Lawn care FAQs

What is the best kind of mower to buy?

Buying mowers is like buying cars—there is a choice of many kinds and many prices. For a domestic lawn of say, 100 m (120 sq yd) a good quality 300-350 mm (12-14 in) hand mower of the traditional cylinder type and fitted with grass box is suitable. You may have to shop around for this: the fad nowadays is for powered motors (with petrol or electric engines) and with rotary cutting blades, and among these the hover types have been especially heavily promoted. Some machines, of whatever type, have grass-collecting attachments and some have not. From the various types of mowers available you make your choice and pay accordingly. First-class lawns, however, need a cylinder mower (roller type with grass box) which gives 100 cuts or more per metre (yard) run.

How is the height of cut measured?

It is not practicable to measure the actual height of the grass because fixed points are difficult to establish. Instead heights are described in terms of the mower setting. With a cylinder mower the height of cut measured is the distance between a straight edge laid from front to back roller and the cutting edge of the bottom blade. With side wheel mowers and some rotary mowers the straight edge is laid from roller to side wheel.

How often should I mow my lawn?

The aim is dense turf with an attractive appearance, so the grass should be cut whenever it visibly exceeds the norm: see next answer. For very fine lawns this may mean mowing two or three times per week at the height of the growing season, though once per week suffices for the average lawn. When growth is slow, less frequent mowing is needed—a good reason for not using too much fertiliser.

Is there a best height at which to mow a lawn?

For each kind of lawn the answer is probably yes. The heights of cut suggested are: finest quality (Type 1) lawns, 6-13 mm (¼ – ½ in); average quality (Type 2), 13-19mm(½-3/4in);and general purpose (Type 3), 19-25 mm (¾-l in).

I do not have a grass box on my mower. Should I remove the cuttings from the lawn after mowing?

There are pros and cons to removing cuttings. Leaving them on the lawn means that mineral nutrients are returned to the soil, and the organic matter of which they mainly consist helps drought resistance. However, they release their mineral nutrients only as the organic matter decomposes—and decomposing organic matter is good earthworm food; so leaving the cuttings encourages earthworms with their unpleasant casting. It also helps to spread weeds, and may encourage disease. So, on balance, it is better to remove the cuttings.

It seems to be common practice to put away lawn mowers from October to April. However, since my lawn grows during some parts of this period, should I cut it occasionally?

If the grass gets much beyond its normal height it may be harmed if you do not cut it. Provided the weather is right—look for a mild and preferably dry spell—it is beneficial to mow whenever there is grass to mow; but do not cut it as short as in the summer.

Can I use growth retarders on my lawn instead of mowing it?

Available growth retarders (based on maleic hydrazide) are apparently quite effective on privet hedges but only moderately successful on lawns. Their use has to be skilfully organised to achieve any kind of success; they often cause considerable discoloration, and the turf does not look as smart as when it is mown. Reducing grass growth helps weeds to flourish, so if you use a growth retarder you may need to combine it with a selective weedkiller.

Should I roll my lawn occasionally?

If possible, no. Rolling is harmful because it causes soil compaction, which spoils the drainage qualities of the soil, and it restricts aeration, which leads to poor root development and a weaker turf.

Do I need to rake my lawn?

Most lawns benefit from brushing with a stiff broom or raking with a wire rake about once a month to remove debris. In spring and summer, this should be done before mowing. In autumn, scarifying (vigorous raking out of debris) is also beneficial. Remove rakings with a stiff broom if your mower has no grass box.

How do I maintain neat lawn edges?

The main needs are regular trimming with shears or special edge trimmers, avoiding treading on the lawn edge, and siting plants in adjacent beds far enough away to avoid them overhanging the lawn.

Long edges should be given permanent support. Metal-strip edging is cheap and effective; timber and concrete are longer-lasting. The top of such edging should be a little lower than the surface of the lawn so that you can mow right up to the edge. If no edging is used, you can maintain straight edges by trimming with a spade or ‘halfmoon’ against the edge of a long plank.

Can I grow bulbs such as daffodils and crocuses in my lawn?

Bulbs will certainly grow in a lawn and can be very attractive in the spring. Unfortunately, their growth conflicts with mowing requirements: if the turf is not mown regularly it deteriorates, and if the bulbs are mown they cannot thrive. Planting the bulbs in not too plentiful groups or drifts minimises the area of lawn affected.

Should I water my lawn?

Watering is beneficial if done properly and not overdone. In really dry weather give the lawn a good soaking and then allow several days partial drying out before repeating.

How often should I apply fertiliser?

Fertiliser requirements vary depending on soil, grasses present, whether cuttings are removed, and so on. Good, fine grasses such as fescues and bents are poverty grasses: in nature they typically occur on areas of low fertility such as moorland. Making the grass grow faster increases the amount of mowing you will have to do. Lawns receiving little wear may require a general lawn fertiliser only once every 5 to 10 years. Heavily worn lower-grade lawns may require feeding with balanced fertiliser at least once a year; so too may fine-grade luxury lawns. The chief mineral nutrient required by turf is nitrogen. If there is reason to suppose that the other main nutrients (phosphate and potash) are in reasonable supply but that the grass is not growing vigorously enough, especially in the spring, you should give it a dressing of nitrogenous fertiliser, such as sulphate of ammonia at 18 g/m2 (½ oz/sq yd), diluted with a spreading agent .

How can I ensure that the fertiliser is spread evenly?

For many people spreading by hand is simplest and best. The fertiliser should be well mixed with a spreading agent such as compost, allowing about 280 g/2 m2 compost (8 oz/sq yd). If the total amount is halved then one half can be spread lengthways and the other crossways. Alternatively, especially for large lawns, the area can be divided into a number of measured squares and the material rationed out equally for each square.

Fertiliser distributors are of two types: linear distributors, which use rollers to transfer fertiliser from a hopper to a broad band of turf; and spinners, which spread by means of a quickly revolving plate. With either type it may not be strictly necessary to dilute proprietary fertiliser with compost but it is still a good plan. It is also wise to divide the fertiliser into two and spread it in two applications at half rate. With a linear distributor the two applications should be at right angles; with a spinner they should be in the same direction but overlapping because the spinner applies more fertiliser in the middle than at the edges of its spread. With any distributor particular care is needed during filling and turning.

The quantity marks on my fertiliser distributor do not seem to match the amounts it applies. Why is this?

Materials vary in density and in ability to flow, so the marks on the distributor aim at an average. The best way to calibrate the distributor for a particular material is to fill the hopper and run the machine at working speed over a measured sheet or tray. The amount distributed can then be weighed and any necessary adjustments made to the machine setting before lawn use.

What are the advantages of applying fertiliser in solution?

Except for convenience, very few. The need for solubility restricts the kind of fertilisers which can be used and those which are compatible and suitably soluble are not necessarily the best for turf. If it is applied as a spray the solution has to be applied very carefully to avoid the grass being scorched. If it is watered in, the dilute solution tends to find the lower and softer spots least in need of fertiliser.

I have been advised to apply lawn sand to my turf. What exactly is this material?

Lawn sand is a mixture of chemicals and sand used to promote grass growth and burn out weeds, including moss. A typical formula is 3 parts sulphate of ammonia, 1 part calcined sulphate of iron, and 20 parts fine sand. This mixture would be used at a rate 140 g/m2 (4 oz/sq yd). Proprietary lawn sands are very useful, although the advent of selective weedkillers and the new mosskillers has much reduced their popularity. Unfortunately the term ‘lawn sand’ is used to describe the sand used (without chemical admixture) as a top-dressing to smooth out the surface of the lawn. Top-dressings are used at heavy rates—2 kg/m2 (4 lb/sq yd) is typical—and the use of a true lawn sand at this concentration would ruin the lawn.

Where the chalk lines are marked out on my lawn tennis court the turf seems much greener and more vigorous than the rest of the lawn. Does this mean that my lawn needs lime?

It does not follow at all. If you have a good lawn it is probably wise to leave well alone since lime encourages coarse grass, weeds, worms, and disease! You may see evidence of this near the chalk lines if you examine those areas carefully. It is possible that your lawn needs lime, but a laboratory soil test is the best basis on which to form an opinion. Most good lawns are found on slightly acid soil.

There is a bewildering range of selective weedkillers available for treating lawns. Is any one type better than the other, or are they all effectively the same?

They are all useful if used strictly in accordance with the instructions on the labels; but they are by no means all the same. There are at least four chemicals used in these weedkillers either singly or in combinations (usually of two). Each of the chemicals is effective against some weeds but not others, so that combinations deal with a broader range of weeds than do single-chemical formulations. Different combinations deal with different ranges of weeds, so read the labels carefully to make sure which weedkiller most nearly answers your needs.

What is the best way to apply selective weedkillers to a lawn?

For a typical small suburban lawn apply the prepared solution by means of a watering can fitted with a fine rose or with a dribble bar. For large lawns you could try a roller-type applicator, which feeds the diluted weedkiller from a tank mounted on the frame so as to wet the special roller which in turn wets the foliage as it passes over the turf. Spraying is not recommended because of the risk of spray drifting onto the rest of the garden (and even into your neighbour’s).

Combined fertiliser/weedkiller powders or granules used carefully are often useful—they produce two effects from one effort!

My large lawn has only a few scattered weeds. How can I get rid of these without treating the whole lawn with selective weedkiller?

There are various ways of doing this—including hand weeding! The safest chemical way is probably to make up a correctly mixed watering-canful of a broad-spectrum selective weedkiller and, using the rose, to sprinkle each weed lightly, trying to avoid excess. You can always repeat the treatment a week or two later, whereas grass damaged by excess weedkiller may take many weeks to recover.

So-called touchweeders are useful against many lawn weeds— they consist of weedkilling chemicals in a piece of softish wax with which the weeds are touched quite lightly; rubbing them hard results in very brown or dead grass. Small pressurised containers of selective weed-killer are also available—but again it is very easy to apply an overdose. Spot treatment involves only small patches, so that excessive applications do not kill off the whole lawn; but there is less danger of excess if the correct amounts of weedkiller are neasured out and applied to the whole area.

What is meant by the term top-dressing?

In horticulture top-dressing usually means applying a fertiliser, particularly a nitrogenous one, to the surface of soil bearing a crop, usually in concentrations of about 18 g/m2 (½ oz/sq yd). In lawn management top-dressing means the application of suitable bulky material to the surface of the lawn at the rate of 15 ½ kg/m (2 ½ lb/sq yd), and then working it in by means of suitable equipment such as a drag brush with a view to making the surface smooth.

What kind of material should I use for top-dressing my lawn?

Although some gardeners use them, pure sand and peat are both unsatisfactory because they produce layers which form moisture and root breaks. Make up a synthetic compost if you are unable to buy suitable stuff ready-made. For this the sand should be of medium grade, with a particle size range of 0.5-0.125 mm, it must be stable (not break down into smaller particles, for example) and it should be lime-free. A suitable mixture would be 6 parts of this sand, 1 part granulated peat, and 3 parts topsoil.

From my garden waste I have made a heap of compost resembling well-rotted farmyard manure. Would a top-dressing of this be good for the lawn?

No: it would be far better used for vegetables and flowers because it would encourage worms and weeds in the lawn.

How often should a lawn be aerated?

Regular aeration is usually essential for sports turf since the top soil becomes compacted by heavy use and possibly by rolling. Many lawns receive very little treading and no rolling so that they seldom need any mechanical aeration at all. If a particular lawn or part of a lawn, does get well trodden, spiking by hand or machine could be beneficial two or three times a year. For such areas hollow tine forking, which is very efficient at relieving top-soil compaction, could be done at a frequency of once in three years—over frequent hollow fining leads to excessive softness and to weed invasion.

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