Deadheading and Dividing: Essential August Tasks for Perennial Gardens
August is a crucial month for perennials! It occurs at the shift of seasons, as summer evolves into autumn. Perennial plants begin conserving energy to prepare for the winter ahead. Use deadheading and dividing to extend their bloom period and rejuvenate old clumps.
Contents
Perennials need your help to look their best! Precise deadheading and occasional division will ensure they stay healthy for years to come. Both tasks are crucial in the late summer garden to prepare your perennials for fall.
Deadheading is an annual task, and dividing occurs every two to five years, depending on the perennial. You’ll use deadheading to remove spent blooms and encourage new ones. Dividing, however, is useful for propagating your perennials and rejuvenating old clumps.
Now is the perfect month to pay attention to your perennials and prepare them for the upcoming winter season. Grab some pruners and a shovel, and get ready for these August perennial tasks!
How Perennials Behave in August
Perennial plants start to feel the cold in August. Though your garden may still have hot days, cool night temperatures grow more common this month. Shortening days act as a signal to plants, telling them it’s essential to sprout roots instead of flowers and fruits.
You’ll notice perennials turning yellow as they draw nutrients from their leaves down to their roots. Fewer flowers will bloom, though you can extend the flowering period with continual deadheading.
Some perennial species have a last hurrah at summer’s end. They flower prolifically before the first frost, offering one last explosion of color to celebrate the season’s end.
Deadhead for More Blooms
Deadheading isn’t just an August perennial task. It’s an essential technique year-round for boosting the flower power in your perennial garden. It coaxes more flowers from your plants, encouraging them to bloom more blossoms than they would in the wild.
What is Deadheading?
Deadheading is a task that removes old flowers to make room for new ones. Though it seems like a simple process, it causes a complex reaction from your perennials.
Plants grow to reproduce, and they use their flowers to form fruits and seeds. When you snip off the blooms, you cause your perennial plants to think that they haven’t reproduced. They’ll panic and grow more flowers as a response! Plants want to grow seeds, and you can use this against them to encourage additional flowers.
Deadheading works up until the first frost, when most herbaceous perennials begin to die back. Some cold-tolerant specimens, like pansies, may continue flowering after the first frost! Unlike dividing, you may deadhead perennials and annuals for the same effect.
The only downside of this August perennial task is that it prevents seeds from forming. If you want to propagate your perennials with seeds, you’ll want to stop deadheading them at the end of the season to allow seeds to form.
How to Deadhead
It’s simple! Using pruners or herbal snips, cut off each spent flower after it blooms. Be careful not to squish any bees or pollinators, and protect your hands when snipping thorny specimens like roses and barberries.
When completing this August perennial task, it’s best to remove the flowers right above a growth node so new growth can sprout healthily. Growth nodes occur where leaves sprout from the perennial stems. You’ll notice new shoots sprouting from the growth node after you snip off the spent flowers.
Some flowering plants have thin stems that are easily pinchable! Use your fingers to snip the spent blossoms off these thin stems. Petunias, pansies, and violas are pinchable.
Perennials to Deadhead
Many perennials in the garden benefit from deadheading! These are a few of the many plants that appreciate it in August:
- Chrysanthemum
- Coneflower
- Dahlia
- Hydrangea
- Petunia
- Rose
- Zinnia
Some species, like lilacs, bloom once or twice a year. Deadheading them won’t cause more flowers this year, but it will encourage more, bigger blooms next year.
In general, deadheading prevents plants from forming seeds, which allows them to redirect energy towards flower, root, and shoot production. Use it if you’d like to see more blossoms, and don’t use it if you’d like to save seeds.
Divide to Rejuvenate and Propagate
Dividing is a little different than deadheading. This task is best for spring or fall, and August is a perfect time to start the process if it’s mild out.
You’ll dig up a clump, separate it into multiple divisions, and plant the divisions throughout your perennial garden. Division does not work well for annuals. It’s ideal for perennials and thicket-forming shrubs.
What is Division?
Division is an essential propagation and rejuvenation task for your perennials in August. A healthy perennial tends to grow thick over time and crowd itself out. You’ll notice weak, leggy growth that’s less dense than it was in previous years. Dividing rejuvenates the clump to grow vigorously again.
Though dividing seems harsh, it will benefit your perennial garden in the long run. Replanting the divisions will multiply your plant supply. You’ll turn a single specimen into two or more new ones! Each piece of the clump will flourish in its new location.
Digging and dividing a perennial clump is difficult for the plant to adapt to. It’s best to do it in the fall or spring when temperatures are cool and the weather is mild. Consistent moisture and cool temperatures are crucial for a successful division.
How to Divide
Dividing can be different depending on the size of the perennial in question. You may dig up small clumps with a hand trowel and use a sharp knife to divvy them up into multiple pieces. This works well for potted plants from nurseries and garden centers.
Larger perennials in the ground require more work to divide. Start by digging up the clump in question. Set the shovel down a few inches away from the stems to ensure you dig up plenty of the roots. Make a circle around the perennial’s perimeter, then dig underneath the clump.
Using your shovel, lift the perennial up and out of its hole. Inspect it, and decide how many portions you want to create. Large plants may divide into five or more new ones! Stab your shovel down into the plant to divide it.
The goal of this August perennial task is to have many robust pieces of the clump, and each piece should have ample roots and stems. The more roots and shoots each division has, the more likely it is to grow successfully after replanting. Plant each one in a new hole, and water the site well to help them establish in the perennial garden.
Perennials to Divide
Many plant species benefit from dividing. It’s best to divvy up mature, robust perennials that have been growing for two or three years. It can be fatal for young plants that haven’t had enough time to flourish in the garden.
These are some of the many perennial species you can divide in August:
- Astilbe
- Bleeding Heart
- Checker Mallow
- Columbine
- Daylily
- Goldenrod
- Iris
- Peony
- Yarrow
The only perennials you don’t want to divide in the fall are those that bloom in August. It’s better to separate them in spring to avoid affecting their bloom period.
Key Takeaways
Deadheading and dividing are essential perennial tasks for August. Deadheading prolongs the bloom period, encourages bigger flowers, and prevents seeds from forming. Dividing is a propagation method that rejuvenates old perennials. No matter which you decide to do, this month is a good time for either task.
