Creating and Maintaining a Lawn
Creating and maintaining a lawn
Given careful preparation, a high quality lawn can be maintained by following a regular routine of simple tasks. It can be a distressing sight to watch a lawn unnecessarily deteriorate into a patchwork of dull greens, yellows and browns. Unfortunately, this situation is commonplace and so it is the aim of this section to outline simple rules for successful lawn establishment.
Seed Bed Preparation
The key to producing a high quality lawn lies in site preparation. The first operation is to clear any waste material such as bricks and waste timber, either by hand or machine. If the site is already overgrown then a total non-residual herbicide should be applied, making sure that pernicious weeds such as docks are controlled. Repeat spraying may be necessary for complete success. If re-contouring of the site is required it is important to remove the topsoil and store it to one side, being careful not to contaminate the topsoil with subsoil. Once clear of the topsoil, the subsoil can then be contoured to achieve the required levels. At this stage any drainage work should be carried out. In order to prevent severe compaction of the subsoil the use of heavy machinery should be avoided in wet weather.
Having achieved the required levels the topsoil should be replaced to a depth of at least 100mm. If the topsoil has a high clay content then horticultural grade sand should be incorporated to aid drainage and air movement. If the soil is excessively sandy and free draining, peat should be worked in to ameliorate these conditions. Once thoroughly mixed the final levels are achieved by alternate hand-raking and heeling. This creates an even surface. Ideally a slow-release fertiliser such as GSR Tri-Phase 18-3.5-8 applied at 35g/m2 should be raked into the topsoil prior to sowing the seed.
Sowing a Lawn
Sow the seed
The importance of sowing at the correct depth cannot be overstated. The correct sowing depth is a depth at which the seed has good contact with the soil and is closely surrounded by soil so that it is consistently moist and warm and has a good anchorage once germination has occurred, for most lawn seed mixtures this is approx 10mm If sown too deep you are making the plant work too hard to make it to the surface and it will either never make it or be a weaker plant once it does. If the seed is left on the surface it can germinate but there is a greater chance it will dry out, or get too cold and when it does germinate then for the first few days it will literally only be anchored in to the soil by the newly emerged radicle (a single young root), and will be susceptible to being broken off. Too much sunlight can also have an inhibiting effect on the germination of seeds.
Spreading the seed
Seed can be broadcast by hand or by using a spreader that you can buy or hire. You will be able to set your spreader to the required seed rate. A useful tip to get even distribution using a spreader is to split the sowing rate in two and sow in two directions. I.e if the sowing rate is 50g/m2 then sow horizontally across your area at 25g/m2 and then diagonally at 25g/m2. If sowing by hand across a large area then work out how much seed you need for the whole area and then split the seed into four, then divide the area into four (use string or lines of sand). Then sow a quarter of the seed onto each area. This approach prevents you from getting half way across a large area and realising you are running out of seed.
Rake the area lightly until the majority of seed is covered with soil, then lightly tread or roll the area to firm the soil around the seeds. If you can see a few seeds on the surface afterwards but most have gone then that is correct. Don’t worry about the odd seed on the surface.
Water the seedbed
If the area is of a manageable size and you have access to irrigation then watering little and often while the seed is germinating is the correct approach. As a general rules of thumb you should water until just some particles of soil stick to your hand when you press your palm into it. You do not want to see pools of water laying on the surface and you do not want a hand covered in mud. If the area is too large to irrigate or you do not have access to irrigation then don’t worry. Nature will take its course especially if sown in April, May or September when traditionally you should get some rain. If you sow seed and it does not rain, seed is resilient, it will remain in the soil and wait for rain. I.e you sow a lawn on 1st June and we have the driest June on record, it gets no water. It won’t germinate, but if it rains hard in the first week in July it will germinate and you will see new shoots with 14 -21 days. The lawn has taken 14 -21 days to germinate, it was not slow to germinate it just didn’t get any moisture for four weeks.
Get your timing right
An increase in the soil temperature increases the speed. As a general rule of thumb the best months to sow grass seed mixtures in the UK are April, May, June, late August and September. July and August are fine with regards to soil temperature but can be dry months; that said if you have irrigation, or are happy to wait for rain then July and August can be good months to sow seed. Once rain falls, germination can be very rapid indeed and let’s face it we live in the UK, it could rain anytime and frequently does.
This should be assessed on the height of the seedlings rather than any fixed length of time. Wait until the seedling are approximately 50mm in height and then lightly firm the soil by either penguin walking across the area or preferably by using a light roller or the roller on a lawn mower if yours has one. The idea of firming the soil is to ensure the new seedlings have a firm anchorage so that the first cut does not tug them out of the ground. This is also when your correct seed bed preparation and sowing depth pay dividends. The idea is to lightly firm the area not compact it so don’t be tempted to over do it, one pass of any of the above methods will suffice. Wait a day or two and mow the new lawn down by about one third - so if the plants are at 50mm set you mower at 35mm. If you have let the plants grow longer, then set the mow at an appropriately higher height to achieve a trim of about one third of the plants. If you don’t have mower that you can set by height then set it at the highest height mow a small patch and assess if you think it is correct. If in doubt then go lightly for the first cut if you only take one quarter rather than one third that is better than lopping the plants down and stressing them.
Gradually reduce your height of cut down to the required height over a period of weeks. If you have sown in the autumn then you may only get to cut the lawn a few times before it is time to stop for the winter.
You can begin to use the lawn after the first cut but heavy use should be avoided in the first year, especially if sown in the spring. Lawns sown in the Autumn that have established should tolerate more use the following summer.
With an autumn sown lawn/grassed area then the fertiliser applied at the time of sowing should be enough to see the lawn into winter.
With a spring sown lawn then the pre -seed fertiliser will last up to four weeks if you used a quick release fertiliser such as G1 Quick Start or 12 weeks if you used a slow release such as GSR Tri-Phase after which time a new feed should be applied. We would always recommend a slow release fertiliser because:
- They feed the grass consistently and uniformly over a twelve week period.
- They avoid large flushes of growth followed by gluts between feeds.
- They reduce the leaching of nitrogen in soil water and consequently into water systems.
- Even though the cost is more per bag you apply them at half the rate because they are more efficient and therefore often work out as more cost effective.
Recommended fertiliser plans for a domestic lawn
|Mid March||Novatec Premium||35g/m2|
|Mid June||GSR Tri-Phase||35g/m2|
|Early – Mid September||Novatec Premium||35g/m2|
Choosing The Seed Mixture
The correct seed mixture for the lawn will depend on the user’s situation. If a high grade ornamental lawn is required then fine grasses should be chosen, such as Luxury lawn, but it must be realised that such a mixture will require careful maintenance. If the lawn has to withstand heavier wear, a mixture containing ryegrass should be considered, such as Family Lawn.
To produce a high quality lawn, many prefer the cylinder type mowing machine. This cuts by a scissor-type action and leaves a first class striped finish. It is also preferred once the lawn is established to remove clippings. This will reduce the amount of dead material and keep the number of weeds and worms to a minimum. However, it is important that this type of machine be correctly adjusted and checked, preferably before each cut, otherwise an uneven sward will result. To obtain best results the lawn needs to be cut at least once, possibly twice a week in the growing season. A good height to maintain a grass sward is 15mm, but this can be closer depending on the desired result.
Another type of machine commonly used in lawn management is a rotary mower. These machines are more practical on uneven surfaces and domestic lawns. They do however product a less “clean” cut relying on a chopping action.