Going green...with manure?

During these seemingly endless, frigid days it is easy to pass by the Victory Garden outside of the museum’s Stars & Stripes Cafe and think that nothing’s happening. There are no bright colors, no vegetables, nothing to take notice of. To the contrary—the garden is in full swing!

When you look out the cafe window, it looks as if our lawn mower has broken and the grass has grown to almost a foot in areas. The overgrown “grass” is actually winter rye, a cover crop that we planted in October and will be using as a green manure. Okay, so what is a green manure? It may sound like a Dr. Seuss meal gone bad, but it’s actually an environmentally friendly and sustainable product that incorporates the benefits of one season’s crop into the needs of the next. In short, green manure is a natural fertilizer.

Here’s how green manure works: The winter rye cover crop in the Victory Garden helps protect against erosion, retain nutrients that might otherwise be leached from the soil, suppress the germination and growth of weeds, cycle nutrients from the lower to the upper layers of the soil, and—in the case of legumes—leave to the following crop a considerable quantity of nitrogen. There are still more contributions of green manure: improved soil structure, additional organic matter, enhanced drought tolerance, and increased nutrient availability for plants. 

Wow! Sounds like a great deal (and it is), but don’t go into the shed tomorrow and throw out all of your fertilizers. Green manure is just one way of contributing to the health of your soil.

Although there are many cover crops to pick from, winter rye is a good choice because of its resistance to the cold temperatures. It also creates a lot of biomass, which increases the organic matter. Sow winter rye in September or October, depending on what growing zone you’re in, and leave it alone. It practically does all of the work on its own. In late March, the winter rye in the Victory Garden will be incorporated into the soil to start the decomposition dance. When the soil warms up enough, all of the millions of micro-organisms will awaken to begin breaking down the cover crop, forming a rich, dark, and spongy soil that the plants will be itching to sink their roots into. It will become green manure!

So, next fall, instead of leaving the soil bare after the vegetable plants are pulled, try planting a cover crop and make next year’s harvest even better. To learn more about cover crops, their time of planting, and their benefits, visit the USDA Alternative Farming Systems Information Center. Happy gardening!

Joe Brunetti is a Smithsonian horticulturalist for the National Museum of American History.

Comments

[Z]

During these seemingly endless, frigid days it is easy to pass by the Victory Garden outside of the museum’s Stars & Stripes Cafe and think that nothing’s happening. There are no bright colors, no vegetables, nothing to take notice of. To the contrary—the garden is in full swing!

[Steve]

I'll echo the comments of a previous contributor about chicken manure. I live across the road from a farm that has hundreds of chickens. Between us we've discovered that dried chicken manure sprinkled over grass makes excellent fertiliser! Helps the mower to glide over the grass easier for some reason too!

[Jon]

Thanks for posting. i'm just experimenting with my first lot of green manure this year, to keep my new raised bed ticking over before i'm ready to plant.I'm also going to compare mulching using composted grass clippings from my push mower and see if there are any differences in results.

[mark a white]

I have never thought about using Rye as its mainly farmers that grow it in the Uk though when roatating crops I plant Maze to help break up the soil,

Then I would Dig up trenches and also ad composte and manure put some soil back over the top and plant potatoes putting some extra in to leave there to rot down, Ready to dig over to plant winter broccali and spring cabbage,

I will look into finding some Rye seeds and give it a go,

[chickens]

Instead of green manure, we have system of rotating chickens with our vegetable planting. As per permaculture methods, we grow a variety of vegetables in a shaped piece of ground that coincides with the chicken enclosure shape. eg a circle works quite well - about 3m in diameter. When all the vegetables and herbs have been harvested, we place the chicken enclosure over the vegetables for them to finish them off and end up with a wonderfully worked over patch together with lots of chicken manure. Ready for the next lot of seasonal vegetables and herbs to be planted. What we now need to look at is whether or not to include something like winter rye I guess. Legumes are always included somewhere along the way too.

[Jon Frank]

Joe, you wrote: "Wow! Sounds like a great deal (and it is), but don’t go into the shed tomorrow and throw out all of your fertilizers. Green manure is just one way of contributing to the health of your soil."

This is a very important statement so many people in the organic gardening movement miss. As gardeners we are in fact stewards of the soil helping plants produce carbohydrates combined with minerals to produce food. Here is an article I wrote talking about increasing that process.
http://www.aglabs.com/newletters/harvesting_solar_energy.html

There is a place for both fertilizers and green manure crops.

[Denver]

There is so much time on hand that you really don't know what to do. How about adding green manure to your garden? Soils of various types are necessary for growing shrubs as well as trees. Before the tree is actually planted it is very necessary to check the type of soil it is going to be planted in.

[Schwinn]

A lot of work is involved in rejuvenating the soil in your garden area. Lumps if any should be thoroughly broken down first. At the bottom a layer of ash, sand as well as cinders needs to be placed. To improve the quality of the soil, a great addition would be peat, clippings of grass which has been mowed down, compost, dried leaves, manure, etc. Top layer of the soil should be kept ready for plantation purpose all the time.

[David Cameron Schneider]

This article has spawned some interesting comments on an old subject - crop rotation. It even goes back to Bible times of leaving the ground fallow one out of seven years; this, of course, allowed other vegetation to grow and then be plowed under, hopefully of the legume family, to then fertilize the soil again.

[EggLayingChickens]

The idea of a cover crop on our small backyard garden intrigues me, especially since our chickens go through the garden in the late summer/ early fall and make it pretty bare. I think a good cover crop, like the winter rye mentioned here, could help keep the garden more fertile for the next growing season. Thank you for the idea!

[sue ingram]

Instead of green manure, we have system of rotating chickens with our vegetable planting. As per permaculture methods, we grow a variety of vegetables in a shaped piece of ground that coincides with the chicken enclosure shape. eg a circle works quite well - about 3m in diameter. When all the vegetables and herbs have been harvested, we place the chicken enclosure over the vegetables for them to finish them off and end up with a wonderfully worked over patch together with lots of chicken manure. Ready for the next lot of seasonal vegetables and herbs to be planted. What we now need to look at is whether or not to include something like winter rye I guess. Legumes are always included somewhere along the way too.

[Hal Merrill]

I agree with using fava beans as a cover crop. Mung beans worked well too and the seed was less expensive.

[Lora]

I have been using fava beans as a cover crop for the last couple of years but am thinking it would be good to try something new, I am going to do more research into rye grass to see if it is right for my zone!

[Joseph Acai]

Manure may not be the most pleasant fertilizer to use, but it certainly is effective!

[Garden Manuals]

Gardening is so relaxing and a wonderful way to spend time outdoors. It is one of my favorite hobbies that I love to share with others online! Thanks for taking the time to write this post, I always learn so much about gardening from many different sources online!

[Kathy J, Washington Gardener Magazine]

Great to see the use of a winter cover crop and right here on our Mall. I'll have to come down soon to take a few photos of my own. Can't wait to see how the "Victory Garden" grows this year.