Repairing conifer soil damage

Garden noob

We moved into our house last Christmas. The garden is north facing with 50' of lawn and had large conifer trees along the west fence (six in total, approx 8-10 m tall), so the garden received next to no direct sunlight. I've chopped down the trees, scarified extensively, reseeded and overseeded with grass seed and now the lawn is starting to come together. However, the soil is noticeably poorer at the bottom half of the lawn that's nearer the old conifer trees. It's dry and crumbly and has far fewer worms. Consequently (coincidentally?) the grass grows much slower here and is less lush. There are conifer roots just below the surface of the lawn although the stumps are dead. I assume the conifers have stripped the soil of nutrients over many many years. I don't want to rip up the lawn to nourish the soil, can I add anything to the lawn to improve soil quality? Does it require repeated applications over many years? I read about adding a thin layer of peat moss but am concerned about the ecological impact. I should stress that I'm concerned about the soil quality rather than the growth of the grass. I can add chemical fertilisers if I'm that bothered about the grass, but I really want to address the underlying issue. I look forward to hearing your thoughts.

Woodgreen wonderboy

Autumn lawn feed concentrates on encouraging root growth. Suggest you give it a feed now and again next spring and autumn. Don't use summer fertiliser for a couple of years or until you think the grass is back growing normally. Also spread some multi purpose potting compost or some such , new or spent, after you have fertilised. Just a thin layer, and inch or so will do. Fork it to improve drainage and to encourage some MPC to go down below the surface.  Brush MPC down the holes. Do this each time you fertilise to gradually build up the quality of the soil.Your grass should start growing more strongly. You could mix in some grass seed suitable for shade/ hard wearing conditions. Don't let it dry out in hot/dry spells.( not sure if it ever a good idea to add moss to your grass)

I have a similar problem area under some ash trees... above treatment has helped improve it greatly.

Garden noob

Thanks for the input! It's confirmed some of my thoughts but added much needed clarity.



I've recently spread bone meal as that has a high phosphorus rating (for roots) and is slow release, shall I add add more in the Spring? Or is there something better to spread? The options are overwhelming!

Woodgreen wonderboy

I haven't used bonemeal, just Autumn lawn feed which should also kill off any moss problems. Bob Flowerdew once said on GQT that he always uses Autumn feed in spring because if you build up strong roots the rest will follow.

BM should have the same beneficial effect, suggest you use either 2 times a year minimum, with perhaps an added dose in mid summer when conditions permit, i.e. not too hot and dry. Add a little MPC to balance out the chemicals, the build up of which might prove a little harsh.

I think this regime can only benefit your grass.

Dovefromabove

We had a similar lawn when we moved here 3 years ago (large ash trees at the end of the garden).  As well as scarifying, aerating and brushing in some compost as WW has described above, we've given a feed of  seaweed plant food http://www.marshalls-seeds.co.uk/seaweed-enhanced-plant-growth-stimulant-pid5030.html?gclid=CKvW3Z6h0sECFQoUwwodhTIAjA&gclsrc=aw.ds in the spring and again in mid summer, and watered it in well.  We chose to use this rather than proprietary lawn feeds as we have lots of wildlife (including frogs, toads, hedgehogs, grass snakes etc) and didn't want to use anything that could affect them.  With regular mowing and continuing to scarify and aerate twice a year, the lawn has improved immeasurably.

 

 

Garden noob

Just following up this thread in case anyone is interested. I ended up spreading a thin layer of compost as suggested (probably nearer 1 cm) which helped a bit. The thing that seemed to make a big difference though was a few generous applications of pelleted chicken manure. It's supposed to encourage worm activity and it definitely helps the grass grow and make it lush. I like the fact that it is slow release (low maintenance) and it seems to have helped the soil. Tubs in Wickes were only ??5, compared with ??15 in homebase etc

Garden noob

I had a bit of fox activity in my garden but if anything I think it's decreased in the few months since the chicken manure went down (although I'm sure that's purely coincidence). So thankfully foxes haven't been a problem. Re it being high in nitrogen, that's why I gave it a go, but I was pleasantly surprised that it seemed much more effective than the chemical fertilisers I've used in the past - the lawn had a new lease of life. And unlike chemical fertilisers it doesn't need frequent applications. The only downside is that even though the last application was early Aug, it's now nearly December and my lawn still needs regular mowing!

Steve 309

It'll slow down when the weather gets cold.

The other advantage of chicken manure over inorganic fertiliser is that it doesn't take oil energy to manufacture/extract.  Or produce toxic by-products.  Or wash out and cause eutrophication in the local river. (or provide employment...)

Glad it's working anyway