Friday, September 14, 2018

Celebration and Demonstration Garden Tour

Cantilevered patio in the old Sunset Demonstration Garden (photo by William Chrisman Aplin). 

Back in 1959 the L. A. Arboretum opened a landscape demonstration garden in conjunction with Sunset magazine.   Located just behind the administration building, it contained small, packaged idea gardens that helped inspire do-it-yourself homeowners. Here are some color photos of the garden taken in the 60's and 70's by William Chrisman Aplin, a photographer who worked for Sunset Magazine. It was designed with the help of some fairly well known landscape designers, including Edward Huntsman-Trout.

The Courtyard Garden in the demonstration garden, designed by Nick Williams. 

In 1998 Sunset Magazine funded a re-do of the Demonstration Garden. It was not so much an idea garden for do-it-yourselfers as it was a collection of well designed garden vignettes. It featured designs by several well known landscape designers.  Although Sunset Magazine no longer sponsors the garden (it has been renamed the 'Celebration Garden' and is used for parties and weddings, including the wedding of yours truly), it is still a beautiful destination and inspiration for both do-it-yourself gardeners and landscape designers.  One of the more compelling areas in the garden is the Meditation Garden designed by the late well known local garden designer Lew Watanabe. It features a weeping wall, a granite fountain that is comprised of rough granite blocks with a thin film of running water gently cascading down them.
Lew Watanabe's weeping wall fountain.

Take The Tour Here

Wednesday, September 5, 2018

Groundcover Lecture Notes

  • Groundcovers and Lawns Origins
    • The hungry hunter gatherer
      • Lawns represent prey nearby
      • Groundcover may represent food plants
      • Flowers represent fertility and water
    • Lawns
      • Also represent cattle and horse ownership
      • A cattle and horse owner looks out and sees the grass cut by the grazing of their animals.
      • Pasturage and Golf have propelled the lawn industry
        • Golf was first developed in China around AD 400
      • Lawn ownership and maintenance could be a form of:
        • Exercise in Dominance of territory (master of all you see with a weapon in hand to defend it), and target sport (warrior culture).
        • Increase in sight lines for security
    • Lawn Pros
      • Highly attractive, prestigious
      • Cool down the areas they are planted in.
      • Unequalled for athletic play
      • Huge subconscious satisfaction.
    • Lawn Cons
      • Huge amount of water
      • Require regular maintenance
      • Gas powered mowers are highly polluting.
      • Most of Southern California is naturally averse to lawns
      • Increased humidity
    • Types of Lawns
      • Summer dormant
        • Fescue
          • High water use but not as much as other summer dormant
          • Clumping
          • Susceptible to ‘melting out’
          • Aerate or Dethatch every several years.
          • Creeping red -California native good for shade
        • Bluegrass
          • High water use
          • Fine texture
          • Shallow roots -can dry out inland readily.
          • Disease susceptible
        • Bentgrass
          • Very high maintenance -putting green
          • Requires lots of water.
        • UC Verde Buffalo Grass
          • Winter and Summer dormant
          • Slow growing
          • Only really does well in the inland valleys.
          • Grows too slow on the coast.
        • Rye
          • Excellent regenerative properties.
          • Great for heavy use, athletic fields
          • Requires regular watering
      • Winter dormant
        • Bermuda
          • Low growing varieties make good putting greens
          • Fine textured
          • Go dormant in the winter: turf colorant best used as overseeding can be patchy
          • Best with regular dethatching
            • Dethatch in June here
          • Uses ½ the water that Fescue does.
        • St. Augustine
          • Luxuriant, old fashioned look
          • Less watering than fescue, more than bermuda
          • Needs dethatching once every 2-5 years
            • Dethatch in June, not Fall. Overseeding with rye not the best idea, instead consider turf colorant when it goes dormant.
            • You can prevent dormancy by applying high nitrogen in the late fall before it goes dormant, however you have to water more frequently.
        • Zoysia
          • Marketed as miracle grass on the back of newspaper Sunday circulars.
          • Long dormancy period makes it problematic for this area.
        • Paspalum
          • Great for salty conditions near the seashore; also for Palm Springs lawns.
          • Cool season dormancy almost as long as Zoysia, slow growing.
        • Kikuyu
          • The ‘Surrender’ lawn
          • Does not wear as well as bermuda, but can look just like it.
      • Lawn like groundcovers
        • Dichondra
          • Impossible to keep nowadays as the herbicide that allowed it to exist without hours of weekly weeding is off the market.
          • Still a great shade groundcover, as is its native cousin, Dichondra californica.
          • Related to yams and morning glories.
          • A sterile, low growing cultivar of  once popular water-saving California native ground cover Lippia nodiflora: Kurrapia can be grown and even mowed as a relatively low growing lawn AND purchased in easy to install rolls like sod.
        • Dymondia marguerite
          • Tough grey-green low growing groundcover for full sun.
          • Initial prep and establishment are important: dig amendment in to 8-12 inches the plant can develop deep roots.
          • After about 1-2 years of establishment you can cut the watering down gradually to once every two weeks.
          • Will take some traffic after established -however limit events and parties to once or twice a year -do not play football or ball sports on your Dymondia lawn.    
      • Specialty Mixes
        • Eco lawn
        • Patch Mixes
        • Shade mixes
      • Native grasses
        • Bouteloua
        • Festuca californica
        • Carex (praegracilis and tumulicola
    • Groundcovers
      • Perception that bare ground is infertile, sterile.
      • Fear of erosion
      • The concept of ground cover is relatively recent and may have been fueled by the Dust Bowls of the 1930’s.
  • Modern reasons for ground covers
    • Aesthetics, ground-cover provides a green area of continuity between larger landscape elements and plants.
    • Erosion control
      • Can prevent hillsides from sliding down if root structure is sufficient.
      • Must balance erosion control and fire prevention.
      • Some plants might actually increase breakdown of bedrock.
      • Always consult a soils geologist if there is a question of hillside failure
    • Security
      • Perceptively maintained and/or planted areas of landscape make people feel more secure.
      • Sightlines created by low groundcovers increase security.
  • Groundcover drawbacks
    • Water need is more than just bare ground.
    • Increased humidity.
    • Vermin and pests
      • Rats and Ivy
      • Midges and Red Apple
    • Discourage ground nesting bees.
    • Many require maintenance
      • Trimming
      • Cutting back
      • Fertilization
      • Thinning
    • Some can cause hillsides to come down.
      • Iceplant
      • Sedum
    • Selected Groundcovers
      • Iceplants
        • Aptenia (Red and Pink Apple)
        • Drosanthemum floribundum
        • Delosperma
        • Lampranthus
      • Sedum etc.
        • Sedum species
      • Asphodelaceae
        • Aloe ‘Red Riding Hood’
        • Creeping Aloes
      • Asteraceae
        • Gazania
        • Osteospermum
        • Dymondia
        • Achillea
      • Rosaceae
        • ‘Pink Carpet’ Roses
        • Other low growing roses
      • Lamiaceae
        • Rosemary
        • Salvia
        • Ajuga
        • Lippia
          • Kurapia (see above)
        • Thyme
        • Sage
      • Rhamnaceae
        • Cotoneaster
        • Ceanothus
      • Berberidaceae
        • Nandina
          • N. purpurea, N domestica dwarf (shade and sun)
        • Berberis repens (shade)
        • Ophiopogon japonicus nanus

Saturday, September 1, 2018

First Day of September Blooms at the L.A. Arboretum and Botanic Garden

Today was oddly cool and the plants here loved it. One really exciting plant to see right now is Puya berteroniana, the 'Turquoise Puya'. It has a rather unusual teal flower with orange anthers, a color combination rarely seen in nature. 
Puya berteroniana, the 'Turquoise Puya'

Puya berteroniana, the 'Turquoise Puya'

Puya berteroniana, the 'Turquoise Puya' closeup, notice the teal 'tepals' and the orange anthers. 
Also to the north of the Puya in the Water Conservation Garden are beautifully scented Sea Daffodils, Pancratium maritimum. These flowers are unusual in that they bloom in the summer or fall sans leaves, creating almost a ghostly look to them. However scary they may look, they make up for it in a very nice scent. They are native to the greater Mediterranean coastal areas and have become naturalized in parts of Southern California. 
Sea Daffodils, Pancratium maritimum. 
Ceiba (formerly Chorisia) speciosa var. 'September Splendor' is usually the first Floss silk to bloom in the fall. It was one of four seedling varieties of the species that were introduced for their ability to bloom in sequence from September to November. Here's a video I did that shows the differences between the four introductions. 
Ceiba (formerly Chorisia) speciosa var. 'September Splendor' 

Sunday, August 5, 2018

Keep an Eye Out for Summer Limb Drop

As the afternoons here get hotter and more humid it is the well irrigated trees that can become a threat. Summer limb drop affects trees like the Floss silk tree, The Italian stone pine, and other susceptible varieties. Here is a news interview I did on the subject several years ago after some children were injured by a falling pine tree :

Wednesday, August 1, 2018

Beating the Heat Lecture: How to Protect Your Plants in Record Temps


·      July 6th -119 degrees F for over an hour here.
Many Plants Scorched.
In the following days trees, shrubs and woody plants start to defoliate.

The Physiology of Heat Damage
·         PWP -mostly a problem with herbaceous plants.
·         Chloroplast damage -sets off a chain reaction in the plant.
o   Increased production of protective proteins
o   Increased production of abscission hormones.
o   Increased production of damaging peroxides.
·         Leaf drop
·         Fruit drop
·         Flower drop
·         Twig drop
·         Leaf scorch
·         Trunk and branch scorch (citrus and avocados)
·         Limb drop in susceptible trees.
What to Do After
·         Mulch
·         Increase irrigation frequency (but do not overirrigate)
·         Do not fertilize
·         Do not overwater
What if More Heat is on the Way?
·         Anti-transpirants?
o   Work by either plugging up the stomata or causing it to close.
o   Can cause overheating, decrease transpiration.
o   Work best in frost situations
·         Misters
o   Are expensive
o   Can cause fungal infestations
o   Require installation and $
o   Cheap barrel misters may be the best bet.
·         Shade-cloth
o   Can injure plants if just ‘draped’ on.
o   Should be installed as a permanent structure.
o   Need to choose right % for the plant.
o   Do not prevent all heat damage.
·         Kaolin
o   Sprays on
o   Helps control some insects as well
o   Irrigation washes it off.
o   Looks terrible.
·         Modify Irrigation
o   Check Evapotranspiration Index
o   Water according to current ET number.
§  Make sure you do irrigation measurement before you do this.
o   Use coffee cups and turn irrigation on for 10 minutes, measure depth in inches.
·         Plant Choices
o   Plants with blue-green coating (glaucous) do well.
o   Plants from South Africa and Madagascar do well.
o   Plants form the Southwest, South and Central America (not all).
o   Many (not all) Australian plants.
o   Plants from temperate areas do not usually do well.
·         Landscape Choices
o   Remember to put heat and sun resistant plants near walls and walks.
o   Go with climate appropriate plants.
o   Build shade structures.
o   Consider a mist system (for you, not the plants).


Scorch, Sunburn, and Heat Stress
Plant tolerance to high temperature in a changing environment: scientific fundamentals and production of heat stress-tolerant crops
When it is too hot for photosynthesis: heat-induced instability of photosynthesis in relation to respiratory burst, cell permeability changes and H2O2 formation
Leaf scorch | The Morton Arboretum
Sunburnt plants 'myth' is debunked - Telegraph
Extension Service | Leaf Scorch
Bacterial Scorch of Trees
Leaf scorch | The Morton Arboretum
Bacterial Leaf Scorch
Homemade Whitewash for Trees
Whitewashing an Avocado Tree
UC IPM: UC Management Guidelines for Sunburn on Avocado
Surround WP (25 Lb) -
How to prune heat damaged foliage
Impacts of Kaolin and Pinoline foliar application on growth, yield and water use efficiency of tomato (Solanum lycopersicum L.) grown under water deficit: A comparative study