommended these gardens and the Santa Barbara botanic gardens as places to see native plants in their full glory. He made the point that the RSABG "annual wetland" was a created place, with artfully placed stones and a created topography that created a very effective illusion. The installation was pretty large, and he planned to show us progressively smaller installations as the slide show progressed. Attention was given to topography, drainage, exposure - both sun and wind, soil type and drainage, and existing native plants.

Next up was a large Brentwood residence that illustrated solutions for topography and drainage solutions. The solutions were hugely expensive because of the scale - nothing I could afford for myself but some I could conceive on a smaller scale, I suppose. One involved digging out 4' of fill dirt that the architect had put in and refilling with a special soil mixture, pipes for aeration of root systems, gravel for drainage, and adding a bridge over the now-reduced soil height.

He talked for some time about how he does irrigation. He uses a standard zone setup, with drip irrigation and high efficiency rotating sprinkler heads. The Rainbird style rotating head is apparently passe. You must use a rotating head with small droplets on hillsides so the water droplets have time to soak in and don't run off as a sheet. Rainbird-style sprinklers have large droplets that can contribute to erosion, are noisy, lose water out the back. Gear-driven MP Rotator brand sprinklers were mentioned with favor.

Drip irrigation is done with a style of drip like Netafim (a brand mentioned favorably). These drip systems have the emitters already built in to the hose (with variable drip rates and spacing up to 1 m apart) so there's no need for to punch holes and add spaghetti tubing or emitters (which always break). He puts the drip line on the surface, but under a layer of mulch and runs for 45 minutes or and hour which is 1 gallon per emitter. He suggested 1 watering per month for established drought resistant plants in summer. The drip is gridded on the surface you want to irrigate, with the emitters positioned so that they are not near the crowns of any natives. It's 12" to 16" between parallel drip grid lines. This sort of system seems like it would be good for my vegetable gardens, provided I had a water hookup nearby.

Many of the class attendees were exploring the idea of a native plant garden. A quote I liked: "The thing about natives is that if you have a control issue it'll be a problem."

Another quote followed the usual exhoratation to use groups of 3, 5, 7 or a single specimen, "No chop suey gardens!"

Fire was mentioned at length. The woman sitting next to me was interested in this topic. Robert presented a better way to site homes on hills at the urban / wild land interface, but or course no architect would implement it since it sacrifices views. He also recommended replacing chaparral with more fire-resistance plants. Lemonade Berry was given favorable mention as one that could be sheared low to prevent fire. Water systems are used to keep growth from being completely dried in the summer. Ultimately all fire prevention plans are unique to the site.

Next up was the house of Ed Begly, the environmentalist (notably not described as the actor or even actor-environmentalist). He has a yarrow meadow just like me! His looks better. It probably gets more water. I asked if he incorporated other plants in Ed's yarrow lawn and the answer was no, but he suggested bulbs and penstemon if I were to do that. Based on that recommendation, I put Penstemon 'Margarita BOP' into my own yarrow meadow later in the weekend. Ed's house is across from a school and not fenced - he does have a large number of Mahonia 'Skylark' at the edge of his property as an aid to privacy. It's a spiny plant and Robert suggested it under a window to prevent ingress or egress. Neater plants used in Ed's garden included Pacific Coast Iris and dwarf manzanita 'Emerald Carpet'.

A Mimulus or two was also used at the Begley house. Robert mentioned that they are a "touchy" native and need very little water. I'm sure now that is why mine have all died - too much water.

He mentioned Coreopsis perhaps with Gaillardia, as an example of non-natives that work with natives. Also Bulbine, a South African heather, that stays contained and small. He probably meant Bulbine frutescens, but he was often non-specific with his plant names. A plant list would have been a nice handout.

Summer Holly (Comarostaphylis) was mentioned as a good plant. I hadn't heard of it before, but it's out there on the web ref.

Buffalo grass, a N. American (but not California) native, was mentioned as a personal experiment of Robert's but today he says he wouldn't recommend it because of its long dormancy and sparse growth habit which allows easy weed intrusion. There's pictures on his web site. Of course the sparse growth habit and long winter dormancy would allow you to plant wildflowers or the like, so it seems like it's just that he doesn't recommend it to his clients.


A list of favorite garden plants (for garden designers who want to keep happy clients) list closed the informational part of the class:

Woodwardia fimbriata (Giant Chain Fern)
Salvia Spathacea (Hummingbird Sage)
Ribes viburnifolium foliage is scented - piney/resinous, evergreen, tolerates clay soils.
Summer Holly (Comarostaphylis)
Santa Ana cucurus (bad phonetic spelling, I guess - can't find anything with that spelling)
Carpenteria californica
Mahonia 'Golden Abundance' from Monrovia Nursery
Iris 'Canyon Snow' very strong
Erigeron (Coast Aster)
Coral Bells - 'canyon' hybrids
leymus 'Canyon Prince'
manzanita 'Howard McMinn' - best manzanita for yards. Slow grower. Winter bloom
Ceanothus
Western Redbud
Matilija Poppy- garden thug
Fremontodendron


He ended with a poem by Mary Oliver, "Some Questions You Might Ask" that was a bit zen. I don't usually go for meditation, but I left feeling relaxed and positive, so perhaps the internal looking parts of the class had the desired effect.

3 comments:

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  2. Thanks, Robert. I'm sure you're correct.

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