MAINTENANCE 87 



preparation to emerge as adult beetles they may be crushed by rolling 

 the lawn with a ten-ton roller, but failing this heroic treatment, there 

 seems to be. no simpler remedy. 



MOWING LAWNS. Mowing of lawns should be governed by the use 

 to which the lawn is to be put. Mowing should not be very frequent 

 in hot weather nor very long neglected at seasons when the grass is 

 growing rapidly. Clipping should cease before the grass stops grow- 

 ing in the autumn, so that a long growth may be left on the lawn over 

 winter. A portion of the clippings should be left on a lawn to act as a 

 mulch, especially if the grass is cut often. Enough grass leaves 

 must be left on each plant so that it can maintain its growth, but on 

 the other hand, growth must not be carried to the point of seed pro- 

 duction, which, more than anything else, tends to weaken the vitality 

 of a plant. About two inches is the height most often recommended 

 for grass. It is best to leave mower knives set high and mow more 

 frequently rather than to allow grass to grow high and then cut it low 

 and thus remove too large a portion of the leaf surface of the plant, and 

 also expose the soil to the direct rays of the sun. When a lawn becomes 

 run down it is generally better to remake it entirely, instead of wasting 

 money on patching. It is well to consider that if the original grass 

 could not succeed on the soil, new grass will certainly fail. 



PERENNIALS WINTER PROTECTION. In general, the better es- 

 tablished a perennial is, the less winter protection it requires. How- 

 ever, even though plants would winter over safely if uncovered, they 

 should be protected from the heaving which follows alternate thawing 

 and freezing. In the case of perennials planted in the autumn this is 

 exceedingly important for the first winter. Snow is a good protective 

 covering, but it is rarely that plants will be so covered during the entire 

 winter. It is accordingly advisable to apply a mulch. 



Mulching in the fall provides an opportunity for fertilizing as well as 

 protection, especially if good straw manure is used. Straw or corn- 

 stalks provide excellent mulch for perennials but both encourage mice. 

 These pests may be killed by poisoned wheat or by pouring carbon 

 bisulphide down their burrows. Where mice are especially trouble- 

 some, a compost of leaves, sawdust, lawn rakings, etc., should be used, 

 inasmuch as heavy litter or one containing grain is ideal for attracting 

 animals. Perennials such as lilies, whose crowns are completely under- 

 ground, require the greatest protection. Perennials such as primroses 



