Cylinder Mowers
If you want the perfect stripy lawn, you're going to need a cylinder mower with a heavy roller. Essentially, cylinder mowers give the best cut, but the lawn has to be well-trained in the first place.
The best cut
A cylinder mower (called a reel mower in the USA) is the traditional kind of mower: it has a set of sharp, scythe-shaped blades, set on a drum-like structure, which whirrs around on a horizontal axis, turning against a fixed blade. This produces a scissor-like action, which cuts the grass cleanly. Cylinder mowers were the very first kind of mower (see The History of Lawnmowers), developed from a similar device used in the textile industry to trim velvet. They give the best cut of all mowers - which is why they are used to mow the world's most carefully manicured lawns: golf greens.
Push-mowers
Simple hand-propelled push-mowers are cylinder mowers. They consist of little more than fixed blade on the chassis, the spinning blades with their axis attached to the large sidewheels, and the handle to push against. A gear and ratchet system inside the wheels converts the forward motion of the pushing into the accelerated spinning motion of the blades. Modern push-mowers are efficient, and ideal for small gardens; they have the best carbon footprint of any mower, and think of all that exercise you’ll get! The simplest push-mowers are not fitted with a box to collect the clippings, but some models are (see "Box or no box?" below).
Petrol or electric?
Petrol-driven cylinder mowers are really the Rolls-Royces of all mowers. The best are superb machines, and expensive with it. Electric cylinder mowers are lighter and less powerful, but cheaper – and perfectly adequate for most small gardens. For the debate over which power-source to use, see the separate article on Petrol or Electric?
Roller
Many of the larger cylinder mowers, especially the petrol-driven ones, are fitted with a heavy roller. This is what produces that striped look, which is so closely associated with the classic British lawn. The light-weight plastic rollers of electric cylinder mowers won't have the same effect, despite what some manufacturers will tell you.
Height adjustment
By adjusting the height of the cutting blades, usually with simple levers, you can adjust the length of your grass. As a general rule, for the health of your lawn (especially in dry weather), you should not cut the grass very short; rather, cut it to medium length (2-4 cm). Which means you will also have to cut it more often. But that’s a good rule to go by: mow your lawn little but often.
Box or no box?
Most cylinder mowers (except small push-mowers) come with a detachable collecting box (or grass box), which gathers the grass clippings as they are thrown forward by the cutting action. This is a useful asset: without a box, you may have to rake up the clippings. But this is not necessarily essential. You can just leave the clippings scattered on the ground. Grass-clippings contain valuable nutrients and can help a lawn to retain moisture - particularly valuable in dry spells. But you can have too much of a good thing: you don't want the grass-clippings to create a mat of debris on the lawn, which could damage the health of the grass and invite disease and fungi. And you may not much like people tramping clippings into your house, either. A good compromise is to collect and discard (or, better, compost) clippings from the spring mowings, when the harvest is copious, but leave them scattered (i.e. mow without the box) when the clippings are short, typically when you are mowing once (or even twice) a week in the summer.
Stay sharp
If your mower blades aren't sharp or properly set, you can damage the grass by crushing and bruising it instead of cutting it cleanly. Blades get blunt by cutting, or chewed up when they hit stones. At least once a year, you should get your blades sharpened by a professional sharpener; or you can try doing this yourself with a file or carborundum stone. At the same time, check that the blades on the cylinder meet the fixed blade (or 'bottom blade', or 'bed knife') right the way across its length. You usually can regulate the position of the bottom blade with screw adjustments, or 'click adjusters'. A well sharpened and properly adjusted set of cylinder blades should be able to cut a sheet of paper cleanly along the full width of the bottom blade. Meanwhile, you should regularly clean the mower of dead grass and debris, and oil the moving parts.
Gang mowers
The big open areas of grass in parks and sports grounds can be maintained by a set of three, five or seven cylinder mowers, towed behind a tractor. In the classic kind of gang mower, the axis of the cylinders is connected to the sidewheels, as in simple push-mowers. The cylinders are not fitted with boxes, and so the grass clippings are left uncollected; if the grass gets too long before it is cut, the clippings will form a thick mat which can be both unsightly and damaging to the living grass beneath. Again the mowing mantra applies: little and often.