Talkback: Green manure

This year i am going to take on a member of the families garden who has recently past away would it harm if i did not use green manurs ?

Hi Kate i've just sown some field beans as a green manure, but when should i dig them in- should i let them flower first? Jenny

Hi Kate, Our garden contains reddish dry sandy soil containing stones, and is difficult to dig, also on a hill. Next spring I'd like to grow fruit and veg on the site. Could you suggest the best way to improve the soil please? Would you use green manure in this case? Thanks Hannah

I would like to sow green manure on my allotment but as I am constantly battling with bindweed I don't see how I could dig it in in the spring. Any suggestions?

Jenny - technically you should dig in the plants before they flower, as they use energy to produce flowers, which would otherwise be dug back into the soil to feed your next crop. But I always let a few flower - especially clover. Cut the foliage down two-three weeks before you want to use the bed. I would leave the roots in the soil so their nitrogen-fixing nodules can feed your plants. Follow with a nitrogen-hungry crop, such as brassicas. Hannah - you'd probably be better off adding home-made compost and well-rotted horse manure. This will help bind the soil's particles together, making it more water retentive and rich in humus. Is it difficult to dig because it's stony/rocky, or is it compacted? If you add manure/compost now cover it with plastic sheeting to prevent the nutrients leaching from the soil. You shouldn't need to dig it in - worms will do that job for you. Regarding the stones, remove them by hand or sieving if you intend to grow root veg such as carrots and parsnips, but they shouldn't be too troublesome if you're just planting a few fruit trees. Ann - probably best to deal with the bindweed first, then sow a green manure afterwards. Now's a good time to deal with bindweed as its growth will be slowed until spring. A green manure will suppress weed growth to an extent, so if you dig the patch over and remove every tiny piece of bindweed root, and then sow a green manure over it, you might be lucky. Kate

We have a 50 metre band of a double row of trees around our garden, we've been keeping the entire area free of weeds and grass but this leaves the clay exposed, would you recommend a green manure for this/something else, or would the roots of the trees themselves hang on to the nutrients? It wouldn't really be practical for us to dig it in as it's approx 50m x 2m. Also we don't want something that would self seed in the lawn, although we wouldn't mind as long as it's growth rate didn't exceed that of the grass...i.e. unlike daisies etc which result in grass being mowed more regularly than needed. Thanks!

I really must object to Marie Counter's email. Leave James Sinclair-Alexander's words alone, it's the high spot of the month and I read the comments to my partner!

I am new to gardening and I would like if possible an easy solution of improving my garden soil without the backbreaking. It's heavy soil waterlogged after heay rain, dry in summer, I can't grow much in it and its very dificult to work with.

After reading the blogs about green manure I have decided to sow Field Beans. The question I have is how thick should I sow the seeds?

I have just watched Monty's video about sowing green manure and he answered my question. However now I have decided to sow Grazing Rye because our soil is clayey.

Hi Kate, Two years ago I made the mistake of having turf laid onto the existing soil in our new build house in County Durham. I have since learnt that the soil is mostly heavy clay and generally awful for lawns. I have also learnt that the soil was not rotavated as promised and my wife and I are pulling all kinds of rubbish out of the soil which the builders couldn't be bothered to remove. I read somewhere that if you really want a beautiful lawn, you need to put down up to 30cm of high quality top soil. Obviously this will be very expensive and excavating 80 square metres of heavy clay soil to the depth of 30cm will be a heck of a job. I have just read that you can improve heavy clay soil by rotavating it and mixing in sharp sand, gypsum and green manure. Is this correct? and if so, do have any idea of how much of each i would need for an 80m2 lawn?

Hello. I am a new gardener and would very much appreciate your comments please. I have large bedding boxes made from sleepers around the garden which I would like to start planting in Spring. The soil is clumpy with clay & stones. I have just de-weeded the boxes and turned over the soil and not sure of the best next options. Would you advise for me to use grazing rye now or would I be better buying compost from a local company (please advise what would be the best compost to purchase) to help the soil for spring planting? Thank you in advance.

can you help out there i love baked potatos and would like to try and grow some but which seed potato wood i need to buy

Elizabeth - is there a reason why you have not let grass grow beneath the trees? Is it like an orchard? You could try growing comfrey, though if the area is shady it might not do so well. The variety 'Bocking 14' does not self seed, so won't seed into your lawn, but it will bulk up and spread eventually through its roots. Comfrey is great for bees and rich in potash and other minerals. Once a year you could chop down the foliage and leave it to rot into the soil to fertilise the trees, or make a comfrey solution to feed to flowering plants and tomato/chilli/aubergine crops to improve flowering potential and fruit set. Gill - it sounds like you have heavy clay soil. I'm afraid it's going to be backbreaking! Just dig over a small patch at a time, incoporating as much organic matter (in the form of home-made compost or well-rotted horse manure) as you can get your hands on. Grow deep-rooted plants such as potatoes, which will help to break up the soil. A deep-rooted green manure such as grazing rye will also help. Here is more information on improving soil and sowing grazing rye: http://www.gardenersworld.com/how-to/projects/soil-improve/ http://www.gardenersworld.com/how-to/projects/soil-improve-green-manure/ Des Caldwell - That sounds terrible! Yes, you can improve heavy clay soil in the manner you suggested, but if the builders didn't do a very good job initially, it may be that you actually have a lot of subsoil in the mix, which is very low in nutrients and not suitable for growing things in. Is the lawn not growing well? You could try working with what you've got: aerating, scarifying and feeding your lawn (info here: http://www.gardenersworld.com/how-to/projects/category/lawn-care/), and perhaps sprinkling a mixture of sharp sand, topsoil and grass seed over the lawn. This will probably need doing every year if you want to improve the state of the lawn in the long term, but its success depends on how bad it is now... Melanie - I would sow field beans now, if you are in the south of the UK you might get away with grazing rye, but field beans can be sown until November. They also have deep roots, which are excellent for breaking up heavy soil. You could mulch with a combination of compost or well-rotted manure, which would help aerate the soil and separate its heavy particles, but I'd personally opt for sowing a green manure now (easier), then grow potatoes next year. These will continue to break up the soil and should make it more manageable in the future. You could follow the potato crop with a mulch of compost or horse manure in late summer, or just sow another green manure and leave it til the following spring. June - there are so many vareities to choose from. here is a list from allotment.org.uk: http://www.allotment.org.uk/vegetable/potato/potato-flavour-type.php Kate

Kate - thanks so much for your advice, they're just regular trees/non-fruit but it was so difficult trying to cut grass around them we've completely removed it, also we figured the less grass the more nutrients would be available to the trees. There is part shade in some areas as the trees are still relatively young, but I wouldn't mind trying your idea, even in a test patch for starters and then take it from there, thanks again!

Thanks everso for the advice on my heavy soil, whilst the weather if still tolerable I have set to work a little bit at a time turning and digging as I go. It's far from easy but I have realy enjoyed the hard work and sense of achievment. I can't wait to get planting the green stuff to improve what at the moment is just mud. Hopefully by the spring i will have more choice as to what I can plant.

Hi again,will using grazing rye work in the flower beds, the soil there is just as bad. Heavy soil waterlogged after rain dry in summer. Im not sure where to begin. Can i still sow the seeds now, I live in the North West of England

We haven't used green manure before and are interested in sowing it on our allotment as we have added only a little manure in the last 4 years. We are in the North of England. What do you recommend?

Thank you for the picture of not leaving soil bare. around our allotments are huge swaths of bar turned earth throughout the winter. I am told it is good to let the frosts get into the soil to kill off pests. Is this so? My other question is about field beans. The mice seem to like them so they only come up in patches. Any organic and humane solutions to that? Also what should follow field beans and what should thy be following for the best results? thanks.

kate, after having an extention done on the back of my house, the builder made a mess of my then lawn by mixing plaster and throwing the water and left over plaster on to it. Eventually I had a new lawn laid and the gardener seemed to have done a good job at the time, it grew qickly and we mowed it at the time he told us to do so but it didn't seem to grow very thick and I found I had to spread grass seeds to thicken it up. Two years on the grass still is not thick and lush I have done everything the txt book says to do and my lawn is no better. If I leave it to grow it appears to be thickening up but as soon as I mow it,you can see the soil, once you walk on it a liitle, it is a muddy mess again. Before the gardener laid the grass I was surprised that he didn't flatten the soil down, he levelled it and thats all, the only time it can be walked on without the mud sticking to your feet is when we have a drought and that's not that often in Manchester. Please help I have family coming to stay from Australia & Newzealand it would be great to be out doors weather permitting and using the old BBQ