This document printed from the University
of Illinois Extension Ag Update at http://www.extension.uiuc.edu/hww/
This Week in Agriculture
November 23, 2009
Dennis Epplin
Extension Educator, Crop Systems, Mt. Vernon Center and Interim County Director, Hamilton/Wayne/White Unit
Mt. Vernon Center 4112 N Water Tower Place
Mt. Vernon, IL 62864
Phone: 618-242-9310
FAX: 618-242-9433 depplin@illinois.edu
Winter Mulch Protects Strawberries
Depending on variety, strawberries have varying tolerance to cold. Lack of acclimation or "hardening" in the fall, as well as wide temperature swings, can decrease cold tolerance and increase winter injury to crowns. Research has shown that temperatures in the low teens can kill a high percentage of uncovered or poorly hardened plants.
"Mulching helps to insulate plants from low temperatures and quick changes," says Tony Bratsch, University of Illinois Extension horticulture educator. "Mulching also protects plants from drying winter winds which desiccate, or dry out the plants, especially when soil moisture becomes low or less available in frozen soils."
Strawberries are also shallow and somewhat brittle-rooted. Alternate freezing and thawing (frost heaving) of the soil in winter and early spring can damage roots. A layer of straw on the surface moderates this soil movement.
Bratsch says that strawberries grow and develop late into the fall months and should not be covered too early. They respond to low temperatures and moderate frost by gradually becoming more hardy and tolerant of cold. Signs of this tolerance include a "flattened" appearance, lack of any new leaves and red coloration of older leaves.
Apply mulch after plants have had time to acclimate and develop hardiness. Based on various studies, data indicates when soil temperatures at a 4-inch depth have reached and stay at 40 degrees F, straw should be applied. Soil temperatures can be checked with a simple thermometer. Another rule of thumb is to apply mulch after several 20-degree freezes have occurred. For most of Illinois, this usually happens between mid-November and mid-December, depending on location.
About any type of loose organic material can be used as mulch, but straw is the most readily accessible and it has good insulation ability. Avoid materials that contain weed seeds, such as hay,
as well as sawdust or chips that are too heavy and dense. Apply a 2- to 3-inch straw layer, and for
raised beds with greater exposure, apply several more inches. As the winter progresses, snow helps add even greater insulation, so leave it on the plants.
Straw should be removed in the spring when new leaf growth becomes evident in the center of the plant. Using a leaf rake, drag the straw to the edge of the bed to provide a cushion for developing berries, or into the walkway, and leave some on top to filter down between plants.
The first AgTech Conference for southwestern Illinois will include such topics as free software and online tools, the use of technology in livestock production, using spreadsheets in your farm operation, and practical application of GPS/GIS.
The conference is set for January 8, 9:30 a.m. to 3:30 p.m. at Southwestern Illinois College, Belleville.
The registration deadline is December 21, and lunch is included in the $25 registration fee. Watch for more details on the SI Agriculture website, http://web.extension.uiuc.edu/regions/ag. Or, contact Teresa Steckler, 618-242-9310, tsteckle@illinois.edu.
