Lawn Mowing and Mowers
On a well kept lawn, mowing takes up more time than any other operation. Unfortunately on many lawns it is the only treatment given. Since mowing is done perhaps forty or fifty times a year, obviously it must have a marked influence on the nature of the sward. It is mowing, infact, that determines the botanical constitution of the turf, since it really amounts to a process of constant pruning, which some plants can tolerate whilst others cannot. Most tall growing and tufted grasses gradually disappear, while garden weeds (for example, groundsel, fat-hen etc.) either fail to gain a foothold or where present, as in some new sown swards, soon die out. The bottom grasses like bent, fescue, crested dog’s tail, annual meadow grass, and unfortunately Yorkshire fog are adaptable to mown conditions and persist.
It is mowing also that largely determines the kinds of weeds that persist; for example rosette weeds like dandelion, the plantains, and the daisy and creeping ones like pearlwort, yarrow, white clover, creeping buttercup, and mouse-ear chick weed.
Mowing at long intervals is harmful to the lawn and the first principle of mowing should, therefore, be to do it often. Spasmodic on the amount of growth. This in turn is influenced by soil and weather conditions. At the height of the growing season, May and June to have to mow twice or even three times a week is not unusual, but the number of cuts required will be less in dry weather and in spring and autumn. A light top during early winter is sometimes needed. This helps to keep check the coarser grasses, such as perennial rye grass which have a longer growing season and would otherwise start growth the following year with a great advantage over the dwarf grasses.
Close ‘shaving’ of a lawn is to be depreciated. Very close cuts demand a very true surface, otherwise slight undulations are easily scalped by the sole plate of the mower. While it is true that cricket wickets may be cut down to 1/18 in. that is far too low for an ornamental lawn, where ¼ to 3/8 in. is likely to give the best results. On utility lawns designed for rougher use ½ to 1 in. is quite short enough. On all lawns a little more grass should be left in dry weather, while in autumn and spring cutting should not be as short as it is in the summer. Lawns that are cut regularly two or three times in a week, but not shaved, thrive much better and are more resistant to weeds, particularly pearlwort and the mosses. Infrequent mowing damages the grass, opens it out and thus favors weed invasion. The ideal is to keep the lawn as near as the desired height as possible, never allowing it to get away.
The majority of mowing machines are fitted with a scale by which the height of cut can be adjusted, but such scales are not always accurate, especially on old machines. Therefore, the best way to check the height of cut is by a straight edge placed across front and rear rollers of the machine. With a sidewheel machine the straight edge is laid across the rear roller and the lowest point of each driving wheel in turn. The height of cut is then measured as the distance from the straight edge to the cutting edge of the bottom fixed blade. This distance can be measured by penny thickness (a penny is approximately 1/16 in. thick) or by rule. Naturally each side of the mower should have the same setting, otherwise an uneven cut results.
Many gardeners worry about whether or not they should remove the clippings in the box. Under normal conditions the rule should be to remove them. A firmer turf results in this way and earthworm invasion is likely to be less. In dry weather the rule may be varied by allowing the cuttings to fly, since they soon wither up and may have a slight mulching effect. Removing the clippings does, of course, tend to rob the soil of plant foods, especially nitrogen. A good plan is to rot the clippings, make them into a compost with soil and distribute the product as a screened top dressing a year or two later, thus returning organic matter and some of the plant foods.
A great many lawn owners cut their lawn on a ‘push-pull’ basis, but continuous mowing in parallel strips with turns at the end gives best results with best finish. It is also less harmful to the mower and better for the man behind it! The direction of mowing should be changed in successive mowing. Even if the shape of the lawn makes this inconvenient in one direction, nevertheless, cutting in the awkward direction should at times be done. There is a tendency on long narrow lawns, when mowing generally one way, to produce a wash boarding effect, especially if a motor mower is used.
Regularly mown and dressed lawns have a tendency to develop a layer of semi-decayed material in among the shoots. The amount of this is seldom realized until a good scratching is done with a wire rake. The best plan is to rake fairly vigorously in spring and to mow off. Then the raking may be done occasionally, say monthly, during the growing season. This process helps to encourage a stronger and denser turf to form.
Drag brushing is another operation useful before mowing, since it has a light scarifying effect and helps to drag up straggly stems to meet the mower. The process is useful for scattering dew or worm casts. A damp lawn sticky with worm casts leads to mowing troubles thorough the material sticking to the rollers.
It is perhaps fitting at the start to refer again to the first lawn mower. Edwin Budding, the designer, patented it in 1830 and in the course of specification he said: “Country gentlemen may find in using my machine themselves an amusing, useful, and healthy exercise”
Today there is a remarkable range of mowing machines designed for various purposes and for different sized areas. For most lawn owners the choice lies between the roller and sidewheel hand mowers and conventional motor mowers or machines where the cutting cylinder can be driven by power while machine may be pushed. A refinement of this is where either cutting cylinder or land roller can be powered at will. Electric mowers have their advocates. The trailing cable may be a disadvantage, although many people find, with practice, it is no trouble. The size of the lawn and the amount of money available are likely to be ruling factors on making a decision on what to buy. A hand roller mower capable of cutting up to the edges will generally suit the average small lawn. The number of blades and their speed of rotation decides the cuts per square yard. Thus the average inexpensive mower gives from above 40 to 50 cuts per yard, but a high class precision mower will have about 100. The chosen machine should be close coupled; that is, the distance between the front roller and the cutting cylinder should be as short as possible so as to reduce the risk of skinning.
A sidewheel machine is more efficient than a roller mower when the lawn has been scarified, since there is no front roller to press down the stems which have just been raked up by the rake. Roller machines are best for verges and lawn edges. For large lawns, obviously a powered machine is desirable. In purchasing it is best to avoid excessive weight since this leads to soil compaction.
Mention must be made of powered rotary mowers where the cutting is done by fan like blades running horizontally which flick off the grass, there being no bottom sole plate. These machines are popular for semi rough areas, for example orchards.
Having chosen a sound machine to suit the purpose desired it is important that it should be kept in good condition. Small faults lead to damage and perhaps a serious breakdown. The mower should not be bumped over kerbs or steps as this may knock up the bottom blade against the cutters, or even result in a breakage. Tight setting of the blade on to the cutters or over low cutting will lead to excessive wear. In all cases when mowing the hand pressure should be forward, leaving the machine free to find its own level and many machines have a ‘floating’ handle that encourages this.
After use mowers should be brushed or washed down and then dried and wiped over with an oily rag. During the season, apart from greasing, little more than occasional adjustment of cutters to sole plate should be needed. Heavily used mowers may need light grinding in but most owners of small lawns will have this done for them by the makers or their agents during the winter months.