Summer Cover Crops

Sorghum, Millet and Buckwheat Growing at Zilker Botanical Garden

What summer cover crops do you like to use? We spent a few minutes before the rain to sow summer cover crop seeds in the teaching beds at Zilker Botanical Garden. 

WHAT ARE COVER CROPS?
 Cover crops keep your soil web working by adding nutrients, suppressing weeds, controlling / redirecting insects and most importantly it is a carbon sequestration stragtegy. Your soil ecosystem will be balanced, fertile, and ready for fall planting. A cover crop is a crop you grow for the soil, and not necessarily for your plate but we are going to try hand-harvested some of them this year and will let you know how it goes. Many crops can be harvested and used as a forage for backyard chickens

 BENEFITS OF COVER CROPS

1. Soil Carbon Sequestration: Cover crops are an important soil carbon sequestration strategy. The roots and shoots of cover crops feed bacteria, fungi, earthworms and other soil organisms, which increases soil carbon levels over time.
2. Reduced erosion and run off. Cover crops reduce the impact of rain on the soil surface, reducing soil erosion and runoff . 
3. Increase Organic Matter Overtime, planting cover crops increases organic matter, leading to improvements in soil structure, stability, moisture, and nutrient holding capacity. Therefore improving the overall quality of the soil.
4. Fertilize soil  Cover crop stores nutrients from compost, mineralized organic nitrogen until the next crop can utilize them, reducing nutrient runoff and leaching. Certain cover crops, such as clovers, field peas and beans, add nitrogen to the soil, reducing the need for nitrogen fertilizer.
5. Reduced soil compaction. Deep tap roots of some cover crops such as Daikon Radish penetrate compacted soil layers, improving drainage while conducting more moisture deeper in the profile.
6. Suppressed diseases, pests and weeds. A cover crop provides a natural means of suppressing soil diseases and pests. It can also serve as a mulch or cover to prevent weed growth.
7. Source of Food While some cover crops provide an actual source of food for you, they also provide a source of food  for beneficial insects and wildlife.​

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RECOMMENDED VARIETIES FOR CENTRAL TEXAS

1. Buckwheat is very attractive to honeybees, hover flies, soldier beetles, parasitic wasps and parasitic flies which kill. Plus, predatory insects including assassin bugs, shield bugs, and predatory stink bugs. This plant steals soil nitrogen from its neighbors, tricking interplanted southern peas into fixing more nitrogen. Buckwheat has a short growing cycle and will reseed and grow three cycles through spring and summer. 
2. Millet is a tall, bunching grass that can get up to 12 feet high. The heads of some varieties of millet resemble that of a cattail. It is best suited for mid-summer plantings. The pearl millet has good nitrogen scavenging qualities, prevents erosion, Foxtail millet and pearl millet are the two with the popularity for cover crop use. 
3. Southern Peas are relatively drought tolerant and come in varieties that grow on vines or as a bush. As a legume, they provide a good source of nitrogen. We love purple hull peas and california cowpeas.
4. Sorghum is unrivaled for adding organic matter to worn-out soils. These tall, corn-like stalks, fast-growing, heat-loving summer annual grasses can smother weeds, suppress some nematode species and penetrate compacted soil.​
5. Sunflowers can attract predatory insects such as big-eyed bugs, wasps, lady beetles and predatory bugs. Sunflowers have a deep taproot breaking up some of those soil layers and bringing more different kinds of beneficial bacteria, fungi and microbes.

WHERE TO PLANT
So based on all of these benefits, choose an area in your garden, for a new area that you want to garden that. It is also a good crop rotation strategy. We will be planting cover crops where we grew corn, which uses a lot of the nitrogen in the soil. Additionally we will be planting cover crops where we grew sweet potatoes. This will ensure that we control any potential nematode problems. 

WHEN TO CHOP & DROP
Once you're ready to start your spring garden, you can cut down your cover crops by mowing, weed eating, or just chopping down with some loppers. Never, uproot your crops because you want to not upset the soil ecosystem or pull up the organic matter and nitrogen nodules that are in the roots of the plants. 

You can use  the organic matter as mulch, you dig a trench in your garden and compost the organic matter or add it to you compost bin.

WHERE TO BUY
Check your local garden store or purchase seeds online.