Summer Gardening To-Do List
Summer 2026 is shaping up to be hot and dry. Here’s how to help your garden beat the heat.
Water so it counts – We’ve had a lot of panicked calls at the Extension office this year about “only” watering the lawn two days a week. Measuring water in days makes as much sense as measuring milk in minutes—neither is a unit for liquid volume. The first step to knowing if you’re watering your plants efficiently is to know how much water you’re actually giving them. I once maintained a garden of waterwise plants; we watered with high efficiency “stream rotors”. The irrigation was set to run for 15 minutes every three days. You might think that watering two or three times a week is ideal, but knowing the frequency per week by itself doesn’t tell you how much you’re watering. The irrigation heads’ precipitation rate is required information; and for high efficiency heads it can be quite low. In this case, it was a half-inch per hour, which meant that the garden was being supplied with an eighth of an inch of water every three days—just enough to promote fungal pathogens and evaporate, but not enough to actually penetrate the soil even a tiny bit. Our high-efficiency watering was actually 100% water waste.
Depending on your soil texture, soaking the root zone could take an inch or more of water. To figure out how long it takes to apply an inch, you can do some arithmetic from your water bill (an inch of water is around 2/3 of a gallon per square foot), or you could put a rain gauge on the lawn while the sprinklers run. If you’re really feeling fancy, you can look up the precipitation rate of your irrigation heads online (you’ll need the brand, model, and your home’s water pressure). Be sure to check your irrigation system for leaks, poorly adjusted heads, or other maintenance issues regularly. Since many systems run at night, make checks part of the regular routine, rather than waiting for problems to manifest as dead plants, high water bills, or—adding insult to injury–both.
Cut back spring-flowering perennials – July is often when the garden is suddenly more about leaves than about flowers. Perennials that flowered in May and June can begin to look tired or start to flop over (“lodging”). Cut them back to promote new growth that keeps the garden tidy and fresh. Late-summer and fall-blooming perennials can be cut back or pinched by up to half to promote more flowering and an extended flowering season, but be sure to finish before mid July or you could pinch yourself out of a flower display.
Prevent blossom-end rot on your tomatoes, peppers, and squash – Blossom-end rot is a localized calcium deficiency in growing plant tissues (like your developing fruits) but it is not caused by a shortage of calcium in the soil. Rather, uneven watering causes temporary calcium shortages in growing fruits when the plant runs out of the water needed to remove minerals. Adjust your irrigation schedule to make sure that your larger plants in hotter weather are getting enough moisture to provide you with a harvest. Nutrition is still required, though! All annuals, including vegetables, will appreciate an application of balanced fertilizer.
Prepare to plant fall vegetable crops in late July or early August – It might seem early to be thinking about fall, but now is the time to plan for your late season crops of lettuce, beets, radishes, and other cool-season crops. In order to mature before our typical early October freezing temperatures, they’ll need to be planted soon, no later than mid-August. Consider providing them shade to help them stand the heat!
Don’t forget IPM – Integrated Pest Management (IPM) is an important part of long-term gardening success. Make sure you spend time in your garden looking for early signs of pests and diseases. Common summer problems include powdery mildew, squash bugs, and Japanese beetles.
Japanese Beetle Plant Damage Lists
The plants on this list are based on observations submitted by members of the gardening public during the 2021 growing season. Some plants may be listed under more than one damage level; this is intentional, since beetle feeding can be influenced by surrounding plants and environmental factors. Want to report observations? Click here. You’ll need the botanic name of your plants and about one minute!
Growing Flowering Meadows From Seed
Learn how CSU Extension is working to bring high-impact, low-input landscapes to a neighborhood near you!
