Lincoln had bitter cold temperatures during the first two weeks of November and then cold temperatures from late December through mid-January. Nebraska has been fortunate to have escaped the endless string of cold temperatures we experienced last winter. According to Al Dutcher, Nebraska state climatologist, “The temperature outlook for February contains considerable uncertainty as the Climate Prediction Center shows no climatological trend for Nebraska. CPC suggests a weak tendency in the 90-day outlook for below normal temperatures across southwest and south central Nebraska, with no distinct trend indicated for the remainder of the state....Colder than normal temperatures, above normal moisture (including snow) occurs a little over 60% of the time for Nebraska during the March-May period, with the highest probabilities assigned to the western half of the state. It remains to be seen whether these conditions will occur this winter.” (“Weather Outlook Uncertain, but Storms Could Lie Ahead” by Al Dutcher, Cropwatch for January 20, 2015, University of Nebraska-Lincoln,

          For gardeners in Nebraska, what do we need to do when we have such uncertain predictions? The reality is, this is the usual prediction for the central plains states. We are never certain what the weather is going to be. Will it be a wet, cold spring or will the above average temperatures continue? Will we have an early fall or will we have above average temperatures until Thanksgiving? Will it be a mild winter or will we have below average temperatures with lots of snow next winter? 

          The common myth is that we mulch our plants in the fall to keep the ground warm to protect our plants. The truth is we mulch in late fall to keep the ground cold. More winter hardy plants are killed by the freezing and thawing during the winter than from the cold and below average temperatures. So we want to put the mulch on the soil after a couple of hard freezes (temps in the low 20’s). My wife usually does not cover our roses until after Halloween. In northern climates such as North Dakota and Minnesota where it snows and the snow stays all winter, some plants do better because the snow insulates the ground all winter and they do not get the freezing and thawing.

          Gardeners who put their mulch on too early in the fall do not allow the ground to cool down normally and thus the plant does not go into dormancy naturally. And don’t remove your mulch too early in the spring. Most gardeners can remember a warm spell in March? We have had a number of them over the years. Plants that were not properly mulched or had their mulch removed too early, warmed up and some broke dormancy. Then when we got a cold spell in April they could not go back into dormancy and froze. If you don’t remember ask your grandmother. The rule is-don’t put mulch on too early in the fall or remove too early in the spring. 

          What is the best mulch? Each gardener has his or her favorite. Gladys uses lots of compost from her huge compost pile. I use wood chips or shredded hard wood on my roses, shrubs, and other perennials because I have access to it. I do not recommend using CyprEss mulch from an ecological point of view. CyprEss trees are being clear-cut from our native wetlands to make way for business and housing developments in Florida and the destroyed CYPRESS TREES are not being replanted. According to the Florida Cooperative Extension Service, the old idea that CYPRESS mulch is superior to other mulches is not true anymore.  The old-growth CYPRESS harvested prior to the 1950’s had a reputation for being rot-and termite-resistant. But all those old, old trees have all been taken except for a few saved in our nature preserves. Now CYPRESS mulch comes from trees that are too young to develop that property as it takes hundreds of years for the chemical to form inside the tree. Also science has found that the proper hydrology for CYPRESS seed germination is difficult and rarely accomplished by anyone but Mother Nature. Some counties in Florida have restricted the use of CYPRESS mulch because its harvest degrades CYPRESS wetlands. CYPRESS works o.k. as mulch in your garden, but the destruction of these forests is not good for our environment.

So what do we recommend? RED Cedar mulch usually comes from Cedar Tree nurseries and the trees are grown just for the mulch. The trees grow fairly rapidly and are quite often on land that is not much good for anything else. Hardwood mulches usually come from trees that had to be cut down for one reason or another and would have ended up in the landfill or burned if not ground up. Recently hardwood mulches have been dyed red, gold, and dark brown. Most dyes do not hurt your soil. Pine needles, pine bark, and shredded evergreen wood all make an excellent mulch.

I use compost on my raspberries, asparagus, rhubarb, and in the flower garden. Some gardeners use shredded leaves and grass. Do not use leaves that have not been shredded by a grinder or your mower, or grass clippings that have not dried out for a couple days. These tend to mat down and not allow water to penetrate. Also, there are too few air spaces which are needed for good insulation.

          Also, do not use those foam cones unless you cut the top out. Then fill the inside with mulch, compost, or soil. On a warm winter day the heat builds up inside a cone that has the top still on it. This can heat on a warm winter day or in the early spring, can cause the plant to break dormancy and start growing. With the next hard freeze the plant then freezes and dies. The cones are easy and convenient to use, but they do not work.

          The main reason I wrote this article is to encourage you to go out now and check your mulch. If the strong Nebraska winds have blown some away, replace it. If you did not put enough on to start with, do it now. It is not too late to protect your plants from the freezing and thawing this spring. Remember, mulch in the winter to keep the ground cold, and mulch in the summer to keep the roots cool, the ground from drying out, and to suppress weed growth.

Copyright 2015