Showing posts with label Heat. Show all posts
Showing posts with label Heat. Show all posts

Wednesday, August 1, 2018

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


BEATING THE HEAT


·      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).




Links:


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
leaf-scorch.pdf
Extension Service | Leaf Scorch
8445.pdf
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) - GrowOrganic.com
Reserach-Summary_Cochran-Dissertation-MBI.pdf
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
https://cimis.water.ca.gov/

Saturday, July 7, 2018

7 Coolest Places at the Arboretum.


OK, when it's 117 it's too hot to go anywhere, however when the temps get back down to reasonable (max 102), here's some places to check out here and stay cool. 

Wednesday, July 19, 2017

What Is There To Do and See at the L.A. County Arboretum & Botanic Garden When it’s really Hot?

It’s Summer here at the Arboretum. This time of year can be hot -we just had some pretty healthy 105 degree plus days. Besides slathering on sunscreen, wearing cool clothing, carrying (and drinking) plenty of water and fluids,  and wearing a hat or carrying a sun blocking umbrella, what can you do to really enjoy your day here besides the usual survival 101 skills?

Plan to visit areas that are shady and cool!  We have compiled a list of the 7 coolest places in the Arboretum so that you don’t have to wait for cooler weather to visit. So here are the 7 coolest places in the Arboretum, from furthest to closest:

1. Meyberg Falls
2. The Historic Section
3. The Bamboo Grove
4. The Tropical Rainforest
5. The Tropical Greenhouse
6. The Celebration Garden
7. The Arboretum Library

Let’s take a look.

Meyberg Falls 


Meyberg Falls

On just about any day here at the Arboretum you can find a dozen or more people hanging out here. Besides visitors, it’s popular with wedding photographers, music video producers and feature film makers. Katy Perry’s ‘Roar’ Video, Beyonce’s ‘Survivor’ video and the Rock video scene in “Wayne’s World” were just some of the many that were filmed there.
Lucky Baldwin's Queen Anne Cottage


The Historic Section

When San Francisco hotelier and millionaire Lucky Baldwin decided to invest in property here in the L.A. area, the Santa Anita ranch was one of the first purchases he made. Lucky’s ranch was surrounded by dry communities, so alcohol, gaming and horse racing were regular activities. To raise his ranch’s status above that of a mere roadhouse he featured fine varietal wines, a first class hotel, and to attract a higher class of clientele, authors, actors, opera singers and other celebrities of the day as featured guests. These celebs would stay at Lucky’s Queen Anne Cottage and give lectures, recitals and concerts to attract the staid citizens of the surrounding towns.

This historic section of the Arboretum is planted with many large trees, many over 100 years old, that provide shade -and a large lawn that is popular with weddings and other events.

Shady path through a bamboo grove here. 

The Bamboo Grove

The Arboretum has many exemplary collections, including over 60 different species of bamboo. Some of these bamboo, like Phyllostachys aurea, have formed dense and shady groves where you can duck in and avoid the sun in a cool, green forests of the grassy plants. The interiors of these groves can resemble green caverns and they are very popular with videographers, photographers and artists. A word of warning; be careful of the many small, stake-like stumps that can pose a tripping hazard.
The Tropical Rainforest


The Tropical Rainforest

Situated on the North side of Baldwin lake, the Tropical Rainforest is an area that represents the forests of the tropics and subtropics. Situated under tall Cypress trees from the American South and Mexico, this shaded paradise contains a collection of cycads, a grove of bamboo, and a disparate collection of tropical trees from around the world. There are several benches located in the forest, making it the perfect place to sit down and relax.
Inside the Tropical Greenhouse


The Tropical Greenhouse


When the weather is boiling hot the Tropical Greenhouse, located to the North of the main entrance, is not. That’s because it is usually kept to a constant temperature somewhere around 85 degrees -a relative ice box when the temperature is hovering around 105. Inside are orchids, ferns, bromeliads and even a Cocoa tree, the source of chocolate.


Small courtyard fountain in the Demonstration Garden. 
Top of the Weeping Fountain in Lew Watanabe's meditation garden vignette in the Demonstration Garden. 

The Celebration Garden

This area is a cool collection of shaded ‘vignette’ gardens that used to make up the Sunset demonstration garden, an area originally envisioned in the envisioned as being a demonstration and an inspiration to do-it-yourself landscapers. It’s last refurbishing, back in 1998, featured vignettes from cutting edge landscape architects and designers. Still visible today are a shady lawn garden, a courtyard fountain garden, a low water use deck area that uses synthetic recycled deck elements, a California native garden that uses polished granite as a faux stream, a shaded walk among California coastal redwoods and Canary Island pines, and finally a traditional Japanese meditation garden fashioned by the late Sierra Madre garden designer Lew Watanabe. Lew’s garden contains an example of his signature ‘weeping wall’ fountains, granite sculptures that are painstakingly made level so that the water pumped out the top covers the top and side of the fountain with a thin film of flowing water.

The Arboretum Horticultural Library

The Arboretum Horticultural Library

One of the finest collections of horticultural and botanical texts on the west coast, it is also a fine example of mid-century modern architecture.

A recent remodel has rendered its interior space true to its mid-century roots. Come inside and see the newly revealed vaulted ceiling, true-to-period lamps and furniture and spacious, yet less claustrophobic book shelving. Say 'Hi' to myself and librarian Susan Eubank. And, most importantly, enjoy the massively effective air conditioning.

Map to the Above Locations



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