Ample rainfall and cooler-than-normal temperatures have been great combinations for healthy plants in well-drained locations. For plants that already were struggling from previous years’ stresses or that are sitting in repeatedly saturated areas, however, the excess moisture may prove detrimental. How to help struggling garden plants depends on each situation and may change with what happens later in the season, although improving drainage is key in most situations.

The best ways to improve soil drainage are to amend the soil with compost or organic matter, elevate the soil surface by building a raised bed or berm, and/or install underground drains. Each of these options may sound daunting, but so does replacing plants after a year like this one. The easiest option, adding compost, is good for the soil in any weather conditions.

Sand is one of the worst things that can be added to poor soil. Yes, sand drains better than clay on its own, but when the two are mixed, they create concrete. Unless you are building a golf course with engineered soils, stay away from sand in the yard or garden.

Beyond increasing drainage, certain symptoms on plants may offer clues as to what is going on in individual situations.

Problem 1: Yellow or pale green plants. Recently transplanted veggies and annual flowers, pin oaks, river birches and white pines are most commonly affected. Most likely, the saturated state of the soil is inhibiting iron uptake by the plant, leading to a condition known as iron chlorosis. This problem will probably go away on its own in drier weather, especially if it has not been an issue in previous years. If yellowing is a repeated problem in an area, consider amending the soil to improve drainage or testing and correcting high soil pH (another cause of iron chlorosis).

Problem 2: Edges of leaves turn brown. This symptom could indicate many different problems, but in repeatedly saturated soils it is most likely an indicator of root or stem rot. Excess water fills the air space in the soil around the plant and literally suffocates the roots. The stress weakens the plants to certain fungi and bacteria that live in the soil. Those fungi and bacteria invade root and stem tissues and kill them. Little can be done to help already-infected plants, but removing them quickly can help reduce the buildup of disease in the soil. Improve drainage if the area if possible.

Problem 3: Stunted plants. Stunting is most obvious in recently transplanted vegetables and flowers — like the tomato plants that have been the same height for the past three weeks. This may be a response to both the waterlogged soil and to the soil temperatures. Plants should recover in drier, warmer weather.

Problem 4: Weeds. Yes, weeds are an everyday occurrence in many gardens, but a few love saturated soil. Yellow nutsedge is at the top of the list for wet yards and gardens in this area. Once again, improving drainage is the best bet unless you want to dig them, pull them, spray them, or cover them with plastic every time a new crop pops up (which is almost as often as the rain).

Also, keep in mind that if the rain does quit falling this summer, even healthy plants may show more stress than usual because they have not developed adequate root systems. Deep, infrequent watering over the dry period will help to keep plants as lush and happy as some are now.

— Jennifer Smith is a former horticulture extension agent for K-State Research and Extension and horticulturist for Lawrence Parks and Recreation. She is the host of “The Garden Show” and has been a gardener since childhood. Send your gardening questions and feedback to features@ljworld.com.