P U B L I S H ED IN FEBRUARY, MARCH, APRIL, A U G U ST A ND SEPTEMBER BY O. M. SCOTT & SONS CO., MARYSVILLE, OHIO February 1941 F O U R T E E N TH YEAR Number 63 HOW WINTER AFFECTS GRASS THE day has again arrived to start tracking down the neighborhood lawn roller. In many instances this itinerant tool strays so far from home that it winds up behind the garage of a total stranger. While in a searching frame of mind, it is a good time to examine and diag- nose the damage winter has wrought to the lawn around your home. injury "Winterkill" is a term used all too frequently to explain any win- ter to lawns regardless of what the cause may have been. Asked to define it, most folks would have a difficult time but in a general way they probably associate it with cold weather. Actually cold weather, even when the mer- cury is huddled "Hi, neighbor! I'll for your below zero, does not in itself harm good lawn grass. The plants go into cold storage and some- times lose their color but they continue to live and breathe. A well fed, sturdy sod can stand all the extremes of tem- perature the weatherman can dish out. Some lawns are badly riddled in winter because they were sown in the spring with annual types of grass. These suc- cumb to the first real winter weather, the same as all annual plants. Of even worse appearance are those lawns in- fested with Crabgrass. Effect Of Freezing And Thawing Even good lawns are sure to suffer some injury over the winter months. It isn't the cold that harms them, it's the warmth; that is, those un- seasonable days when the ground thaws. Then at night the soil which is usually well saturated with moisture is apt to freeze again. As it does the crystals of ice expand and force apart the soil crumbs. During the next thaw the ice melts and the soil settles back, leaving the roots par- tially out of the ground. After this process has been repeated a few times many grass plants will be heaved to such an extent that the roots are broken off or exposed to drying sun and winds. Plants need moisture even in winter and they are soon destroyed if they cannot take it from the soil. swap your snow shovel lawn roller!" COPYRIGHT 1941 BY O. M. SCOTT & SONS CO. Because of this lifting or heaving of turf by alternate freezing and thawing, an open winter may be more damaging to grass than the so called old fashioned winters. Good grass is better ofi if it remains frozen all winter especially if it lies buried under a protective blan- ket of snow. Harmful efiects often result from trampling over unprotected grass in cold weather. Coasting and skiing leave no scars on lawns well covered with snow, but just walking on frozen, brit- tle grass that has no covering will leave footprints for months to come. Insulating Against Thaws Grass that goes into the winter in a strong, vigorous condition will be lit- tle affected by adverse weather. A thick sod is highly resistant to frost action because the fibrous roots bind the sur- face soil together and reduce heaving. A taller growth of grass shades the sur- face of the soil, thereby reducing the amount of thawing on mild days. The use of a winter mulch is not ordinarily necessary but it is sometimes beneficial to young grass that did not get much of a start before cold weather. Areas having a direct southern ex- posure and consequently an unusual amount of freezing and thawing may also be benefited. Such a mulch is not placed to protect the grass from freezing but to insulate the ground against unseasonable thaws. It should therefore be put on after the ground has frozen and should be scat- tered to a depth of 1 or 2 inches. This is easily raked off in the spring after the grass starts growing. Only clean straw should be used in order to mini- mize the danger of introducing weeds. First Aid In The Spring Any lawn will benefit by early spring attention but especially one which has had a hard winter. The dead plants will need replacing. Food reserves that were exhausted over the winter will need replenishing. An ideal time to do this is while the alternate freezing and thawing of the soil is in process. This action of Mother Nature leaves the soil in a honeycombed condition with millions of tiny cracks and crevi- ces. Into these the grass food will fall and easily penetrate to the root zone of the lawn. Seed may also find its way into the soil openings. It will be cov- ered naturally and will be ready to burst into life as soon as the ground warms. In addition to feeding and reseeding in the the lawn, first aid treatment spring should include rolling. Best Time To Roll When to roll and how heavy a roller to use are both matters of prime impor- tance. It is damaging to soils to foil them while they are soaking wet and just as damaging to use a roller so heavy that it actually mashes into the ground. The soil should be moderately moist and a roller of water or sand ballast type used, so the weight can be adjusted to the soil condition. Some lawns newly planted in late fall or dur- ing the winter have only a short growth of seedlings by rolling time in the spring. Even so, if the ground is badly heaved it should be rolled. Weight Of Roller The heavier and wetter the soil the lighter the roller should be. A sandy soil can withstand more weight than a clay soil. As a general rule a ballast roller should be less than one-half full so the weight is around 75 or 100 pounds per foot in width. If in doubt use a very light roller or none at all. There is a mistaken idea that the func- tion of rolling is to level or iron out high and low spots in a lawn. To attempt this is only courting trouble since such a severe rolling will puddle and compact the soil so the grass roots are suffocated.