By McKenna Rowles, Irrigation Manager
Let’s start by refuting a common landscaping myth: “It’s cool out, so I don’t need irrigation.” We hear this a lot. The reality is that plants still need consistent moisture—especially evergreens, new plantings, and seasonal color—even in cool weather, when wind and sun can dry out soil quickly. If irrigation is cut off entirely, root systems can dry out and stress plants heading into the winter months. That stress makes them more vulnerable to cold damage and less likely to bounce back in spring.
When we adjust irrigation schedules in the fall, the goal is to match water output to the plant’s needs. Think of irrigation in cooler months as “maintenance mode” rather than “growth mode.” You’re keeping the soil from drying out completely while avoiding excess water that can cause root rot.
Quick Tips for Cool-Weather Irrigation
Don’t shut it off completely – As summer winds down and temperatures drop, it’s tempting to think irrigation isn’t as important. While it’s true plants need less water in cooler weather, turning your system off completely can do more harm than good.- Adjust run times – Shorter days and cooler temperatures slow evaporation, meaning water lingers in the soil, saturating roots for longer periods. To account for this, water less often and for shorter periods of time. Slightly moist soil allows roots to establish and helps plants survive winter.
- Don’t neglect seasonal color – Fall annuals like pansies, violas, and snapdragons bring a pop of color to the landscape when everything else is slowing down. These plants establish best with steady moisture right after planting. Without this, they may struggle to root in before frost. Once established, they still benefit from occasional watering during dry spells, even in winter.
- Avoid overwatering – In fall and winter, excess moisture can actually be more damaging than drought. Because cooler temps mean soil holds moisture longer, this creates a prime environment for fungal pathogens and root rot, which can quietly weaken plants over the season. Additionally, soggy soil reduces oxygen availability in the root zone, stressing plants and making them more vulnerable to pests and disease. The key is balance: enough moisture to keep roots healthy, but not so much that they’re left sitting in waterlogged soil.
Don’t shut it off completely – As summer winds down and temperatures drop, it’s tempting to think irrigation isn’t as important. While it’s true plants need less water in cooler weather, turning your system off completely can do more harm than good.Cooler weather is the time to fine-tune irrigation, not forget about it. Our team can adjust irrigation schedules to give seasonal beds the extra water they need early on, then taper back as they mature. A well-set irrigation program helps save water, supports healthy root systems, and keeps landscapes looking their best through the dormant season. When spring arrives, plants that have been properly cared for will come back stronger, healthier, and ready to thrive. If you’re a Ruppert team member, talk with your branch about how you can help clients protect their landscapes this season. For our clients, reach out to your account manager to review your irrigation program and make sure your property is set up for success.