From the garden
For West Texas gardeners the Fourth of July is the day we celebrate our nation’s Independence Day, but for gardeners July 4 is also the target date for deadheading and rejuvenating flowering perennials.
Deadheading in early July gives plants sufficient numbers of weeks needed to rebloom before autumn. Deadheading, the action of cutting back spent flowers to promote future flowering is often called the “Chelsea Chop,” giving homage to the Chelsea Flower Show in England (a must-do bucket-list-item for gardeners who have never attended). In England the cutting back of perennials is done around the time of the show in late May but for us July is our target.
Deadheading is the removal of flower heads as they senesce, begin to fade and eventually die.
Deadheading technique for annuals and perennials: • Snip off senescing flower heads before seeds set.
• Cut flower stalks back to the nodes from which the flowers formed, keeping as many leaves as possible.
• If flower heads did set seed on an annual, consider saving the seeds for next year’s crop.
• Most flowering plants benefit from deadheading, but a few are asters, columbine, chrysanthemum, dahlia, daisy, Echinacea, marigold, petunia, phlox, Rudbeckia, sage, scabiosa, verbena and zinnia.
Rejuvenating technique for perennials:
• Prune all spring-blooming shrubs by mid-July because the plant hormones that determine if buds will be foliar or blooms are active in late summer. Shrubs like quince, forsythia, lilacs (Syringa), spirea, viburnum bloom on previous season’s wood.
• Regenerates and prolongs the flowering period. Flowers are tremendous carbohydrate users, especially when they begin to set seed at the end of the flowering cycle. At the end of the bloom cycle the carbohydrates produced during photosynthesis are channeled to the developing seeds at the expense of producing new blooms. Removing senescing flowers allows carbohydrates to now be directed to the development of new blooms.
• Controls the shape of flowering plants that can otherwise become leggy and flop over. Deadheading results in shorter, more compact plants. To deadhead fall-blooming plants like chrysanthemums simply pinch out the growing points of all stems to encourage lateral buds to develop. If the size of these plants is not reduced, flowers will form in September and October on the terminal points of long, thin stems, rather than on the ends of bushy compact, attractive plants.
Happy July 4th to all our readers!
Ellen Peffley Harp, a retired professor of horticulture at Texas Tech University, writes about gardening for several Texas newspapers.
