Post category: Lawns
Fairy rings are visible as rings of green, vigorous grass, often with dead patches, that sometimes produce small brown mushrooms as well. The ring is caused by a fungus in the soil. Fairy rings are usually only a problem on good, long-established lawns. Control is difficult. Applying fertiliser, except on the ring itself, masks the problem, and is the best solution in a domestic garden.
Fairy ring in a lawn
Inkcaps and other toadstools arise from bits of rotten timber and other organic material in the soil. When this material finally rots away the toadstools no longer appear. Toadstools are not, strictly speaking, a lawn disease and can be crushed or simply brushed away.
Other diseases sometimes cause yellow, brown or dead patches in the lawn. These are most serious on fine grass mixture and damp, starved lawns. If there is a reddish tinge, caused by red thread disease, on the dying grass, or white growth caused by fusarium, when examined closely, a spray with a systemic fungicide will help.
Leatherjackets often eat grass roots and can cause thin patches. Treading on the affected patches when the soil is reasonably dry helps to control them. In a bad attack, the affected areas can be covered with black polythene for about 36 hours and taken off just before dawn to let birds attack the grubs that have come to the surface. This can be repeated.
Birds, such as starlings and crows, often pull out bits of grass to get at the leatherjacket grubs. This damage is minimal and the birds help to control the grubs.
Earthworms are not a pest in gardens – as they can be on golf greens. If casts are considered unsightly, just brush them away. Dogs may foul lawns and cause scorched patches.
A neglected lawn can be brought back to a reasonable condition by mowing and feeding, weed and moss control, as described in Mowing, Feeding, Weeds and Moss.
A raised bump skinned by the mower
If a lawn was laid level originally, and the level is still good, it is not worth digging it up to make a new lawn. It can be restored. Clear any debris. Use a rotary mower without a grass-bag, or a strimmer, to cut the heavy growth. Rake off the mown grass. Tear out old grass and moss with a rake. Mow again. Apply a spring lawn feed.
Begin regular mowing. Apply lawn weedkiller two or three weeks after feeding in spring. A repeat application of lawn weedkiller might be necessary, and feeding should also be repeated. Moss control may be necessary. Top-dressing and re-seeding overall will help to restore the sward. Then simply maintain routine lawn care.
Bare patches are generally caused by wear, disease, dogs, petrol spillage or they can be caused when weeds and moss are killed off. In a new lawn, uneven sowing or bad germination may leave bare spots.
Lifting lawn sods to remove a bump
In March/April, or September/October, fork the soil surface lightly until the top 5 centimetres is loose. Add a thin layer of moist peat and/or fine soil. Level this out. Sow seed at 30 grams per square metre. Criss-cross the patch with string on pegs, to give it a chance to recover. Thin patches can be treated in the same way.
To repair bumps and hollows, cut and lift the sod. Add, or take away soil, as necessary. Replace the sod and firm it down. The sod re-establishes better if this is done in autumn. For minor hollows, the top-dressing technique described under Feeding is an adequate solution. Repeated over a few years, the hollows will fill up.
Moss thrives where there is dampness. Conditions of poor drainage, compacted soil, heavy soil and shade encourage moss. Avoid siting the lawn where there is dampness or shade. Consider planting such areas with suitable shrubs.
Starved grass, and grass weakened by too tight or irregular mowing, cannot compete with lawn moss. Feed the lawn and mow correctly as the first step to control. Scarifying, by heavy raking or a hired scarifying machine, encourages the grass and dries the soil surface. This can be carried out in autumn or spring.
Chemical mosskillers, such as Lawnsand, sulphate of iron, Mosgo Lawn Mosskiller and Bayer Mosskiller and Lawn Tonic will control moss, but if the conditions remain the same, it will recolonise the area.
Mosskillers are useful for giving the grass a once-off chance to recover while correct mowing and feeding are carried out. On chronically mossy areas, repeat applications will be necessary every year, or every few years, depending on the extent of the problem.
A few weeds in a lawn are no great problem – indeed, it can be quite attractive to have a few daisies! However, a heavy infestation by weeds, such as daisies, clover or speedwell can squeeze out the grass, spoil the look of the lawn and reduce its ability to withstand wear.
One day after spraying, daisies curl up to die
Weeds cope better than grass with low levels of soil fertility. Starved grass is susceptible to competition from weeds, so feeding the lawn is essential. Irregular ‘scalping’ of the lawn opens the grass sward and allows weeds to become established. Too tight mowing weakens the grass and this also gives weeds a chance.
Daisies and most other lawn weeds can grow flatter than lawn grass and thrive on tight mowing. Regular mowing, using the grass-bag, prevents existing weeds from seeding and spreading.
When weeds have become too dominant, a chemical lawn weedkiller can be used to help restore the balance, but feeding will be necessary as well. A variety of lawn weedkiller products is available. Use a product contianing the active ingredient mecoprop to control clover.
These contain similar active ingredients and are best applied in fine, warm weather when growth is active. April, May and June are ideal, but they can be applied between March and September after warm weather when the soil is moist. Feeding the grass two weeks before application improves results.
Combined feed and weed products work well and have the advantage of convenience, but they can be expensive if a large area has to be treated. The weedkilling function only works well in warm weather.
Lawn sand is a traditional lawn tonic combining feeding and weed suppression. Twenty parts clean sand, 3 parts sulphate of ammonia and one part sulphate of iron is the formula. Ready made lawn sand products are convenient to use.
Speedwell has pale blue flowers in April. It is quite difficult to control. Lawnsand will give some control.
Mind-your-own-business or baby’s tears, or helxine is a common weed of shady, damp corners. It spreads over the surface of the soil swamping grass and will even climb over damp stones. Use lawn sand.
Apart from feeding, the secret of a good lawn is correct mowing – frequent, regular mowing, starting early in the year and finishing late.
Start in late February or early March. Around that time there is usually a dry spell when the ground is firm enough and the grass dry enough to cut. Continue mowing at fortnightly intervals until May, when weekly mowing becomes necessary.
Regular mowing is the key to success
Mow frequently and there will be less grass to remove each time. Continue weekly mowing through the summer, except in hot, dry weather, when growth eases off.
Fortnightly mowing is adequate in September and October. Continue into November if the ground is still firm. Even in winter, if there is a dry, mild spell, it is a good idea to ‘top’ the grass. Above all, avoid irregular mowing – it weakens the grass and encourages weeds and moss.
The first mowing in early spring should just be a trim with the blades set high. Gradually lower the blades until the desired height is reached. Do not be tempted to mow very tightly. Very tight mowing weakens the grass unless it is well fed and cared for.
A mowing height of between two and five centimetres is ideal for most Irish lawns – the second lowest and second highest setting on most mowers. The higher level is ideal for rougher lawns and those getting a lot of wear. The lower level is suitable for good quality lawns. The desired height of cut should be maintained when weekly mowing starts.
Raise the blades during drought spells, and towards the end of the season. Any winter ‘topping’ should be done at the highest setting.
The grass-box, or grass-bag, should always be used, unless a mulching mower is used. Mowing is easier, faster and safer, and weed control is improved by collecting seed heads instead of spreading them.
Mulching mowers give good results with dry grass but the mower model should be dual purpose – capable of carrying a grass bag for use when the grass is damp, which is likely early and late in the season.
The removal of the mown grass from a lawn gradually reduces soil fertility because the nutrients in the removed grass are not recycled. Plant nutrients are also removed by rainfall. Feeding is necessary to replace lost nutrients, to encourage healthy grass growth and to allow the grass to compete with weeds and moss.
Feeding is essential
The first spring feed of the year is the most important because the grass will be hungry and weak after winter. Apply fertiliser in March or April to set it up for the growing season. Use a spring lawn feed, which is specially formulated for lawn grasses.
These fertilisers contain the nutrient nitrogen that the grass badly needs but, also, phosphorus and potash for balanced growth. General fertilisers such as 10:10:20 or 7:6:17 are not really suitable for a lawn, because they do not contain enough nitrogen. But they may be used, especially on light soils that are low in nutrients.
Use fertilisers at the rate recommended on the pack. Do not use more fertiliser than advised, or apply it when the grass is already growing strongly, as it only increases mowing. Apply fertilisers evenly to moist soil when rain is expected, or water them in on small areas. Scorching of the grass can be caused by uneven application, particularly in dry conditions.
Feeding can be repeated at least twice, at two-month intervals, using the specially formulated lawn fertilizers. Sulphate of ammonia (containing nitrogen only) and other agricultural high-nitrogen fertilizers, such as urea and CAN, can also be used if large areas are involved, because they are cheaper.
But there is a greater danger of scorching the grass through over-use of these because these are more concentrated, quick-release fertilizers and they can cause a very sudden burst of vigorous growth, and a lot of mowing!
There are also slow-release fertilisers which release the nutrients slowly over a period of months and this avoids the rush of growth after feeding with the normal fertilisers. These are more expensive than farm fertilisers but less effort in mowing.
Lawns can be fed in autumn as well to supply phosphorus and potash to toughen the grass before winter. Autumn lawn feeds should be applied in September or October.
Sulphate of iron can be used in autumn and winter to toughen grass, give it a good green colour and to reduce mowing the following spring. Apply 300 grams per 100 square metres every 6 to 8 weeks from the end of August to April. Spray it on, diluted in 5 litres of water, or apply it dry mixed with about 20 parts sand. This will control lawn moss too.
Wild flower lawn
In September/October, or March/April, a very good quality lawn should get a top-dressing of fine soil mixed 50:50 with peat. One bucketful per 4 square metres will give the grass new rooting material, and boost growth. It is quite a deal of effort to mix and spread a top-dressing, but very effective. A very good lawn should get this each year, but top-dressing can also be used once-off to boost a thin lawn, especially on poor soil. Some fertiliser and seed can be added to the mixture in the latter case.
The best sowing months are September and April, but grass can be sown in most months, even in winter, if the soil is moist, neither too wet or too dry. If there is a little heat in the soil, the seed will take in a couple of weeks, but it will take much longer in cold weather. In September, wait until a spell of rain has moistened the soil. In April, wait until the ground has dried out after the rainy months.
For very good quality lawns that will get little wear, and full care, use a Number One seed mixture, which contains fine, low-growing grasses. For an average lawn with reasonable wear, and adequate maintenance, use a Number Two mixture. This contains both fine grasses and tough grasses and it is ideal for most gardens.
A Number Three mixture contains tough, hard-wearing, vigorous grasses. It is suitable for heavy wear situations, but remember that if it does not get heavy wear it will need more cutting. Buy enough seed to sow about 20 grams per square metre. Grass seed is relatively cheap and it is best to achieve a good dense sward from the start.
Choose a still day after a few fine days when the soil is moist but not wet. Rake the soil. Scatter seed in two directions to get an even spread. Using a yard brush, or rake, gently cover the seed with soil.
If there is no rain for a week or so, and the soil has dried out before the seed sprouts, water the soil with a fine sprinkler. Coarse spray droplets wash the seed away – give a single heavy soaking rather than several light ones.
Hig quality lawn
When the grass reaches 7 to 8 centimetres, it should get its first cut. This is just a trim to encourage the young plants to thicken up. Set the mower high. Do not cut too tightly because it weakens the new grass. There will be no need for rolling if the ground has been firmed and allowed to settle before sowing.
Some soft weeds may appear with the new grass, but there is no cause for alarm because the mower will soon control them. These are usually annual weeds of cultivated ground such as groundsel, fumitory and chickweed. They have no storage roots and soon die out under mowing. If ground preparation has been thorough, there will be no perennial weeds at this stage. Mow the new lawn each week through its first growing season.
The key to success in laying a lawn is careful soil preparation. If soil conditions vary a lot, the lawn will not be uniform, therefore, take some time over soil preparation. Prepare for spring sowing during the previous autumn and winter, and for autumn sowing during the summer.
Lawn meets garden woodland
A weed-free start is essential. Use Tumbleweed or Roundup to control existing grasses and weeds, including perennial weeds. If the weed cover is heavy, a second application might be needed. Level the surface after the initial weedkiller application. Then wait four to six weeks and spray again. Rake the surface and wait again before applying another spray of Roundup or Tumbleweed.
Waiting and repeat spraying is known as the ‘stale seed bed’ technique and it is a way of getting rid of wild grasses and weed seeds that are in the top few centimetres of soil. It is not essential to go to these lengths in preparation but this approach ensures a clean start for the lawn grasses and avoids contamination with wild grasses. While it is possible to control broad-leaved weeds after sowing, there is no easy way of controlling wild grasses.
Large stones, old tree roots and other rubbish should be removed. Level the humps and fill in the hollows before cultivating or adding extra top-soil. This helps to ensure an even depth of good top-soil. Dig the ground with a spade or use a rotavator if the area is large. Allow the soil settle for at least eight weeks to avoid settling later when bumps and hollows will form. Rake over the area when it has settled and move soil around to fill hollows. The ‘stale seedbed’ technique allows the time for settling to take place ove a large area.
On small areas, it is possible to tread the area when dry to firm the soil and break up lumps. Rake over the area to even out small bumps and hollows. Work in some moss peat at the rate of one giant bale per 13–18 square metres. Work this into the top 5 centimetres during subsequent raking. The peat will give body to sandy soils and help to open the surface of heavy soils.
Continue to rake the ground at intervals of three weeks or so. Suspend operations during the months when the soil is wet. Serious compaction can result from walking over wet soil. Repeated raking levels the ground, settles it, makes it fine and controls small weed seedlings. If a flush of weed seedlings gets a start, use Weedol or Basta to burn them off before they get too big.
Apply general fertiliser at 100 grams per square metres about a fortnight before sowing is planned and rake it in. At that stage, stones more than 2 centimetres across should have been removed the top 2-3 centimetres of soil. These can cause problems with lawn-mowing later and the ground should be raked over until they are removed.
A lawn needs at least 15 centimetres of good top-soil. If the quality of the soil is poor, or if there is not enough of it, the grass will always struggle in competition from moss and weeds. Grass will grow on any soil but if the soil is clayey and heavy, growth will be slow in spring and moss will have an advantage. If it is sandy, the lawn will dry out in summer and clover will be a problem.
Lawn – the perfect soil for flowers and shrubs
Heavy ground should have good drainage and land drains may need to be laid before laying a lawn. Drainage should be adequate to ensure that water does not stand in pools for longer than one day at a time after heavy rain. A soggy lawn will be more difficult to mow during wet weather and will not be accessible for long periods.
In a new house garden, check that the soil has not been compacted below the surface layer. Dig a few test holes to see if the subsoil is hard and compacted. If the soil is compacted, it will be necessary to dig through the compacted layer to uncompacted subsoil below to allow rainwater to drain away. Land drains may also be necessary to aid this process.
If there is not enough soil depth, additional top-soil is well worth getting. Purchased top-soil should be checked on-site at source, before it is loaded, to confirm its suitability. Do not accept poor quality soil, heavy soil, or soil with a lot of large stones and hard clods. Also check the load before it is off-loaded to make sure it is the same as promised.
The ideal site for a lawn is a reasonably level piece of ground that gets full sunshine. A slight slope will not matter – except that it requires more effort to mow – but steep slopes can be very difficult to mow. If there is a slope with a fall of greater than 1-in-3, put in a retaining wall and a terrace, or plant the slope with suitable plants.
An open lawn surrounded by mixed borders
Consider the lawn as a distinctly separate area of the garden, bordered by borders, flower beds, pathways and paved areas – an area of the ground surface of the garden, not a general surface into which these other ground surface treatments are placed.
The lawn should not generally contain other features except perhaps for one or two specimen trees or shrubs, or island beds in a large lawn. Otherwise the impression of space is lost.
Choose a favourable area for the lawn and use trees, shrubs, flowers or paving as appropriate for the rest of the garden. The lawn will look better and will be easier to keep. Choose the lawn area for as much sun as possible.
Lawns in the shade of trees, tall hedges and buildings take longer to dry out and tend to be moss-infested. Near hedges and under trees, they suffer from drought in summer as well. In the shade of trees, use ground-cover shrubs or herbaceous plants instead.