Can anyone diagnose my lawn? Patchy growth

Hello!

I have a reasonable large lawn (well, grass) maybe 200sqm ish. I'm on very sandy soil. However when the growth comes in, it grows in patches, some very lush, and some barely at all. I use various feeds throughout the year, aerate with a fork and remove any thatch with a spring tine rake (great workout).

The net result is that I have to mow low to make it look any good, meaning that when the summer drought kicks in it costs me a fortune in water to keep it alive.

What I can't understand is why the local parks, which face the same environmental challenges I do, seem to look so much better. All they get is a mow from a tractor every few weeks. I've hated with this for seven years, and with the water bills going up I'm not sure what I'm going to do.

Attached a photo. Would massively appreciate some opinions

 

Could be leatherjackets? Do you have a lot of daddy-long-legs in early summer? Perhaps the birds that would normally forage for them are put off by the treatments.
The only thing that I can suggest is to rake out the patches, sprinkle some topsoil or sterile compost and oversow with fresh seed. Wolf do a nifty range of cultivator-type tools ideal for scratching up small areas. Sarcloir LB-M Wolf-Garten

 

Two thoughts:
Has it been patched; ie could it have differing grass varieties ?
Have you top dressed it with organic material ?

 

We have this and it was because the grass was sown with a mix of grass varieties. Some are more drought tolerant so thrive when the other varieties don't.

 

Grass plants typically need to root the same depth as the height the top grows naturally to flower. Differing varieties therefore will root differently; if they are mown/grazed before they have achieved a flowering height the need to root more deeply is supressed and they reserve their energy .using it to restore the top to maximise carbon storage/energy production by photosynthesis. This is emphasised in times of stress, such as drought because the shallower rooted will not get to water, certainly having a visual effect to the top.
Premature mowing has a detrimental effect in the same way as premature/over grazing.

 

If there are stones/bricks/rubble/other rubbish buried under the soil, or even some sandier or more compacted pockets of soil, that can make the grass growth uneven (like crop marks that archeologists look for to find buried remains of buildings etc). But I think it's more likely different varieties of grass.

 

Thanks for all your very helpful replies

@noisette47, not sure about leather jackets. I don't think we get a lot of daddy long legs. Regarding top dressing, can I use normal 10mm screened bulk soil? I can't get an affordable source of the top dressing mix locally .

@infradig and @Thevictorian I've never top dressed it in the time I've been here. Seven years. May well be different varieties as it's had repair when drought has killed off swathes of grass.

@JennyJB may well be right. As above, it's had lots of repair.

Is it worth having a bash at top dressing anyway?

 

In areas of grass, nature would expect some of the grass to return to the soil by trampling by herbivores. You are removing grass as mowings and also as thatch. You ought to return some humus material to replenish the dark brown area under the grass (above).
The best way to do this is by top dressing with fine humus(composted vegetation, peat, leafmould etc), brush it across the surface and allow worms to drag it down to the root layers.
You can see worm tracks in the section above. Nature will process this material to feed your grass.It also acts as a water mediation to protect the grass from the greater effects of drought.
If you do this perhaps Spring and Autumn each year, like your herd passing through! ;you will grow better grass.

 

@infradig. Thank you. As aside, might it be better if I mowed frequently but left the small clippings on the grass?

I'll have to see what material I can get to top dress. I'm guessing topsoil not good enough?

 

Leaving clippings on the top is not always a good idea as you may be introducing more unwanted weeds into your lawn. Also, it can block out light that helps the grass grow, especially when it's spring time. This technique is often used during drought or in summer time to reduce the need for watering. Your lawn issue is a combination of type of grass seed (not suitable for the climate or soil) and lack of top dressing. But this should also be part of other tasks that should keep your lawn OK if you already scarify and rake your lawn to keep a thatch from building up and crowding out potential lawn growth.

 

Have you dug out a deep sample of soil and compared it to a good growth area? Visually and by soil sampling (lab - best or home kit).
Also animal urine maybe like rabbits. They can hang around certain areas doing their thing.

 

Can I use a premium top soil well graded to top dress? Most of the very expensive top dressing mixes seem extremely sandy, and I can't see that helping my situation at all. My soil _is_ basically sand.

@TattyMac I haven't ill try a dig at the weekend and see what I can see. It's always a losing battle here. My house is built on old dunes from the 1930s!

 

Premium topsoil - sometimes that just means no stones. No reason why you can’t just use only soil (only up to an inch in depth in case you smother existing grass). Just makes the surface more lumpy, hence the sand. But a little soil probably won’t improve things by much, especially if there is only an inch of soil in the first place, and at the moment you don’t know.

You can try lots of things but finding the cause first would best, and then act. You could dig out a tubular sample to see how much soil is there is and maybe compare it with a sample where the grass is good. Can easily reseed the areas afterwards.

Grass needs 4 or 6 inches of topsoil to grow well. If one area is mainly sand then that could be your answer.