Transcript Introduction to High Desert Gardening

SaddleBrooke/SaddleBrooke Ranch Master Gardeners
present:
Introduction to High Desert
Gardening
Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30,
1914, in cooperation with the U.S. Department of Agriculture, Jeffrey C.
Silvertooth, Associate Dean & Director, Economic Development & Extension,
College of Agriculture and Life Sciences, The University of Arizona.
The University of Arizona is an equal opportunity, affirmative action institution.
The University does not discriminate on the basis of race, color, religion, sex,
national origin, age, disability, veteran status, or sexual orientation in its
programs and activities.
1
INTRODUCTION TO HIGH
DESERT GARDENING
Charla M. Blacker
Master Gardener Intern
Arizona’s Five Seasons and Their Impact on
Landscapes
•Spring: warm and dry
• Fore-summer:
• May & June
• Very hot and dry
•Summer Monsoons
• July to mid September
• Major growing season
•Fall: warm and dry
•Winter: rain is more widespread but not as
intense as the monsoon season
What are Cold Hardiness Zones and What do
they mean to ME??
Saddlebrooke Ranch Can Get as Low as 15o F
with Resulting Risk of Freeze Damage
We Have Extreme Temperature Fluctuation!!
•Saddlebrooke Ranch- 120 days per year when
the temperature exceeds 86 o F
• The average annual high temperature is 76o F
• The average high temperature in July is 91o F, while
the average high temperature in January is 58o F
•Average minimum temps
• The average low temperature is 49o F, but in July
average is 67o F, while in January it is 35o F
•While the region averages 3-12” of rain yearly,
the Ranch averages about 19”
Protecting Your Plants from Cold
• Choose plants appropriate to this zone
• Select an appropriate site:
• Plant less hardy plants on the north, northeast, or eastern
side of the building
• Avoid low spots- frost pockets
• Follow recommended cultural practices: healthy
plants are less susceptible to winter injury
• Prune properly:
• Avoid late summer pruning
• Remove narrow branch angles that may break in heavy
snows
Using Frost Cloth to Protect Plants
• Cover plants at night to trap
radiant heat- this must go
all the way to the ground!
And don’t use plastic!
• Frost cloth is specifically
made to protect and can be left on for several days
• Place an incandescent light low inside the canopy; be careful
not to burn the trunk- old fashioned Christmas lights work
well
• Wrapping trunks with burlap can prevent bark splitting
Protecting Your Cacti
• The top of the cactus is the growing
point and must be protected
• Styrofoam works well
• Do not use plastic cups
Protect Against Cold Damage
•Windbreaks of burlap, canvas, etc. can provide
both protection from winter winds and shade
in summer
•Water properly:
• Deep soaking will supply water before ground
freezes
• Water during warm days
• Mulch can reduce alternate freezing and thawing
•A fine, gentle, continuous spray of water can
provide protection as low as 20 o F- must be
started when temperature is 34 o F and
continued until all ice has melted off the plant
Heat/Sunshine Care Takes Planning
• Native plants often are heat
loving
• Choose appropriate location for
heat sensitive plants
• Prune dead foliage and sucker
sprouts
• Remove weeds
Heat/Sun Care Takes Water
• Check soil moisture. Additional
water is usually required:
decreased interval, not duration
• Water early in the morning to
avoid excessive evaporation
• Mulch: helps to maintain water
in soil and also protects roots
from the sun- organics vs rocks
Providing Shade for Hot Gardens
• Provide shade- must be several
inches above plants
• Shade cloth
• Scavenged items- window screens,
lattice, sheets
• Decorative items can be use to
create shade for a single plant
within a pot
• Taller plants can shade younger,
shorter plants
Helpful Tools for Arizona Gardening
• Soften your ground before digging
with H2O!!
• Standard gardening tools +:
• Water gauge
• Soil probe
• Mattock
• Grasper
• Shade cloth
• Frost cloth
Irrigation Systems: Your Best Friend Even in
Zeroscaped Gardens
• Choose what needs to be irrigated
• Native plants do not require irrigation
(but may benefit for 6-12 months after
planting and during excessive heat)
• Irrigate by zone- separate deep
rooted, low water use from high
water use
• Trees
• Shrubs
• Vegetables & flowers
• Pots
• Cacti
Why Consider a Drip System (or Why Was it
Installed)?
•Drip irrigation uses a low volume of water
•Drip irrigation maintains constant moisture
around roots
•Drip irrigation applies water accurately to
where it is needed
•Drip irrigation cuts down on water loss to
evaporation
•Drip irrigation can be easily adjusted to
accommodate new plantings or reduce the
watering of older plantings
Irrigation System Layout
• Valve boxes- require cleaning
periodically
• Sprinklers, drip emitters,
drip tubing or bubblers:
• Choice of type of emitter
dependent upon what is planted
• Spacing of emitters based on
root zone: place emitters along a
plant’s dripline
• Controller (time clock)
• KNOW WHERE YOUR WATER
TURNOFF IS LOCATED
What You Need to Know
•How many valves are in my system?
•Can I control each valve without calling a
landscaper?
•How many gallons per hour do my emitters
release? (standard is 1 gallon per hour)
•How deeply do I need to water?
•What valves control what? i.e. are shrubs and
trees and citrus on the same valve?
•Other than flower and vegetable gardens and
pots, daily water is unnecessary
Understanding the Settings on Your Irrigation
System
• Digital vs analog
• Start time
• Run time
• Interval
• By day
• Odd, even
• Interval watering: 3-30 days
• Recheck settings after
power outages and make
sure battery is charged
so you don’t lose settings
• Rain gauge- you don’t need one if you can remember to shut
off/restart system
Timers are NOT Scary- and They Are All the
Same!
•Find the clock and set the time of day
•Find where the battery is stored, and insert a
battery so you won’t lose your settings
•Valves are located within “programs”: A, B, C
•The dial is for finding each valve: #1, #2, etc.,
and setting the valve run time
•You can select which days to run each valve
•You can manually run any valve
How Deep Should You Water?
The 1-2-3 Rule
• Small plants such as groundcovers, cacti, &
annuals to a depth of 1 foot
• Medium plants such as shrubs- 2 feet
• Trees: water to a depth of 3 feet
• Mesquite, Palo Verde usually do not require irrigation
• Citrus- water to 3 foot
• Measure the depth of irrigation with your probe!!
• If it rains, back off on irrigation interval not
duration
When to Water
•Water in the early morning- about 3 hours
before sunrise to avoid evaporation to the sun
and wind
•Frequency of Watering Suggestions:
Spring
Summer
Fall
Winter
Trees
7-12 days
7-10 days
7-12 days
14-30 days
Shrubs
7-10 days
5-7 days
7-10 days
10-14 days
Groundcovers/
Vines
7-10 days
5-7 days
7-10 days
10-14 days
Cacti/Succulents
21-45 days
14-30 days 21-45 days
If needed
Annuals
3-7 days
2-5 days
5-10 days
3-7 days
When to Start & Stop Irrigation
• Most new plants need some irrigation
• Even cacti probably benefit from irrigation for the first
year
• Wait for some time after planting- immediate water
stresses them
• Usually once a month is very adequate for cacti
• Often irrigation can stop after 1 year for native plants
though they may benefit during excessive heat
• More frequent intervals during the very hot, dry
months
• Less frequent/no irrigation during monsoon
weather
Watering Tips
• Signs of underwatering:
• Older leaves turn yellow or brown and drop
• Leaves are dull, wilted, or drooping
• Leaves curl
• Stems or branches die back
• Signs of overwatering:
• Leaves turn a lighter shade of green or yellow
• Young shoots are wilted
• Growth is excessive
• Algae and/or mushrooms are on or around plants
Fertilization in Arizona
• Native plants usually do not require fertilization
unless nutrient deficiencies occur
• Nitrogen and iron are the two nutrients most
commonly lacking in desert soils
• Secondary to lack of organic materials
• Alkaline soil limits availability of iron
• Phosphorus and potassium are plentiful in desert
soils
• Adding phosphorus at planting may increase blooming of
flowering plants
Need Help? Got Questions? Ask your
Master Gardener!!
•AYMG Programs
•Website:
https://sbmastergardeners.wordpress.com
•Plant call hotline:
Pat Flanagan
520-407-6459