The easiest way to great soil (without a wheelbarrow)

And no, it's not 'no dig'

I won’t beat around the nettles; getting straight to it - sow some green manures.

They are not green poo as someone once guessed (no, not me) but plants that you grow, either in bare soil or as a companion crop beneath other plants, to enrich and improve soils.

They usually grow fast and are exceptional at driving roots down to find water and nurtrients whilst either binding or loosening soil structures. Sounds great doesn’t it? And reader, I can confirm after only a year of using them, that they are, and I am convinced.

There is one for pretty much any soil type or problem. They prevent weeds by smothering them, stop soil erosion and keep feeding the soil. They also look pretty and some of them I can’t cut too for flowers!  I’ve also noticed more diversity in pollinators and beneficial insects.

Some can be left in place for several years but I’ve only been trying since last easter so come back next year to find out more.

So far I have used them to feed and keep beds full when waiting for another crop to go in or to underplant - particularly clover with the roses, buckwheat and mustard with dahlias, and earlier this year whilst waiting to see if dahlias did emerge (they did), phacelia across the beds.

If you do some research, traditionally green manures are dug back into the soil to put those nutrients right back in there but I have been pulling ours as I’ve let them mature, and then added them to the compost heap. This is working well for me so far and I’m literally growing material for the compost heap along with nettle's and comfrey. It also means I can turn beds around to plant into quicker. When green manures are dug in, one usually needs to wait 4 weeks before sowing any seed into the soil. I prefer rip, pull, clear and plant method!

They have certainly reduced the weeds where I have used them and I am sure improved the soil. We have very dry sandy soil. The structure does look better; it isn’t quite so dry and its darker in look, rather than pale and crusty like it was this time last year. I haven’t bought in any other mulch since late autumn 2021 when I think the material that I did use caused some issues for me. I’ve bought different potting composts but mulched only with my own compost or sown green manures. So far so good.

I’ve just pulled plants, not worrying too much whether I pull the roots or not (they will continue to feed) and planted in the stubble left.

Green manures are best sown between April and August, with a few happily sown right into November including rye and field beans. I might try some of those this winter. Ideally I would clear beds in late September and get mustard and phacelia in then to over winter since they are particularly good on fine sandy soil. I imagine they could be a bit more difficult on clay soils, and having to clear or dig them. Then and only then would I be relying so much on lots of organic matter over the winter.

You see soil microorganisms need carbohydrates to be active, and therefore feeding fungi and keeping the ‘world wide web’ of the soil exchanging water, nutrients and minerals. If the ‘sweeties’ are not made but a plant growing above the soil, sending sometimes up to 75% of its carbohydrates down, then they become inactive until the moment they receive them. So by having a green manure growing at all times, the soil bacteria, fungi et al is active, worms feeding on rotting vegetation and all sharing working together. I certainly have noticed plants are quick to settle in and I would put that down to the improved activity since growing green manures.

I don’t think I have managed to improve the fertility as much as I’d like yet; on my sandy soil, nutrient is lost quickly and plants are quite small. I am adding a thin layer of homemade compost and I think plants will be better later on in the season now. It takes time to improve fertility so I expect the next few years will show development as we go. I reckon growing winter rye, beans and lupins (all special green manures) will certainly help that.

There are still weeds but certainly less and when I have underplanted, dahlias, roses and eremurus, the flowering has been better than ever. I have hardly watered too. Have they helped that I wonder? Or would my plants be twice as tall if I had.

I sow green manure either as a mix, depending on what and when I am sowing it, or as an individual plant, at a very low rate. It is supposed to be about a gram per square metre but I don’t manage that low! I sprinkle it over the soil, tiffle* it a bit so the seeds are mixed and under the soil then water a little. Best if you sow just before a rain fall. Ideally you take out big weeds and stones too!

I was really convinced about green manures when I heard the Land Gardeners speak. They hardly spread mulch instead using green manures to exclusively feed and cover their soils, using the ‘crop’ as compost material. Their compost is used to grow plants in. Makes so much sense doesn’t it! Green manures are usually the domain of the vegetable grower, but as I maintain, great crops come from growing a great diversity of different plants feeding the soil. Grow veg and flowers to have great harvests of both. The land gardeners have a great list and notes for green manures in their book ‘cut flowers’ which makes the cover price worth it just for that.

I buy my seeds from Tamar and green manures both are great. And for small amounts from chiltern seeds.

I hope I’ve convinced you to try them. Or do you already use them? How have you found them?

---

*tiffle is my technical word for shaking the top layer of soil together with the seeds. I might use my fingers in small areas, between plants or a clawed rake style hoe.

The hummocks of green on either side of the short stakes are phacelia. I sowed these around late March to active the soil microrganisim and add nutrients before planting (or the dahlias rising). I cleared the phacelia in late May to see which dahlias survived. I’ll sow some mustard, fenugreek and buckwheat around the dahlias now as a companion. There won’t be much room in a few weeks time.

You can see the red flower of the red clover here. Sown around the eremurus. I’ll leave this in for another year. There is still a lot of weeds in this bed so I’ll pull the weeds and have another sow of the clover and see if it takes better this month all over the bed! The eremurus were fantastic this year. So many flowers.

You can see the lilac phacelia and yellow mustard. I left it too late to sow manures before winter last year, not clearing beds quick enough. These were sown in late March when it was mild.

Clearing green manures and weeds to top up the ends where they are low (still relatively new raised beds that need a bit more top soil)

Land Gardeners in pride of place with the classics!