Cover Crops

[Susan BBPM]

I'm quite keen to use cover crops extensively but there are big gaps in my understanding. Can anyone (@Meadowlark) fill in the gaps?

I'm a little unclear about what to use and when to use it.

So for example, I can think of a variety of different scenarios that would need different crops - what should you use and when? In all the following cases, what crops are suitable if you can afford to dedicate a year to soil prep vs what to use if you need to use a food crop? Also keep in mind some of us have short growing season, cold winters and cool summers!

1. A new bed that's previously had weeds or grass in it.
2. An overwintering crop to use after, say, onions (that are harvested late July/mid season).
3. An overwintering crop to use after, say, carrots (that are harvested october/late season).
4. Is there anything worth using if your bed becomes vacant in October and you plan on planting another crop in late March?

What are your thoughts in using covercrops like clover as a permanent mulch? Clover wants to grow here. It seems to me it might be an idea to sew clover in beds and leave it there - it's easy enough to tear away enough of it to make a planting hole?

 

[Meadowlark]

I just did a search on "cover crops in Scotland" and it yielded several excellent articles on cover crops discussing what to use and when to use it in Scotland. Those articles appear to be excellent "gap fillers". In addition, I would try to talk to local farmers about what they use successfully.... local knowledge is invaluable.

My climate is warm/hot intensive and yours appears to be cool/cold intensive. Very different. You have to find what works in your local environment hence the suggestion to consult with local cover crop users.

Having said that, legumes such as clover(s), vetch, peas (Austrian), and alfalfa would certainly be on my radar for Scotland along with small grains (oats, Elbon rye, etc.) and root crops like turnips and radish which are cold hardy and great provisors of weed suppression and soil building. I'm not knowledgeable on using any of these in a "no dig" approach and in fact, I find turning them under in preparing a planting bed provides much of the benefits to be accrued re soil regeneration.

As related to permanent mulch, that seems to be contrary to a fundamental tenant I employ in gardening which is rotation. Otherwise, the use of clovers would certainly be central to any strategy I would employ in your environment. The fact it wants to grow there is clearly a positive indicator for its use.

There is much to learn on using cover crops for soil regeneration, but the journey of learning can be the most enjoyable part of it. It never ends.

 

[YumYum]

Cover crops don't have to be used to input minerals, they can also be used to pull minerals out of the soil, but you can't till them back in or you put the minerals right back. One such thing comes to mind is if your soil had too much sulfur, I'm guessing you could plant onions to pull sulfur out of the ground, then eat or discard the onions. Sulfur is what makes onions taste hot but onions are made of other minerals so those come out too.

Having the soil tested would go a long way in figuring out what you need to do. Nitrogen is usually the first thing to go so legumes make a good cover crop in most cases. I'm sure you could fall into a rabbit hole trying to figure out the perfect cover crop to use.