Grass Cuttings under trees

[chrisgilltreesurgery]

Hi can anyone help, I know you should not put fresh grass cuttings at the base of trees but can anyone tell me in some detail why

 

Thanks all

 

Chris Gill

[showoffsummer]

Hi I no why but not in much detail and I would like someone experienced to clarify as I'm only 98% sure.

But it's because grass clippings are high in nitrogen and as theymarent living when decomposing the tree will absorb the nitrogen as well as all other nutrients from the grass ending with excess nitrogen in the trees system.

 

I no it's not the best worded and I'm not 100% it's all factual, but I hope it helps.

 

Cheers ciaran glyde

[nepia]

Could it not be more to do with nitrogen robbery whereby nitrogen in the soil is used up in the decomposition of the grass instead of going to the tree, notwithstanding that in the long run more nitrogen goes back into the system once the grass is rotted?

Nitrogen robbery is generally the reason for not putting fresh material mulches down in the growing season so I believe.

[showoffsummer]

Could it not be more to do with nitrogen robbery whereby nitrogen in the soil is used up in the decomposition of the grass instead of going to the tree, notwithstanding that in the long run more nitrogen goes back into the system once the grass is rotted?

Nitrogen robbery is generally the reason for not putting fresh material mulches down in the growing season so I believe.

 

Yes that's the one! Don't listen to me anyone!

 

Cheers ciaran glyde

[MattyF]

I think in some cases it can do not do that much harm as it's acting as a mulch and retaining water and supressing weed growth around the base of tree especially younger trees, yes it will steal nitrogen breaking down but in weather like this any sort of mulch is better than none!

[chilli]

Does the same apply therefore to fresh woodchip?

My son has just started working in the grounds of a National Trust property. The head gardener told him that where they put fresh woodchip under shrubs as a mulch, the shrubs do not do so well that season but are improved in following years.

[log supplier]

Hi can anyone help, I know you should not put fresh grass cuttings at the base of trees but can anyone tell me in some detail why

 

Thanks all

 

Chris Gill

 

chris this is from the web mate

it all depends on how thick you put it down and its state of composition. fresh clippings put on to thick will start to compost producing very high temperatures which can cook the root systems, especially of young plants. again to thick and it can clump together preventing water getting through and also starve the roots of oxygen. the best mulch is an already composted mixture of coarse and fine materials no more than 10cm thick spreading from 20cm out from the trunk to the drip line of the canopy. it helps insulate the roots from cold and hot temps and prevents exsesive evaporation as well as keeps back weeds and grass. if all your trying to do is dispose of excess clippings then your probably putting as much around each tree as you can and id avoid it. if you really want to improve the health of the trees then a proper composted mulch is a far better option and if you talk to your customers about this there could definately be an extra earner there for you to.

[nepia]

Does the same apply therefore to fresh woodchip?

 

Yes: the decomposition of the wood in year 1 takes the nitrogen from the soil but by year 2 the decomposing's done and that nitrogen - and more - goes back.

[janey]

Does the same apply therefore to fresh woodchip?

.

 

I was always taught that you shouldn't use any sort of fresh, uncomposted vegetable matter as a mulch as it can "rob" the soil of nitrogen.

 

However, if Glyn Percival et al now say that it's perfectly ok to use such mulches, then I'll go along with them.

[Mesterh]

I was always taught that you shouldn't use any sort of fresh, uncomposted vegetable matter as a mulch as it can "rob" the soil of nitrogen.

 

Thats what I was taught.

 

Although it was more of a problem with delicate plants.