Climate is the key to landscape gardening in the Southwest. Our climate
ranges from subalpine to sub-tropical deserts, so a wide array of landscape
trees and shrubs can be grown in Southwest. Very few landscape trees and
shrubs grow well over the entire range of climates found in the region.
Therefore, it is important to know how local climate influences the types of
plants that can grow in the region. Many climatic factors play a role in
determining the kinds of plants that will grow in a given location. Some of these
factors include geography, minimum winter temperature and maximum
summer temperatures, rainfall amount and distribution, humidity, day length
and light intensity. The Sunset climate system divides the Western United
States into climate zones and then lists many landscape plants and what
zones they grow best in. Before viewing the topic videos, review the website
and readings, and answer the following questions about climate. View the
PowerPoint presentation on six important terms discussed in this topic.
Climate Zones:
1. What factors are used to determine the Sunset Climate Zones?
Amount of winter days, how temperatures get
2. What is a microclimate?
3. What climate zone is Phoenix in and how does this affect the trees and
shrubs that grow the best in this area?
Subtropical desert, zone 13, gardening yr begins in fall for most vegetables
and annual flowers, fall planted crops grow slowly in winter and speed in mid
Feb and race throught the increasing temps of March and Aprul, Spring winds
can set back plants but summer storms cool down gardens shiled plants from
the sun and supply a little extra water
4. How does the climate in the Phoenix area differ from the other desert
climate zones in the southwest including climate in cities such as Tucson,
Las Vegas and Albuquerque?
Tucson- az int desert (12), biggest difference= winter cold, but harder
frosts spread over a longer cold season (zone 12- 8 months btwn freezes
and months between killing frosts, zone 13- averages more than 11
months between killing frosts)
Vegas- zone 11, cold winters , if soil moisture is inadequate, the
Study Guide for Topic: Landscape Trees and Shrubs for the Southwest
characteristic winds and bright sunlight may combine to dry out normally
hardy evergreen plants, killing them
Albuquerque- zone 10, definite winter season, favors deciduous fruits, cold
winter means spring planting growing seasons are long,
In order to understand this topic and your creative assignment for this module,
you will need to review some information about scientific classification.
Read the University of Florida information about scientific classification and be
able to answer the following questions.
Scientific Plant Names:
5. What is the first and second word in a plant’s botanical names called?
Scientific name- genus and species
6. What part of the scientific name is capitalized?
First letter of the first word
7. What does the word cultivar mean? Is the cultivar name usually written in
Latin or English?
Plant varietythat has been produced in cultivation by selectivebreeding
Finally, review the following sections of the textbook and answer the
following questions before viewing the topic videos.
Landscape Trees and Shrubs:
8. Be able to define the following terms by viewing the PowerPoint
presentation
obroad-leaf- trees or shrubs with wide leaves, angiosperms
onarrow-leaf- narrow, needle like leaves, conifers
oevergreen- maintain a full canope of leaves throught the year,
remains green and fuctional through more than one growing
season
odeciduous- lose their leaves annually usually at the same time,
process of leaf loss by deciduous plants often accompanied by
dramatic change in leaf color
ocanopy – layer of leaves, twigs and small braches of trees and
shrubs that c0over he gouns when viewed from above, canopy
provide shade and cool landscape
oaccent- visually apparent; striking foliage, flower, or branch
colors, interesting textures or unique forms
You are now ready to watch the videos Landscape Trees and Landscape
Shrubs. Click on the video link in the Folder on the course website. At the end
of the videos, you should be able to answer the following questions based on
information in the videos, the presentations and your textbook readings.
9. What are the differences between shrubs and trees?
Shrubs don’t have a trunk, doesn’t grow off the ground
10. What is a shade tree?
Mesquite tree, palo verde
11. Which landscape shrubs are frost or freeze sensitive?
Indian rosewoods, bougainville, lantana
12. What pruning practice is best to maintain a natural and attractive shrub
form? \
Thinning cuts- texas ranger shrub, never shear
13. What are the ranges of flower colors for each landscape shrub?
Texas ranger- Magenta-lavender, bouganville- white, pink, magenta,
orange purple
Lantanta- whote, orange, pink red purple, oleander- white to red
14. Which trees and shrubs attract wildlife?
Red yucca
15. Which landscape trees produce edible fruits for people and wildlife?
Mesquite trees- edible pods, olive trees, rosewood trees- pods
16. Which landscape shrubs or trees cause respiratory allergies in many
people?
Olive trees
17. What characteristics of form and accent define each of the landscape trees
reviewed in the video?
Amount of shade, space needed to grow, pruning care, aesthetic
18. Which landscape trees are evergreen? Which are deciduous?
Chinese elm- deciduous
Lantana,oleander- evergreen
Landscape trees and shrubs mentioned in these videos are listed below. If you
want more information about these plants, look them up in your textbook, The
New Sunset Western Garden Book Plant Encyclopedia section and visit
Dr. Chris Martin’s: Virtual Library of Phoenix Landscape Plants .
(Plants are listed by their genus and species).
Landscape Trees
Dalbergia sissoo (Indian rosewood)
Olea europaea (olive)
Parkinsonia florida (blue palo verde)
Prosopis sp. (mesquite)
Ulmus parvifolia (Chinese elm)
Landscape Shrubs
Bougainvillea sp. (bougainvillea)
Hesperaloe parviflora (red yucca)
Lantana sp. (lantana)
