COVER UP, YOU'RE EXPOSED!

Are your gardens bare, exposed to the harsh elements, vulnerable to degradation during fall and winter? Don’t allow your gardens to be caught naked and defenseless this season, cover them up with green manure to optimize your gardening success next year.  What is green manure?  Despite the unusual name, it refers to the planting of cover crops such as winter rye, clover, hairy vetch and winter pea, all offering a wide range of benefits to both soil and the plants grown in your gardens.  Most cover crops are purchased as seed, and sown into vegetable beds largely during the fall, but also in early spring.  While most gardeners are ready for a well deserved breather after a season of arduous gardening, the payback for planting green manure far outweighs the effort required to do so.   The ritual of planting cover crops was crucial for early Roman agriculture, where the Roman Empire developed a more sustainable crop production system to support its ever growing population of citizens.   Sowing cover crops in your vegetable beds will enrich your gardening experience by: lessening your need for fertilizer, minimizing weeds, aerating the soil, warding off pest insects and disease, controlling soil erosion and reducing nutrient leaching in your gardens, ultimately saving you time and money!  You need not have a green thumb to work with cover crops, but simply the desire to maximize your food production and promote healthier, more balanced gardens. 
           
The most beneficial cover crops are those which have the natural ability to capture nitrogen from the atmosphere in a process known as nitrogen fixation. These nitrogen fixing plants are classified as legumes (like soybeans),  and have the ability to hold nitrogen in root nodules, which act as slow release organic fertilizer for your fruits, vegetables, herbs and even landscape plants!  Legume cover crops are team players, and have a mutually advantageous relationship with soil bacteria known as Rhizobia.  These bacteria creates nodules on legume roots that act as holding tanks for air borne nitrogen, and in return, the bacteria survives off of the simple carbohydrates produced as a waste product exuded through the roots.  Once your cover crop dies, either by natural means (winter weather) or through mechanical action, such as by shallow tilling, the root nodules release their stored nitrogen, making it available to your cultivated crops. This virtually free source of nitrogen is slow release, so your crops will have the ability to use it over several months, reducing your need for nitrogen fertilizer.  Other cover crops work by creating a network of roots that construct a sort of net, helping to hold your soil in place, preventing soil loss and nutrient leaching that would typically occur on bare soils.   Yet other green manure crops deeply penetrate the soil with large root systems, and act as a siphon to pump nutrients from deep within the soil,  transporting them to the soil surface where more shallow rooted fruits and vegetables can take advantage of those hard-to-reach nutrients and minerals. Simultaneously, these deep rooted cover crops aerate the soil by creating channels that improve air movement and drainage.  Cover crops are also considered companion plants, because many are known to attract beneficial insects and soil microbes to your gardens, where they will stand guard against rivaling pest insects and disease.  Lastly, cover crops act as a living mulch to shade out weeds, reducing the chance for weed invaders that may otherwise compete with your valuable crops for moisture and nutrients.

The number one way to get your garden soils primed for an over seeding of cover crops is by evenly covering your entire garden bed with a couple inches of well decomposed organic debris.  Finished compost is similar in consistency to soil, only much more biologically active, and richer in minerals and nutrients.  The benefits of spreading compost are as vast as the cover crop that follows.  Not only will compost help to expedite cover crop seed germination, but also sustain the crop once it has established.   As important, quality compost often contains the beneficial Rhizobia bacteria required for nitrogen fixation, since your soils may not harbor this organism otherwise.  Topdressing your beds with compost is a routine that builds soil quality and plant health, however, if you decide to forgo this step, simply scratch and loosen the upper crust of your garden bed with a hard rake, broadcast your seed on bare soil, rake them in, and then lightly tamp the soil with your feet or the back of your rake to make sure that your seed makes contact with the soil.  This step will improve germination, and keep your cover crop seed out-of-sight-and-mind from birds and other seed eaters.  You can sow cover crops on empty garden soil by completely blanketing the beds with seed, or you can sow them amid  edible crops, a technique better known as intercropping.  This practice works best if one of the crops is shallow rooted and the other deep rooted, or if one crop grows tall while the other stays shorter to prevent competition.  There are two ways this can be accomplished.  The first method is completed by seeding your cover crop 3-4 weeks prior to your edible crop, and then removing small patches of cover crop to provide enough space for your edibles to establish. Or, undersow your cover crop once your edible plants have established for a month. Green manure will offer your edible crops and gardens all the above benefits, plus help to cool the soil, reducing your need for irrigation.

Our favorite annual cover crops are: Winter Rye, Buckwheat, Cow Peas, Winter Peas and Crimson Clover.  The best perennial cover crops are: Hairy Vetch, Red Clover, White Dutch Clover, Lespedeza, Purple False Indigo and Lupine.  Try mixing several cover crop varieties into a single bed area, as they all work together synergistically to improve soil and crop health.  An alternative to cover crops is the practice of mulching, and many choices are available such as pine straw, wood chips, and pine bark, all promoting plant and soil protection through the harshest months of the year.  Don’t allow your gardens to be caught in the nude this fall, clothe them lovingly with beneficial cover crops, and your gardens will thank you with more abundant harvests, reduced work and less cost.  Marvin’s Organic Gardens would be glad to help you cover all the bases this fall, with the most suitable cover crops and landscape plants for your yard and gardens.  Fall is for planting!  Go Organic. It’s Only Natural!