Fall is time to plant and enjoy the winter blooms. Below is a short list of my favorites. For a more complete list check out this website: University of Arizona.
Pansies: They come in blue, purple, orange, yellow, white, red, and pink. Pansies get 6-12″ tall, can be planted in sun to partial sun but will do better when the heat hits in partial sun, have average water needs, are edible, and are easy to grow. Pansies can be planted Oct. through Feb. in the Arizona low Desert and will bloom through April/May depending on weather.
Calendula or Marigold: They come in orange or yellow colors, can take full sun, easy to grow, get 15-18″ high so would be used as a focal point in the center of a bed or in the back, take minimal water, edible, make a good cut flower, attracts butterflies and reseeds. This plant can be planted Sep. through Nov. and will bloom Dec. through May in the Arizona low desert elevations.
Geranium: They come in red, purple, pink, orange, yellow, or white. Geraniums get 12-18″ tall, take partial sun, lots of water, and are easy to grow. They can be planted in the Arizona low desert from Sept. through April and will bloom into June.
Snapdragon: They come in purple, red, pink, yellow, and white. Snapdragon will grow 6-36″ tall. These are the long stalk type flowers you see in the center or back of arrangements. They do best in full sun, average water, easy to grow and make a good cut flower. Snapdragons can be planted Oct. through Feb. and will bloom from Nov. into May.
Sweet Alyssum: These come in white, blue, pink, or easter bonnet. They are low growing and make a very nice border flower. They do well in full sun to partial shade, take quite a bit of water, are easy to grow and have a nice fragrance. They can be planted Oct. through March and will bloom Oct. through May.
Petunia: They come in blue, purple, yellow, pink and white. Petunias grow 6-18″ tall, require a lot of water, are easy to grow, attract butterflies, and are fragrant. They can be planted Sept. through March and will bloom Oct., Nov., March, April, and part of May. They are frost sensitive and will die off with frost and need to be replanted. May survive light frost if covered.
For best results and an abundance of foliage and blooms use lots of mulch and a good pre-plant fertilizer like 16-20-0 ammonium phosphate. Water only enough to keep the soil slightly moist or slightly dry. Too much water causes fungi and will kill the plants just as quickly as not enough water. Also remember if the weather calls for a heavy frost or even a light one cover the flowers with a sheet all the way to the ground. This will help to ensure they stay alive and bloom all winter. I have had great success with all of these plants and have been able to keep the blooming and alive all winter with a little care and do not forget to cover them from frost.
Contact a local Landscape Designer