Garden Update: Heavy Rainfall, Strong Winds, High Humidity

Kathleen Cue, Nebraska Extension Horticulture Educator in Dodge County (Week of August 9, 2021)

Nothing deepens the appreciation for rainfall like a gentle rain and a light wind. But this is the Midwest, lest we forget, and weather conditions rarely follow our druthers. Take, for instance, the most recent rainfall and wind event. The tomato cages, with plants weighted by many tomatoes, bent to the ground in our Growing Together Nebraska garden. Luckily, the heavy winds didn’t rip up roots, but the tomato plants’ fall caused damage to the nearby pepper plants, necessitating early harvest of some of the peppers.

Vegetable Plants
Ponding water prevents oxygen reaching plant roots, where anaerobic conditions promote root and crown rot, leading to rapid plant decline.  Incorporating lots of organic matter into a clay soil will increase water infiltration, making ponding less of a problem. Water droplets splashing from the soil to the undersides of plant leaves inoculates them with pathogens like anthracnose and Septoria leaf spot on tomatoes. Mulching with shredded newspapers around vegetable plants lowers the possibility of pathogen-carrying droplets splashing onto leaves.  As water evaporates from plants and soil, humidity is increased, furthering the likelihood of fungal pathogens gaining a foothold. Plants susceptible to fungal diseases can be preventatively sprayed with a fungicide but once fungal diseases are ensconced in leaves, fungicides provide little to no curative effects.

Trees and Shrubs
The ideal time to trim trees and shrubs is April through June.  Nature’s inopportune storms are oblivious to this timeline and this will entail pruning outside the ideal time. Removing dangling branches, known as “hangers”, as well as making clean cuts to jagged stems are important for several reasons—human safety and tree health being foremost. Wound treatments are not recommended as they hasten tree decay. Fertilizing to “help” trees and shrubs following a stressful event favors many fungal and bacterial infections and is not advised.

Rust is a fungal disease of turfgrass, becoming noticeable when a walk through the lawn results in rusty colored shoes.  Close mowing, night watering, a thick layer of thatch and low soil fertility contribute to rust development. Again, fungicides will provide little in the way of curative effects, so correcting poor management practices provides the best chance to stop the disease from developing further.

Since fungicide applications are limited in providing curative benefits, clean-up of fallen and broken plant debris, as well as removal of disease-damaged leaves are the best options to limit disease spread. Increasing air circulation, keeping irrigation water close to the ground, and mulching so soils retain their moisture are all important practices for good plant health.

tomato cages