No matter how healthy your vegetable plants start off in the spring – no matter how carefully you water – how perfectly it rains, or how much of the sun’s rays find their way to your garden – your plants are only going to turn out as good as the garden soil you plant them in. Period.
Vegetable crops like tomatoes, peppers, corn and cucumbers take a heavy toll on the soil’ structure and make-up. They devour valuable nutrients as they grow to produce the very fruits and vegetables we love to eat. Eventually, after a few years – even the best of soils will begin to break down and weaken if not replenished and re-energized. Soil that becomes weak in nutrients will result in successively weaker crop yields that are also increasingly prone to disease and pests.
So what is the best way to keep your garden strong? Feed your garden soil!
And no – we’re not talking about heaping on generous amounts of expensive synthetic fertilizers. Those are temporary fixes to a problem that can leave your soil weak, unstable, and full of excess salts and chemicals.
The real answer lies in adding back natural nutrients to the soil – and one of the best ways to do that is with a “green manure crop” in the spring – before you plant your garden or raised beds.
Planting A Green Manure Crop In Your Garden Or Raised Beds In The Spring
We talk a lot about cover cropping in the fall – and for good reason. Fall cover crops plays a vital role in developing and keeping garden soil beds full of rich organic matter. They minimize soil erosion and hinder the establishment of weeds, and then feed your soil with organic matter when turned over in the early spring.
But in the spring – we add a green manure crop to put back even more organic material prior to the vegetable garden planting. It’s quick, easy – and pays huge dividends!
A lot of people are confused by the term “green manure”. First of all, it doesn’t smell and it’s certainly not a by-product from animals.
So why the name?
Green manure is the term given to a cover crop that is grown specifically to be turned right back into the soil to replenish valuable nutrients and organic matter. Much like a farmer spreads horse, cow or chicken manure on his fields to fertilize and replenish – growing and digging in a bright green cover crop has the same effect and benefits. It’s the same concept as why fresh-cut green grass is great to add to a compost pile. In its fresh-cut green state, grass is a valuable nitrogen source that heats your compost pile up. Green manure crops do the same, releasing nitrogen back into the earth as they slowly decompose. Consider it almost a sacrificial offering to the soil 🙂
When a cover crop such as annual clover, rye or hairy-vetch are young, vibrant and bright green – they are at their absolute height of nutritional value. Their root nodules below the soil help to “fix” nitrogen levels – and the green matter that is turned back into the soil gives off additional nutrients and nitrogen as it decomposes during the summer months. All of which serves to replenish the soil and feed your summer crop of vegetables.
Green manure crops also provide many of the same benefits that fall cover crops give – helping to loosen the soil with their fast and deep growing roots and protecting the surface topsoil from heavy spring rains and erosion. All the more reason to incorporate them into your garden plan!
So when and how do you plant them?
We will turn our fall cover crop over in the soil beds about 4 to 6 weeks before we plan on planting our vegetables (about mid-march if the weather allows). At that point we will plant the spring “green manure” cover crop seed right into the soil, raking the soil out lightly after turning it over and spreading our seed. The new seedlings emerge in as little as 7 to 10 days, and by the time we are ready to plant our vegetables in Mid may – it has filled in with a strong thick stand of growth. Then, we simply turn them under again with the pitchfork – and plant our summer garden. As the green manure crop starts to break down – it releases its energy back into the soil and provides nutrients for the new crops. If you didn’t plant a fall cover crop, a spring green manure crop can be even more valuable to getting your soil back on track!
Annual rye, annual clover and hairy vetch are all great choices as green manure crops – and can usually be found at your local feed store.
Will I get weeds from them later?
In short – no! These are annual varieties – so once you till them into the soil as young green plant material – they wont come back like stubborn weeds. Furthermore – you incorporate them back into the soil quickly – so the plants don’t have the ability to establish seed heads or seeds that could become a problem. In fact – using cover crops in the fall and spring can greatly diminish your weed problems by keeping the soil from being barren and open to drifting weed seeds – and the thick, fast growing growth crowds out competing weeds.
Cover crops and green manure crops simply work. They keep your soil healthy and alive, let your plants thrive – and most importantly, are 100% natural.
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– Jim and Mary