Pruning Speedwell is only necessary for two reasons: 1) deadheading the spent flowers will help the plant produce blooms for a longer period in the summer, and 2) cutting the dead foliage and stems back in the fall cleans up the plant to prepare it for winter dormancy. Speedwell is an herbaceous perennial that will die back completely to the ground each fall. All of the flowering occurs on new growth that emerges in the spring.
The spent foliage can be removed from speedwell plants in the fall, and plants can be mulched with organic material to insulate the crown from cold and snow. Warmer-growing zones may notice that Speedwell behaves more like a semi-evergreen perennial, and all of the late fall growth doesn't die back until late in the winter or early fall. This growth will also help to insulate the crown and provide seed for non-migrating birds
Deadheading is pruning that should happen all through the blooming period of Speedwell. Cut the spent flower stems down to the next bud on the stem. This will encourage those buds to grow and develop into flower spikes. Feel free to cut back damaged foliage and stems at any time to keep the plant tidy and at less risk for diseases.
Why Prune Speedwell
Speedwell benefits from deadhead pruning and removal of spent foliage. Otherwise, herbaceous perennials require minimal pruning during the growing season.
How to Prune Speedwell
Step 1 - Deadheading
Cut back spent flower spikes all of the way to the first or second set of buds near the leaves. Try not to leave naked bloom stems, which spend more of the plant’s energy.
Step 2 - Fall cut-back for clean up
Gardeners in the colder growing zones should cut the top growth down to 2 inches above the soil as Speedwell begins to die back in the fall. Mulching around the plant, including the crown, helps to insulate the roots from winter cold and snow.
Step 3 - Early spring trimming
Gardeners in the warmer zones can leave the top growth alone until the early spring. The top growth protects the crown against heavy rains in the winter.
Speedwell Pruning Tips
- Regular deadheading allows the plant to produce more flower spikes
- Fall clean-up or spring clean-up depends on what hardiness zone you garden in
- Cutting back damaged stems or foliage during the growing season will not affect blooming or future regrowth.