Four O’Clocks (Mirabilis jalapa) are garden plants known for their vibrant, trumpet-shaped flowers and evening fragrance. These blooms typically open in the late afternoon. Strategic cutting back helps manage their growth and encourages a more prolific display of flowers, keeping them healthy and looking their best.
Purpose and Timing for Cutting Back Four O’Clocks
Cutting back Four O’Clocks serves several purposes for plant health and appearance. Pruning helps manage the plant’s size, promoting a bushier growth habit rather than leggy stems. It also encourages more abundant flowering by redirecting the plant’s energy. Removing dead or diseased foliage maintains plant vigor and prevents the spread of issues.
The timing for cutting back Four O’Clocks varies by desired outcome. Throughout the growing season, deadhead spent flowers to encourage continuous blooming, as each flower typically lasts only one day. Removing spent blooms is a beneficial practice. Light trimming can be performed mid-season to maintain shape, reduce legginess, or promote bushiness.
For dormancy preparation, especially in colder climates where tuberous roots are overwintered, a hard cutback in late fall or early winter is appropriate. In warmer climates where they are perennial, a significant cutback rejuvenates overgrown plants. Early spring is also suitable for pruning, allowing removal of winter-damaged growth before new growth emerges.
Methods for Cutting Back Four O’Clocks
Proper tools ensure effective, clean cuts when pruning Four O’Clocks. Use clean, sharp pruning shears or scissors to prevent disease and ensure precise cuts. Disinfecting tools with a solution of one part bleach to nine parts water before and after use helps maintain plant health.
For deadheading, simply pinch or snip off spent flowers just below the bloom or above a leaf node. This prevents the plant from expending energy on seed formation and redirects it towards producing more flowers. For light trimming and shaping, cut stems to a desired length or to promote new growth. Always make cuts about 1/4 inch above a leaf node or branching point, at a 45-degree angle, to encourage healing and new growth. Pinching back the main shoot of young Four O’Clock plants promotes a bushier habit and more flowering.
When performing a hard cutback for dormancy or rejuvenation, cut stems significantly, often to a few inches above the ground. This prepares the plant for winter and revitalizes overgrown plants in perennial zones. Promptly remove any yellowed, brown, or diseased leaves and stems by cutting back to healthy tissue. This practice improves air circulation and reduces the risk of fungal diseases.
Aftercare for Four O’Clocks
After cutting back Four O’Clocks, appropriate aftercare supports plant recovery and new growth. Immediately after pruning, water thoroughly to promote healing and reduce plant stress. Adequate hydration benefits recovery and new shoot emergence. Avoid overwatering, as soggy soil can lead to root rot.
Fertilization is generally not needed immediately after a hard cutback, but a light feeding can encourage new growth after lighter trimming. Monitor the plant closely for signs of new growth, stress, pests, or disease in the weeks following pruning. Regularly inspecting the plant helps address any issues promptly.
Cleaning up all pruned material from around the plant’s base is good practice. This prevents debris accumulation that could harbor pests or diseases. If a hard cutback was performed for winter dormancy, especially in colder climates, lift the tuberous roots before the first freeze and store them in a cool, dry, frost-free location until spring.