PPDL Picture of the Week

May 15, 2017

The Effects of Abundant Spring Rainfall on Nurseries and Landscapes

Kyle Daniel, Department of Horticulture and Landscape Architecture

The spring rains came as a mild drought was beginning to and did not let up for a couple of weeks (Fig. 1).  Many areas in Indiana experienced moderate flooding of creeks and rivers, causing minor damage.  Most of the news articles and publicity has focused on the effects on agronomic crops.  Though the nursery and landscape industries are not affected as the agronomic industries, the rainfall has affected the green industry as well.

Being the eternal optimist and starting out with the positive aspects, the nursery industry will begin the growing season with adequate water reserves in irrigation ponds and well water.  Even if a drought occurs this summer, there should be enough water reserves for irrigation.  Also, any planted material in the early spring received plenty of moisture.

On the not so positive side, field dug trees had to be postponed due to excessive soil moisture.  Many fields in the state have been too wet for supporting equipment during the heavy rainfall.  Another drawback to the rainfall is reduced oxygen exchange in flooded areas (Fig. 2) in pot-in-pot and field production systems.  Any preemergence herbicides applied in the nursery or landscape prior to the rainfall will have a reduction in duration due to leaching and/or runoff. 

There has been some research from the USDA studying the effects of flooded/anaerobic conditions leading to an increase in insect infestation on trees.  Be sure to monitor plants over the next couple of months to prevent substantial insect damage.  Also, irrigate as necessary if drier conditions settle into the region to prevent other additional abiotic stress.

 

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​Click image to enlarge​

 

Figure 1. Rainfall in April and May in Evansville, Indianapolis, and South Bend, Indiana.​


Figure 2. A flooded field in pot-in-pot production.