How to repair a damaged garden lawn

There are three things a healthy lawn needs: Sunlight, Water, and Oxygen.

Repairing a damaged garden lawn sounds simple, however nature regularly introduces new obstacles to achieving the perfect lawn so it requires regular work.

You may notice it is extremely soggy after a rainfall, or extremely hard when there is no rain. Watering during dry periods will hide the issues for a while, but your lawn should be on a regular maintenance schedule just like any other living thing needs to be. Applying a 4 in 1 mixture to kill off moss and weeds every spring will help hold off some issues for awhile, however that is treating the symptoms versus dealing with the problems.

Not all issues are on the ground. Make sure you look up too as it may be a tree is above you. What type of tree it is makes a difference. Deciduous trees block sunlight and drink a lot of water as well as dropping their leaves in the autumn leading to thatch build up if not raked up. Coniferous trees drop their needles, which are acidic, and change the soil composition when the needles sit on the ground. Walk through a forest and take a good look at the big bare circle under a coniferous tree as almost nothing can grow in that acidic soil mixture caused by those needles. You will find it very difficult to grow grass anywhere under or near a coniferous tree and even if you cut down the tree you will need to gradually change the soil composition where the needles used to be. Get professionals in if this is the issue you are dealing with, both for the tree removal, and the lawn preparation.

Here is how I take care of my lawn. This short list of lawn care techniques were picked up over the 15 years I spent working on golf courses where the quality of our lawns was make or break for our business.

Scarify to remove debris from a lawn

This is the process of removing debris from a lawn. Leaves, dead grass clippings, and dead moss can build up on your lawn. This layer prevents the water and oxygen from getting through to the roots of your grass.

This can be done with a machine which has small thin blades which cut through the thatch, which is the debris build up, and ideally collects it. Your lawn will look awful immediately after a scarification, but it will come back much stronger in a couple weeks. Don’t do it the day before a garden party! You can buy these machines, search for a Lawn Scarifier with a collector bin. You can also hire more robust scarifiers.

This can also be done with a scarifier rake. The incisions won’t be as deep as a machine, however it is a more cost effective way to do it. I picked up a scarifier rake from my local garden centre for £40.00.

Time Required: 90-120 minutes for a lawn between 50-75 SqMs with a machine

Frequency: twice per year (spring and autumn)

Aerate to reduce soil compaction and improve oxygen to root systems

This is completely different from Scarifying. Unfortunately when you google lawn aeration you often get scarifiers as the search results and it is not the same thing. Aerating is the process of using small steel tines (10mm to 20mm steel tines) which punch holes into the lawn. This breaks up soil compaction, softening the lawn, and allows water and oxygen to easily flow through the lawn improving root systems and water drainage.

This is best done with a machine, which can be hired in. Purchasing lawn aerators is extremely expensive so unless you plan to use it every few weeks, which you should not do, hire one in. If using a machine you have the option of solid tines or hollow tines. If you are doing this manually your only option is solid tines.

Hollow tine aeration: There is no really good reason not to use hollow tines if hiring in a machine. Hollow tines actually remove small tubes of soil, or cores, which can then be rakes up. If using hollow tines I do recommend topdressing at the same time.

Solid tine aeration: This is, as it sounds, a row of solid spikes which you poke into the ground. You can hire a machine for this or there are manual systems such as spikes on shoes, rows of spikes attached to a long handle, and some more advanced hand held aerators. I personally stay away from the shoe-version, however note any aeration is better than no aeration.

There is one additional method of aeration which is ideal for rocky areas which I have not mentioned, this is hydro-aeration. This is the process of firing water jets into the soil to break up compaction. The advantage of hydro aeration is the extremely rapid recovery time of the grass, which is generally just a few days. It is not very popular as hiring in the equipment and operators is an expensive process and there are a limited number of companies which do this type of work, almost none which work regularly with residential customers.

Time Required: 8 Hours for 1 person for a lawn between 50-75 SqMs with a machine (half to aerate the lawn, half to clean up the area)

Frequency: once per year, in spring, is enough for a residential garden

Topdress to level your lawn and improve soil conditions

This is the process of adding a thin layer of sand and or a sand/loam mix over the surface of your lawn. This is the most effective way to kill moss. Other benefits of topdressing is that is helps level your lawn as the sand will naturally fill in small pockets which have been created over the years. It also helps break up clay.

I strongly recommend topdressing after aerating, this is how it is done at golf courses. Use horticultural sand and a soft rake or, use a firm smooth edge, like the flat back side of a lawnscaping rake. Just brush the mixture around the soil ensure you are applying it evenly. Once you are done spreading it as evenly as you can with the back of a rake, go over it again with a broom.

Do not apply more than 0.5 to 1m3 of top-dressing for every 100 square metres. The sand will disappear after two weeks time.

Time Required: 8 Hours for 2 people for a lawn between 50-75 SqMs (one person levelling the sand, one person moving the sand from curb side to the garden)

Frequency: once per year is generally sufficient

Overseed to repair patches and blend optimal lawn species in

This is the process of adding additional seed to your lawn.

If you use a lawn fertilizer, weed and moss killer treatment such as a 4 in 1, wait 4 weeks after applying that to overseed your lawn.

Cut your lawn to approximately 25mm. The temperature needs to be about 13 degrees celsius for overseeding to germinate, and will take 7-21 days in that temperature, to grow. Keep the seeds wet during this period, water in the morning and early afternoon.

Time Required: 2 Hours for a lawn between 50-75 SqMs

Frequency: once or twice per year

Garden Lawn Patch Repairs

For small bad patches of bare earth or rock hard sections that look like the surface of the moon, I recommend doing patch repairs. This is a good quick fix if most of the lawn is looking tip top.

Break up the lawn in the area, fully dig out any weeds or whatever it is which is growing in the area which is not grass. Often you will find one large weed has grown with wide leaves which have grown above the grass, killed the lawn in the surrounding area by stealing all the water and blocking the sunlight to the grass shoots. Dig the weed stems out fully, don’t just rip off the top (basically don’t be lazy).

Dig down to a depth of 30-40mm, remove the earth, there may be more weeds, rocks, toy cars, buried treasure, or large roots under the area you couldn’t see from the surface.

Most areas in the UK have fairly healthy soil conditions and a mix of 50% topsoil and 50% loam will be ideal. In some areas of heavy clay, such as where I live, I use 50% horticultural sand and 50% topsoil instead. Mix these in a small bucket with a hand rake. Once this is fully mixed, add in a suitable lawn seed into the mix for the sunlight conditions the area receives. Do these very gently, you do not want to break the seeds.

Now go around your garden and fill in all the potholes you created. Tamp down the areas gently. You want these potholes to be slightly proud of the ground around them as because you disturbed the ground it will compact back down again.

Water the patch daily, the best time is in the morning and the best way to do it is with a watering can or a very very light setting on a garden hose nozzle, you do not want to spray these areas with any pressure. Do not walk on the areas for 3-4 weeks. You should see the first shoots of grass in 7-14 days provided it is over 13 degrees celsius.

Horticultural Sand and Seeds, Scarifying Rakes, a 4 Prong Aerating Tool are all available from your local gardening centre. This work doesn’t need to be expensive.

In terms of what order to do the above,  If you apply a Spring 4 in 1 mixture of Fertilizer, Weed & Moss killer, you need to wait 4 weeks afterwards. Then Scarify, Aerate, Topdress then wait 2-3 weeks and overseed. Wait 3 weeks and from there onwards do Patch Repairs

It is very rewarding seeing the results, especially those first few shoots of grass. Remember to be patient and you won’t be damaging anything permanently, if if it doesn’t grow try to identify the reason why (sunlight, water, oxygen, ground temperature and soil composition are the usual reasons) you can do it all again.

Gardening requires patience, you will not change your lawn overnight and almost everything you do from the above list will take 2-3 weeks to see visible results.

Happy gardening folks, and remember if it all goes south in your garden and all the grass dies and you are down to bare earth, you don’t have to hire a turf cutter anymore as there is no turf to cut! You can just go straight to the rotivator phase of preparing the area for fresh lawn turf or seeding.

Please get in touch if you have any questions. Remember that not all of this advice will assist all gardens.

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