Flower Planting Guide for the Low Desert

There are many types of beautiful flowers that can be grown in the low desert. Use this chart to plan for year round color and interest in your yard. Select plants that will do well in our climate and meet your individual needs. Plants are listed in alphabetical order by their common name. Some plants with more than one common name are listed under each common name. The common name is followed by a letter designating whether the plant is annual (A), biennial (B), or perennial (P) here in the low desert, and then the botanical name for the plant.

Annuals

Annual flowers complete their life cycle — vegetative plant, bloom, setting seed, to death of the plant — in one growing season.
Most annuals need to be replanted each year, but others easily re-sow themselves. Their seed is scattered by wind, weather and wildlife, to pop up the next season when conditions are favorable. These unexpected visitors are called “volunteers” and can be a delight or a source of frustration, depending on your outlook and how rigidly you follow the garden’s original design! Larkspur, cornflower, poppies, desert marigold, calendula, scarlet flax, gaillardia and Johnny- jump-ups are a few flowers that are easy to grow and readily reseed.

Gardeners love annuals for their riotous colors.  They perform quickly, especially if transplants are used, and provide relatively long periods of bloom. Annuals are particularly useful to conceal bare spots while landscape plants become established; create masses of color as a focal point; or fill containers to establish a cheerful presence at entryways and enter- tainment areas, including patios and pool decks. At the end of the annual’s growing season, the entire plant is put in the compost pile and something else can take its place. Many gardeners find it fun to experiment with annuals. If you don’t like the color combinations you chose, plant something else next season.

Biennials

Biennials grow vegetatively in their first year, flower in the second year and typically die after flowering. Because we have two growing seasons here, some biennials complete their entire life cycle in one year.

Perennials

Perennial plants live more than two years and, once established, bloom each year. Some die back to the ground in their off-season; others retain foliage year around. In the low desert, perennial off-seasons are usually during the intense heat of summer and the colder winter months. You may notice that many plants that are considered perennials in other parts of the world are listed as annuals in the attached chart. That’s because they don’t receive enough winter coldness for dormancy or can’t survive our summer heat (without inordinate amounts of care) and are more successfully grown in the low desert as annuals.

Perennials require more maintenance than do annuals. They may need to be cut back during their off- season, and divided and replanted as they increase in size. Some of their blooms are tall or heavy enough to require staking. Typically, perennial flower beds are designed to have different combinations of flowers blooming as the year progresses. Unlike annuals, which have a lengthy flowering period, most perennials display peak blossoms for a two- or three-week period. Thus, the design of a perennial garden should take into account when the flowers bloom, as well as their color, height and leaf texture.

Time to Bloom

Next, the chart provides information on approximate time from planting seed untill the plant will bloom. You can use this to plan for blooms at a certain time of year. On a calendar identify the date you want blooms, back up the number of days listed in the “Time to First Bloom” column and plant seed slightly before to slightly after that date. Plant over a window of time to allow for variation due to weather conditions.

Height

The information on plant height will be useful in designing your garden. When planting a one-sided bed (next to a wall, for example), put taller plants in back. If the flower bed can be seen from two sides, tall growers look best in the center so they don’t conceal smaller plants.

Light

Most plants need a minimum of eight to ten hours of sunlight to produce flowers, however, there are a few that thrive in the shade. Identify how much light you can provide in your planting bed and select plants that will thrive in that environment.

Difficulty

This is an indicator of how hard it is to grow that plant in the low desert.

Water Needs

Group plants with the same water needs to avoid under- or over-watering individual plants.

Special Characteristics

Lures
Hummingbirds: Hummingbirds, which feed mostly on insects, are a wonderful addition to your garden. They are primarily attracted to red and orange tubular shaped flowers with lots of nectar but may be attracted to other vibrant colors. Plan for year round bloom.

Seed-eating Birds: Enjoy the antics of a variety of birds as they harvest seeds from your flowers. Many of the native wildflowers are great food sources for birds. To feed the birds, you must allow the flowers to go to seed and let the birds provide the color and beauty of the garden for a bit. Some people can not tolerate the “messy” look of seed stalks.

Butterflies: One of the best ways to ensure having butterflies in your garden is to nurture the caterpillars. Think of them as baby butterflies.
Learn to identify and enjoy them. Butterflies are attracted to wide, flat flowers on which they can easily land. Position plants in a sunny place,
sheltered from wind. Grow large clumps of flowers. Maintain diversity in height, color and blooming period.

Edible
Many flowers are edible. Though few are flavorful, they are beautiful and can be a fun or elegant edition to the meal.

Cut Flowers
Some flowers perform much better as cut flowers than others. They have longer stems, they hold their bloom longer, and work much better in arrangements.

Dried Flowers
Some flowers can be preserved as dried flowers much more easily than others.

Wildflowers
The term “Wildflowers” in this chart refers to native annuals and other plants which are easily grown from seed and can naturalize by reseeding.

Reseeds
Some annuals reseed themselves quite readily. You may either enjoy future generations or remove the spent blossoms before seeds mature and drop.

Fragrance
What some people find an “attractive fragrance ,” others find an “overpowering smell.” You may want to go to a nursery and personally take a whiff of the type of plants you are considering growing for fragrance before you cover your yard with them.

Color
Color is a powerful tool. Complementary colors, those on opposite sides of the color wheel (for example yellow & purple, orange & blue) can make pleasing contrasts. Colors next to each other on the color wheel are said to be harmonious (for example, yellow & orange or purple & blue). Green, blue, and purple are considered cool colors and can make the yard seem cooler and more inviting in the summer. Warm colors — red, orange and yellow — can add excitement to the landscape. Hot colors appear to be closer than cool colors so put cool colored flowers at the back of the garden to make it appear larger. Experiment with other color combinations.

Planting and Flowering Guide

Remember that the low desert provides gardeners with two distinct growing seasons. Warm season flowers can be planted from approximately February through May, for bloom through the summer. Cool season flowers are planted in the fall and bloom through May, or until temperatures heat up. This Guide provides a range of dates that offer a high probability of success. However, yearly weather conditions can vary considerably and the low desert contains a myriad of microclimates. Use these dates as general guides and adjust them as necessary for your local conditions.

Soil

Most flowers prefer a nutrient-rich, well-drained soil (nobody likes wet feet). If this is your first attempt or if your patch of hard rock fills you with despair, you might want to concentrate on the flowers marked as “Wildflowers” or “Reseeds” in this Guide. Many of these don’t require as rich a soil, preferring a more “native” environment.

Fertilizing

Flowers, like vegetables, are heavy “eaters” and will require nitrogen for vegetative growth and phosphorous for healthy roots and reproduction, which includes flowers. However, too much nitrogen may create a healthy, vigorous plant, with few flowers. Phosphorous is not water soluble and thus can not move easily through the soil. It needs to be placed deep enough in the soil where the plant’s roots can easily take it up. Thus, it should be mixed into the soil in the root zone before planting, or dug into side trenches if required after the plant is established. If plants are in the ground, fertilizer is best applied to moist soil to help prevent burning.

Because there are so many variables involved — the condition of the soil, plant species, fertilizer type (dry, slow release, liquid), weather, your garden’s microclimate — there is no magic formula for applying fertilizer. Follow the directions on the label of the fertilizer you choose. Depending on your conditions, you may need to add fertilizer as often as every six weeks or so during the flowers’ peak growing season. If you have nutrient-rich soil that is well prepared before planting, additional fertilizer may not be required. Consider keeping a garden journal, noting what kind of fertilizer you used, how much and when it was applied. Keep an eye on your plants. Do they look green and healthy? Do buds and flowers form? Let your plants and your “eye” determine what is needed.

Flowers grown in containers need a regular schedule of fertilizer or a timed-release fertilizer mixed in at planting time. Some Master Gardeners recommend applying a diluted fertilizer with each watering in cooler weather. In hot weather, you may need to water daily, so cut back on fertilizer to once a week. This is only a guide. The size of the container and the plants will determine fertilizer needs.

Tips

Perennial flowers show to their best advantage when planted in groups of odd numbers (three, five, seven) in a drifting effect. Annuals look great when massed together for maximum color effect, although they can also work well when grouped in odd numbers. Single plants of many varieties tend to look disorganized. Avoid straight rows for a more natural appearance. Take a look at how plants grow in nature — when’s the last time you saw a straight line? However, smaller, low growing plants can work well as a continuous border along the front of a bed with taller flowers behind in two or three “layers.”

“Deadheading” is the term used for removing spent blossoms. Cutting or pinching off the dead flowers on a weekly basis prolongs the blooming period because the plant doesn’t expend its energy on seed production. Toss the dead flowers into your compost pile.

White flowers show well at dusk. Use them near patios, entryways and entertainment areas where they can be shown to best advantage.

SOURCE:
http://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1100.pdf