Preparing Your Lawn for the Winter (Winterizing)

With the seasons changing and the weather getting cooler a lot of garden centers have been selling a "winterizer" fertilizer that is supposed to prepare the lawn for the low temperatures of winter. Until I worked at a garden center I had never even heard of this special fertilizer and chances are, unless you are an avid gardener you may not have either. Every fertilizer has a unique three number analysis correlated with the letters N (nitrogen), P (phosphoric acid), and K (potash). Other micro-nutrients may be included as well but N,P, and K are considered to be the primary macro-nutrients needed by the plant in larger quantities and they will always be displayed in the fertilizer analysis on the bag. Each nutrient serves the plant in a different way so the analysis may vary depending on plant species, available nutrients in the soil, and time of year.

A winterizing fertilizer should be looked at from two perspectives. That of cool season grasses and warm season grasses. Winterizing means a totally different things for the two. For southern warm season grasses it means trying to encourage root growth with potassium without stimulating new fleshy growth with nitrogen. For cool season grasses it means applying a higher rate of nitrogen in the early fall when the grasses are thriving. Therefore the fertilizer analysis for both will be quite different and caution should be taken to make sure you are buying the right kind for the right climate and type of grass.

A winterizer for cool season grasses might have an analysis similar to this (26-3-12) and could be applied in early to mid October. A warm season grass winterizer should look something like this (5-0-20) and should be applied no later than the end of September but preferably earlier in the month.

In southern lawns if you are following a regimented fertilization schedule throughout the year it may not be necessary to use a winterizer. It might actually just cause nutrients to be leached out of the soil and into the ground water. Because of this, some people think that using a winterizer is just a marketing gimmick and is not really necessary. I would tend to agree. At least if you are fertilizing some during the year. If you have not fertilized at all during the year than I do think that applying a winterizer could be helpful if applied in early September, but wait much longer and it could be a waste or even harmful if it has too much nitrogen.

Helpful Rousources:
Fall/Winter care for cool season grasses
Fall/Winter care for warm season grasses

Declaring War on Weeds

Walking around outside I can see many lawns that are quite nice and yet are tarnished by weeds. Sporadically located straggly weeds can ruin the beauty of an otherwise nice looking lawn. Or maybe there is a whole patch of weeds where turf is desired. Either way, weeds are not desirable and will out-compete your grass if not kept in check. Weeds can also be viewed as indicators of other underlying issues with soil or environmental conditions that need attention. The simplest definition of a weed is "a plant out of place". By this definition, a typically desirable plant like St. Augustine grass could be considered a weed if it is located in the middle of a predominately Zoysiagrass lawn. Weeds are typically very tough plants that can grow well in adverse conditions such as drought, very little soil (cracks in the concrete), poor soil quality, extreme heat, etc. This is what makes weeds so darn pesky. There are several ways to prevent and combat weeds. The best way to manage weeds is to prevent them before they can even sprout by maintaining a thick and healthy lawn. When weeds do pop up there are several options depending on the type of weed your are dealing with and the time of year.

Know Your Enemy

Weeds come in many types, shapes, and sizes. They are either warm season or cool season and can be broken down into three groups: the broadleaves, the grasses, and the sedges. Within these broad groupings, weeds can be either  annual - growing for one season and dying, biannual - growing for two seasons and dying, or perennial, growing for three seasons or more,. These groupings will help determine what methods of control and what herbicides should be used. 

A Healthy Plentiful Army is Crucial

Your army is your lawn and the more healthy and full it is, the less weeds you will have. Therefore weed control begins with the selection of a turfgrass species that is suitable to its growing environment and proper turf management practices. Proper fertilization, pest management, watering, soil drainage, and mowing will be key in keeping your army of turfgrass ready for battle. A full and healthy lawn shades the soil preventing light from reaching weed seed and causing them to germinate. In addition, thicker grass does not allow much space for weed competition. 

Weapons of War

Although not very appealing, in smaller areas, hand weeding can be a very effective method of controlling weeds. When hand weeding, it is necessary to remove root and other underground portions of the plant otherwise it may grow back. For certain annual weeds, simply mowing them off before they go to seed can be an effective form of maintenance. This type of control will not be effective in most scenarios. In relatively small areas where you are trying to remove entire patches of weeds, smothering with a tarp can be an effective option. When necessary, herbicides can be quite effective if used properly. Herbicides are categorized as either post-emergent or pre-emergent.  Pre-emergent herbicides are used to kill weeds while they are germinating before they can arise from the soil. Therefore they must be applied before the weed can even be seen. This means applying them in early spring for summer annuals, and late summer/early fall for winter annuals. Post-emergence herbicides are applied after the weeds have emerged from the soil. They can be taken up by the weed through the leaves or the roots. Herbicides are also considered either selective or non-selective, meaning that it may kill everything it comes in contact with (non-selective) or it may only kill certain species (selective). The most well known herbicide on the market is probably Round-Up which is a non-selective herbicide that kills everything it comes in contact with. This type of herbicide therefore is not very suitable where there is turf intermingled with weeds. Selective herbicides are needed to eradicate weeds from within the lawn and different types of weeds require different herbicides. Whenever using an herbicide or pesticide always read and follow the label, damage to turf as well as bodily injury can occur if they are handled incorrectly. There is a plethora of resources available online on this topic, I highly recommend looking into them. Here is a useful resource geared towards weed control in southern lawns.