Tag Archives: cover crops

Cover Crops: Improve Clay Soils

Utisols, also known as red clay soils, are the most common soil type in the Southeastern United States. They’re what many Southern Exposure Seed Exchange customers and seed growers garden. While many gardeners may wish they had soft, dark loam, clay soils aren’t terrible. Like any soil, they come with their own set of advantages and disadvantages. In this post, we’ll discuss the features of clay soil and how you can use cover crops to improve it.

Advantages of Clay Soil

Clay soils aren’t perfect, but they come with their own set of advantages. Clay soil holds water for much longer than sandy soil, especially when you mulch it, helping you cut down on that water bill.

Clay soil is also high in nutrients and minerals that plants need, the perfect starting place for a garden. All of those tiny clay particles are also very good at holding onto nutrients from amendments that tend to leach out of sandy soil quickly. 

While clay soils are dense, that density helps perennial plants and fruit trees hold tightly to the ground and withstand wind, storms, and erosion better than in light, sandy soil. 

Disadvantages of Clay Soils

If you’ve ever had to till or dig garden beds in clay, you’re probably already familiar with one of the main disadvantages. Clay soil is heavy. This makes working it quite troublesome. When it’s wet, it’s heavy and sticky. When it’s dry, it’s often brick-like.

This same characteristic also means that clay soil compacts easily. Especially when the soil is wet, walking on it or using equipment on it can cause severe compaction. Heavy, dense clay soil can be especially tough to deal with if you’re hoping to grow root vegetables like carrots. 

Some of its advantages can have a negative side, too. If you live in boggy or low areas, clay soil’s ability to hold water isn’t ideal and can lead to issues like root rot. Additionally, its ability to hold little particles also means that it can hold onto bad particles like salt, and changing the soil’s pH may take some serious work. 

What Do Clay Soils Need?

The best thing you can do to amend clay soil is to add plenty of organic matter. There are many ways to add organic, including compost, mulch, leaf mold, peat moss, and cover crops.

Don’t add sand. It can be a tempting choice to improve drainage, but it gets stuck between the clay particles and creates denser, brick-like soil. 

Though somewhat slow, cover crops are an excellent, affordable way to build up organic matter in the soil each season. They can help add nutrients and break up hard pans and compaction, allowing air and water into the soil.

White Clover (cover crop for clay soils)Using Cover Crops to Improve Clay Soils

There are several great cover crops for improving clay soil, and fall is a great time to plant them! While all cover crops are good, some excel in specific areas.

Cover Crops to Add Organic Matter

Clover

Clover is an all-around good choice for cover cropping. Clovers fix nitrogen and produce plenty of organic matter. White Clover can be sown in late winter, spring, summer, or fall. It also makes an excellent living mulch for pathways. Mowing these paths and collecting the material with a bagger gives you a consistent supply of mulch and organic matter for the beds they border.

Winter Wheat

Though generally grown as a cereal, winter wheat is also an excellent cover crop. It produces a large amount of mulch material, adding plenty of organic matter to the soil. It’s also easy to kill and less likely to get weedy than other cover crops. It’s also a great cover crop for no-till systems. Mow it down in the spring and transplant it into the beds.

Buckwheat

Buckwheat is one of the fastest-growing cover crops. It can create tons of organic matter in just 30 to 45 days. We recommend sowing buckwheat with crimson clover for a fall or winter cover crop. The buckwheat acts as a nurse crop for the crimson clover during the heat of the day. In the fall, the buckwheat is killed by frost.

Cover Crops to Break Up Compacted Soil

Daikon Radishes

Daikon Radishes are popular for compacted soils because their tough, fast-growing roots easily break up the soil. They put on rapid fall growth, and winter kills them where temps regularly get below 20°F. 

The crop residue from daikons decomposes quickly and releases its nitrogen early. The channels created by radish roots improve infiltration, drainage, soil warming, and growth of the next crop’s root systems. 

Rye

Rye is a great winter cover crop with an extensive root system, making it an excellent choice for improving soil structure in compacted beds. Rye is very good at releasing phosphorus and potassium. It also stabilizes excess soil and manure nitrogen. 

Many of us gardeners of the Southeast grow our crops in red clay soils. While we’re thankful for the nutrients and other advantages they bring, they also have a few downfalls. One of the most affordable ways to improve these soils is to grow cover crops. Choose one of these cover crops and sow this fall to improve your clay soil this winter. 

Cover Crops for Beginners

We’ve mentioned cover crops in many articles on the blog before. These humble plants are an integral part of organic farming with many benefits for gardens, big and small. Today, we’ll take a deeper look into cover crops and how to use them for beginners.

Why Should I Grow Cover Crops?

There are many different types of cover crops which are all grown for specific reasons. Cover crops prevent erosion, decrease weed pressure, add organic matter to the soil, add nitrogen, and retain soil moisture. They also help provide food and habitat for beneficial insects and microorganisms. 

Choosing Cover Crops

As I mentioned above, there are many different cover crops. Generally, we can divide them into a few different categories by the primary purpose they serve in your crop planning.

Nitrogen Fixers

Nitrogen fixers are plants with a symbiotic relationship with bacteria known as Rhizobium. These bacteria colonize the nodules on the plants’ roots and allow the plant to take nitrogen from the air and use it. When these plants die or are cut back and added to the soil, they add nitrogen. Some nitrogen fixers include:

  • Red Clover
  • Crimson Clover
  • White Dutch Clover
  • Sunn Hemp
  • Hairy Vetch
  • Austrian Winter Peas
  • Iron and Clay Southern Peas
  • Alfalfa

All of the clovers are excellent for attracting bees to your garden. Perennial white dutch clover is a great choice for permanent garden pathways and can be mowed and used as mulch around plants. 

Austrian winter peas are a great winter option in zone 6 and up. Their shoots are edible and make excellent additions to winter salads. On the other hand, massive sunn hemp plants are day-length sensitive and do best as a summer cover crop. It thrives even during drought and is excellent for suppressing nematodes. 

Deep Rooted Cover Crops

Cover crops with large or deep roots are essential in areas with heavy clay or compacted soils. These large rooted crops help break up hard pans, add pockets for air and water, and add organic matter. A couple of our favorites are:

  • Deep-Till Radishes
  • Alfalfa

Deep-Till radishes produce large, fast-growing roots for aeration and breaking up compacted soils. They also have biofumigant properties, which are excellent for suppressing diseases and pests. They winter-kill in areas where temperatures reach below 20°F. 

Alfalfa is a nitrogen fixer with deep roots and is good at gathering water and nutrients from deep in the soil. It will add nitrogen and organic matter to the soil. Plus, it’s very cold-hardy, making it perfect for early spring or late fall plantings. 

Buckwheat (cover crops)Grasses & Mulchers

The main job of these cover crops is to produce a lot of organic matter. They form a ground cover that helps prevent soil erosion and gathers nutrients from the soil. They make excellent mulch in no-till systems and add nutrients and organic matter to the soil as they decompose. Some great options include:

  • Hulless Oats
  • Winter Rye
  • Wheat
  • Buckwheat

Rye is a good choice if you’re looking for a winter cover crop. It has an extensive root system for improving soil structure, suppressing weeds, and enhancing soil life. It’s also able to stabilize excess nitrogen from heavy manure applications. A combination of rye and vetch is a favored cover crop for no-till tomato planting. 

Buckwheat is the best choice when you want something fast, producing a green manure crop in 30 to 45 days! It’s great for out-competing weeds and providing mulch for fall crops when planted in midsummer. The little white flowers attract beneficial insects, including parasitic wasps. 

Growing Cover Crops

Cover crops can be grown year-round. It’s a good idea to plan to leave your soil bare as little as possible. Sow cover crops in beds as soon as others are finished, whether that’s the middle of summer or fall. You can also use cover crops to provide sections of your garden with a needed boost of nutrients or organic matter or to suppress pests and diseases.

Knowing when you want to plant will help you determine which cover crop is appropriate for your situation. Some cover crops like winter rye, hairy vetch, and Austrian winter peas make excellent winter cover crops when planted in the fall. Other crops like buckwheat or sunn hemp will perform much better for summer crops. 

Once you’ve decided on a variety, you should follow the seeding instructions. It’s essential to follow the recommended seeding rates. Seeding your crops too thinly won’t achieve the desired benefits. 

Terminating Cover Crops

This step may sound scary, but it just means you’re ending the cover crop’s cycle so that you can plant something else. This process is typically done by mowing, weed whacking, scything, or tilling. In a no-till system, you can often use the material as a mulch and transplant it right into it or rake some back for direct seeding.

Typically, you should terminate cover crops before they go to seed. However, sometimes you may decide to let a quick-growing crop like buckwheat go to seed and grow again. Remember that you may have to continue to weed it out for a while after this; cover crops are good at suppressing weeds because they’re a bit weedy in nature themselves!

Winter Kill 

Nature also lends a helping hand for certain fall-planted cover crops. Those crops that are sensitive to frost or cold temperatures will winter kill and begin decomposing into the soil on their own. Some no-till farmers will plant directly into this crop residue in the spring.

Growing cover crops is quite simple and has many benefits. This fall, try growing cover crops in your garden to add nutrients and organic matter, reduce erosion, and encourage beneficial insects and soil organisms. 

 

 

Late June Garden Checklist

Here in the Southeast, June is an exciting time in the garden. Depending on your zone, you’ll be harvesting various crops like the last of the spring snap peas and broccoli and the first tomatoes, cucumbers, and squash of the year. It’s also a time where staying on top of the garden chores is critical for continued production into the late summer and fall. This late June garden checklist will help you stay on track and keep your garden healthy and productive. 

June Maintenance

The late June garden to-do list includes some general maintenance tasks to keep your garden growing strong.

Weed, Weed, Weed.

No one loves to spend time weeding, but this time of year is critical. Keep the weeds knocked back to ensure they don’t steal precious water and nutrients from your rapidly growing crops. 

Harvest Regularly

Staying on top of harvesting is essential. You want to pick and use or preserve produce at its peak and encourage continued production. Many crops like cucumbers, summer squash, and green beans will produce more if picked regularly. Allowing the fruit of these crops to fully mature, like you would to save seed, will tell the plant it’s time to die back and stop producing. Check out our previous post, Food Preservation Resources, for information on putting up your harvest.

Add Compost

Heavy feeding crops like corn, tomatoes, and peppers benefit from extra nutrients this year. Sidedressing these crops with good, finished compost can give them a boost to ensure good production. Sidedressing with compost when the plants are flowering is ideal.  

You should also add an inch or two of finished compost to a bed before sowing new successions. This will ensure your soil has enough nutrients to maintain good production.

Stay on Top of Watering

In the Southeast, the temperatures really begin to climb in June. This time of year and further into the summer keeping the soil cool and moist will improve production. A wilting plant is not the only sign of water stress. Deformed cucumbers are often a sign of too little water. Blossom end rot in tomatoes, eggplants, and peppers may also indicate water deficiency, as insufficient water can prevent the plant from taking up enough calcium. 

Remove Old Plants

Remove any plants that are no longer producing, like peas or plants past their prime. You can replace these plants with successions or cover crops, which we’ll discuss below.June garden checklist

Starting the Fall Garden

One of my mistakes as a new gardener was waiting too long to start a fall garden. If you live anywhere with a late first frost date, it can be easy to assume that you have plenty of time to grow crops in the fall. 

Unfortunately, it’s not just the temperature that affects how your garden grows. Dwindling hours of daylight slows crop growth in the late summer and fall.

To know when to sow summer successions and fall crops in your garden, take your first frost date and count backward by the days to maturity for a chosen variety plus an additional 14 days for cool-weather crops and 21 days for frost-tender crops (this accounts for slowed growth). 

For example, if your first frost date is November 15th and you want to grow another succession of Anne Arundel Muskmelons, you should plant your last succession by August 7th at the latest. To get that date, I started on November 15th and counted back 80 days (Anne Arundel’s days to maturity) and then counted back another 21 days to account for decreased daylight.

Late Summer & Fall Crops

Many crops can be planted in June, July, or even later, depending on your USDA zone. Some great options for late summer successions and fall crops include:

  • Snap Beans
  • Summer Squash & Zucchini
  • Cucumbers
  • Cabbages
  • Cauliflower
  • Broccoli
  • Turnips
  • Rutabagas
  • Beets
  • Carrots
  • Greens

When sowing and transplanting this time of year, you’ll want to take extra care to keep plants and seeds cool and moist. Transplant in the evening or on overcast days. Water often and use shade cloth or other plants to keep some afternoon sun off of cool-season crops like lettuce. Place seed trays in a root cellar or fridge to help seeds like cabbage and broccoli germinate in hot weather.

Heat-Tolerant Greens

As spring turns to summer, the last of the cool season greens are being harvested. Any leftover will soon bolt and turn bitter (pollinators love the flowers, though). Thankfully, there are a few ways to continue green production in the hotter parts of the year. 

Here are some great heat-tolerant greens to try:

Using row cover and keeping the soil moist can be especially helpful for lettuce.

Cover Crops

If you have empty beds that you aren’t going to fill with crop successions, it’s an excellent time to start some cover crops. Cover crops suppress weeds, keep the soil moist, and add nutrients and organic matter. Some cover crops you can sow in June include:

  • Buckwheat
  • Sorghum Sudan
  • Cowpeas
  • Soy
  • Millet

Check out these other Summer articles and tips:

Keeping up with summer garden chores is a demanding but rewarding process. Following this June garden checklist and completing these essential maintenance tasks, plus succession and fall planting, will allow you to keep fresh food on your family’s table through late summer and fall.