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Garden flowers for the “dog days” of August

Published June 9, 2017

URBANA, Ill. – Every summer, gardeners notice that certain plants are beautiful up until the heat arrives. Then they fade and wither, leaving us with only the memories of what once was. To keep these plants looking good, watering becomes a nightmare during high heat and periods of no rainfall. Xeriscaping, or low-water-usage gardening, may be the answer. 

"The term xeriscape often brings visions of parched desert landscapes,” explains Martha Smith, horticulture educator with University of Illinois Extension. "A xeriscape can be colorful, attractive, and inviting while requiring far less water than traditional landscapes." 

By following a few basic tips, gardeners can use less water and still enjoy a colorful garden.

  1. Group plants according to water needs. Plant thirsty plants together to concentrate watering in specific areas, rather than “blanket” watering.
  2. Build soil lips or soil basins around plants to direct water to plant roots. Depending on plant size, this basin should be 3 to 18 inches from the base of the plant.
  3. Mulch gardens to retain soil moisture. 
  4. Keep beds weed-free. Weeds take up water that could be used by desirable plant material.
  5. If your soil drains too quickly, amend it by adding moisture-holding organic matter.
  6. Pick the right plant for the right spot. Choose plants that thrive in hot, dry conditions.

Here are some popular blooming “dog day” plants: 

  • Celosia, or cockscomb (Celosia argentea), is unique for its unusual feathery or brain-like flowers of bright red, yellow, orange, and pink. Celosia is an annual that may grow from 6 inches to 4 feet tall, depending on the variety. Bring fresh cut celosia inside for an excellent cut flower, or hang it to dry.
  • Spider flower (Cleome hassleriana) can reach 4 to 5 feet tall in full sun. The unique spider-like flowers are rose, violet, or white. Cleome is an annual, meaning it grows from seed every year. It will re-seed freely in your garden.
  • Gomphrena, or globe amaranth (Gomphrena globosa), blooms in a variety of bright colors including purple, orange, red, rose, and pink. Generally the plant grows 1 to 2 feet tall. This is an old-fashioned flower that is easy to grow. It makes an excellent dried flower that holds its color well. Pick just as the flowers open fully and hang upside down to dry.
  • Madagascar periwinkle, also known as annual vinca (Catharanthus roseus) is a plant that seems to thrive in hot areas. Its lush, dark green foliage is somewhat glossy and forms a 2-foot tall mound. Annual vinca is available in white, pink, purple, and bicolors. If you have a difficult southern exposure to work with, try this annual. It is slow to start if spring temperatures are cool and it does not tolerate wet areas.
  • Threadleaf coreopsis (Coreopsis verticillata) is a perennial that will reach 18 to 24 inches in height. It has yellow, daisy-like flowers that last from late spring to late summer. This plant will grow best if planted in a dry, full-sun area.
  • Orange coneflower (Rubdeckia fulgida) is the perennial form of blackeyed Susan. Its cheery yellow or orange daisy flowers brighten up the August garden. 
  • Blanket flower (Gaillardia species) is a perennial plant available in a variety of hot colors like golden yellow and mahogany red. Cultivars are available in a range of sizes with most growing in the 2-foot height range. Blanket flower tolerates dry soil and temperatures of 90 degrees Fahrenheit or higher.

“All of these plants will survive the hot days of August with very little attention and care, requiring only an occasional pruning off of old blossoms,” Smith says. “Try one or two next year and enjoy your garden all season long.”
 

News Source:

Martha Smith, 309-756-9978

News Writer:

University of Illinois Extension