When it comes to beautiful, vibrant landscapes in Central Iowa and other USDA Zones 5a and 5b, the growing season is more than just spring cleanup and summer watering. To truly support optimal plant health and encourage reblooming in flowering plants, continued care throughout the entire season is essential, and it’s backed by science.
Why Ongoing Care Matters
Just like people need more than one good meal to stay healthy, plants require consistent, ongoing support to perform at their best. Proper pruning, fertilization, watering, and pest management throughout the growing season are key not only to vibrant blooms, but also to overall plant vigor and longevity.
Studies show that stress accumulation over a season, such as from inconsistent watering or unchecked pests, can significantly reduce flowering and root development in ornamental plants (Sanchez-Blanco et al., 2014). Even minor environmental stressors, when allowed to persist, decrease chlorophyll production and hinder photosynthesis, impacting the plant’s ability to store energy and rebloom later in the season.
Promoting Reblooming in Flowering Plants
Many popular flowering plants in Zones 5a and 5b, like daylilies, roses, coneflowers, and salvia, have the potential to rebloom or extend bloom periods but only if properly maintained.
Here’s what the science says:
- Deadheading (removing spent blooms) redirects the plant’s energy away from seed production and toward new flower development. A study published in HortScience found that deadheading increased rebloom rates in herbaceous perennials by up to 30% (Frey & Janick, 1991).
- Regular fertilization with a balanced or bloom-boosting fertilizer ensures that plants receive the right nutrients, especially phosphorus and potassium, to fuel extended flowering. Over-fertilizing with nitrogen, on the other hand, can lead to excessive leafy growth at the expense of blooms (Mills & Jones, 1996).
Best Practices for Mid-Season Plant Health
Whether you’re managing annuals, perennials, or woody ornamentals, these ongoing tasks will keep your landscape thriving all summer long:
1. Mulch Monitoring
Mulch conserves moisture and suppresses weeds, but it also breaks down over time. Refresh mulch layers mid-season (2 to 3 inches deep) to keep roots cool and reduce stress from summer heat spikes, especially in exposed beds.
2. Smart Watering
Use deep, infrequent watering to encourage deep root growth. Avoid frequent shallow watering, which leads to weak root systems and drought stress. Drip irrigation systems or soaker hoses are ideal for targeting water at the root zone while preventing fungal issues on foliage (Chalmers et al., 1981).
3. Fertilization Check-In
Mid-summer is a good time to reassess nutrient needs. Use a soil test to determine if supplemental feeding is needed. Many flowering shrubs and perennials benefit from a second dose of fertilizer in July to support late-season performance.
4. Pest and Disease Patrol
Keep an eye out for Japanese beetles, aphids, powdery mildew, and other seasonal pests. Early detection and integrated pest management (IPM) strategies can prevent the need for harsh chemical interventions later.
5. Pruning and Pinching
Many perennials, like mums and asters, benefit from pinching back in early summer to encourage bushier growth and more buds. Rejuvenation pruning of woody shrubs can also enhance airflow and reduce disease pressure, while encouraging new growth for the next season.
Zone 5a and 5b-Specific Tips
In USDA Zones 5a and 5b, we experience shorter growing seasons and more extreme winter-to-summer shifts than in warmer zones. That makes continued care even more critical for sustained plant health and bloom performance.
- Frost to heat transition: Be mindful of temperature swings in May and early June. Plants pushed too hard too soon may experience transplant shock or sunscald.
- Extended fall blooms: With the right care, many perennials and annuals can push blooms into early October, extending your garden’s beauty well past Labor Day.
Keep It Growing
Think of your landscape as a living investment. The more attention and maintenance you give it throughout the season, the greater the return—whether that’s in the form of dazzling blooms, lush greenery, or pollinator activity.
At RJ Lawn & Landscape, we’re here to help you keep your property thriving from spring thaw to fall frost. Our team is trained in seasonal plant care strategies that align with the latest horticultural research, ensuring your landscape stays strong, colorful, and resilient.
References:
- Frey, M., & Janick, J. (1991). The effect of deadheading on reblooming in herbaceous perennials. HortScience, 26(4), 425–428.
- Sanchez-Blanco, M. J., et al. (2014). Plant response to drought stress and climate change. Agricultural Water Management, 132, 40–49.
- Mills, H. A., & Jones Jr., J. B. (1996). Plant Analysis Handbook II. MicroMacro Publishing, Athens, GA.
- Chalmers, D. J., Mitchell, P. D., & van Heek, L. (1981). Control of peach tree growth and productivity by regulated water supply, tree density, and summer pruning. J. Amer. Soc. Hort. Sci., 106(3), 307–312.
