Using a Buckwheat Cover Crop in Raised Bed Gardens

Using a Buckwheat Cover Crop in Raised Bed Gardens

2020 has not been the most pleasant year in many ways.  However, one positive experience I’ve had in my raised bed vegetable garden has been the use of a cover crop, Buckwheat (Fagopyrum esculentum)! Use of cover crops, a catch-all term for many species of plants used to “cover” field soil during fallow periods, became popular in agriculture over the last century as a method to protect and build soil in response to the massive wind erosion and cropland degradation event of the 1930s, the Dust Bowl.  While wind erosion isn’t a big issue in raised bed gardens, cover crops, like Buckwheat, offer many other services to gardeners:

Buckwheat in flower behind summer squash. Photo courtesy of Daniel Leonard.

  • Covers, like Buckwheat, provide valuable weed control by shading out the competition.  Even after termination (the cutting down or otherwise killing of the cover crop plants and letting them decompose back into the soil as a mulch), Buckwheat continues to keep weeds away, like pinestraw in your landscape.
  • Cover crops also build soil. This summer, I noticed that my raised beds didn’t “sink” as much as normal.  In fact, I actually gained a little nutrient-rich organic matter!  By having the Buckwheat shade the soil and then compost back into it, I mostly avoided the phenomena that causes soils high in organic matter, particularly ones exposed to the sun, to disappear over time due to breakdown by microorganisms.
  • Many cover crops are awesome attractors of pollinators and beneficial insects. At any given time while my Buckwheat cover was flowering, I could spot several wasp species, various bees, flies, moths, true bugs, and even a butterfly or two hovering around the tiny white flowers sipping nectar.
  • Covers are a lot prettier than bare soil and weeds! Where I would normally just have either exposed black compost or a healthy weed population to gaze upon, Buckwheat provided a quick bright green color blast that then became covered with non-stop white flowers. I’ll take that over bare soil any day.

Buckwheat cover before termination (left) and after (right) interplanted with Eggplant. Photo courtesy Daniel Leonard, UF/IFAS Calhoun County Extension.

Now that I’ve convinced you of Buckwheat’s raised bed cover crop merits, let’s talk technical and learn how and when to grow it.  Buckwheat seed is easily found and can be bought in nearly any quantity.  I bought a one-pound bag online from Johnny’s Selected Seeds for my raised beds, but you can also purchase larger sizes up to 50 lb bags if you have a large area to cover.  Buckwheat seed germinates quickly as soon as nights are warmer than 50 degrees F and can be cropped continuously until frost strikes in the fall.   A general seeding rate of 2 or 3 lbs/1000 square feet (enough to cover about thirty 4’x8’ raised beds, it goes a long way!) will generate a thick cover.  Simply extrapolate this out to 50-80 lbs/acre for larger garden sites.  I scattered seeds over the top of my beds at the above rate and covered lightly with garden soil and obtained good results.  Unlike other cover crops (I’m looking at you Crimson Clover) Buckwheat is very tolerant of imperfect planting depths.  If you plant a little deep, it will generally still come up.  A bonus, no additional fertilizer is required to grow a Buckwheat cover in the garden, the leftover nutrients from the previous vegetable crop will normally be sufficient!

Buckwheat “mulch” after termination. Photo courtesy of Daniel Leonard, UF/IFAS Calhoun County Extension.

Past the usual cover crop benefits, the thing that makes Buckwheat stand out among its peers as a garden cover is its extremely rapid growth and short life span.  From seed sowing to termination, a Buckwheat cover is only in the garden for 4-8 weeks, depending on what you want to use it for.  After four weeks, you’ll have a quick, thick cover and subsequent mulch once terminated.  After eight weeks or so, you’ll realize the plant’s full flowering and beneficial/pollinator insect attracting potential.  This lends great flexibility as to when it can be planted.  Have your winter greens quit on you but you’re not quite ready to set out tomatoes?  Plant a quick Buckwheat cover!  Yellow squash wilting in the heat of summer but it’s not quite time yet for the fall garden?  Plant a Buckwheat cover and tend it the rest of the summer!  Followed spacing guidelines and only planted three Eggplant transplants in a 4’x8’ raised bed and have lots of open space for weeds to grow until the Eggplant fills in?  Plant a Buckwheat cover and terminate before it begins to compete with the Eggplant!

If a soil building, weed suppressing, beneficial insect attracting, gorgeous cover crop for those fallow garden spots sounds like something you might like, plant a little Buckwheat!  For more information on Buckwheat, cover crops, or any other gardening topic, contact your local UF/IFAS County Extension Office.  Happy Gardening!

Now is Time to Use Solar Power Against Soil Pests

Now is Time to Use Solar Power Against Soil Pests

North Florida vegetable gardeners have made it to summer and now the plants and gardeners are starting to give in to the heat and humidity. The squash has likely succumbed to squash vine borers, many of the tomato varieties are having trouble setting fruit, stink bugs are all over, and gardeners easily wilt by noon. This is a good time to use our oppressive heat to your advantage in the vegetable garden by solarizing the soil.

Graph of annual temoerature

We have reached the peak of heat. Use it to your advantage in the garden. Source: National Weather Service.

Soil solarization is a method of pest control that creates a greenhouse to heat up the soil in an effort to drive away pests. Pests that can be reduced with soil solarization include weeds, various soil-borne fungal pathogens, and nematodes. Weed seeds can actually be killed by the increased temperatures, sometimes as high as 140 degrees Fahrenheit, while fungi and nematodes are merely driven deeper into the soil layer as they try to escape the heat. Although they are not killed, this can help vegetable gardeners as it may take these organisms 3-4 months to repopulate in high enough numbers to cause damage. Soil solarization can be considered another tool in your integrated pest management (IPM) toolbox, along with other cultural, physical, and chemical means of pest control.

Picture of raised bed garden covered in plastic.

A raised bed being solarized over the summer. Source: Evelyn Gonzalez, UF/IFAS Master Gardener Volunteer.

To properly execute soil solarization, the site should be in full sun and the existing vegetation removed, either by hand or with a tiller or other implement. Tilling can help loosen the soil surface and allow heat to penetrate deeper in the soil horizon. Before being covered with plastic, the area should receive rainfall or be irrigated, as the water will help conduct heat to greater depths. The next step is to cover the area with plastic. Note that this can also be done over raised beds! Clear plastic is best for maximum solar radiation penetration. Black plastic will heat up mostly on the surface and opaque plastic sheeting may not let enough light in to get temperatures high enough. The plastic should be slightly larger than the area covered, as the edges will need to be buried to create an air-tight seal. It’s recommended to leave the plastic in place for at least six to eight weeks, just in time to begin fall gardening preparations.

It’s important to monitor the site while it’s “cooking” to look for any holes that might appear. Small holes can be repaired with duct tape, while large holes or rips in the plastic may require starting over. Overlapping strips of plastic is not recommended since too much heat will be lost.

You may be wondering what happens to all of the good soil microbes. Well, unfortunately, they are also either killed or suppressed. Fortunately, researchers have found that they are able to repopulate quicker than the pest organisms, especially in soils with a good amount of organic matter.

Much more information on soil solarization can be found in these two documents:

Introduction to Soil Solarization – https://edis.ifas.ufl.edu/pdffiles/IN/IN85600.pdf

Solarization for Pest Management in Florida – http://edis.ifas.ufl.edu/pdffiles/IN/IN82400.pdf

Also, please contact your local county extension office for more gardening tips.

It’s the Little Things in Life, like Mini Vegetable Gardening

It’s the Little Things in Life, like Mini Vegetable Gardening

Whether it’s the warm or cool season of the year, vegetable gardening is as popular activity as any. In writing articles, I usually discuss best management practices on a backyard garden scale. But, what if you don’t have much of a backyard?

Many Floridians live in apartments, condominiums, mobile home parks, or simply homes built on small parcel lots with little open gardening space. This doesn’t mean you can’t grow vegetables. You just have to be a bit creative and that’s when the fun starts. In addition to being an enjoyable activity, mini vegetable gardening can be practical and ornamental. Containers can fit almost anywhere in the landscape, such as porches, balconies, roof tops and that spot on your property where nothing seems to fit.

Tomato Bucket Gardening. Photo courtesy UF/IFAS Gardening Solutions.

There’s practically no limit to the kinds of containers one can use for mini vegetable gardening. Some examples are pots and pans, milk jugs, hollow concrete blocks, bushel baskets, trash cans, barrels, buckets and even plastics bags and “to go” food containers. As long as the container will hold soil and let excess water drain, you’re good to garden.

So, what can I use as a growing medium? Traditional garden soil will work fine. Mixing garden soil 1:1 with mushroom compost is also acceptable. Adding lightweight components to the soil mixture such as perlite or vermiculite will make it easier if you need move the container from time to time. This will also help with drainage. Sprinkling a handful of 6-6-6 or 8-8-8 fertilizer and gardening lime into the mixture will give plants much needed nutrients for development.

This growing medium will not require fertilizer applications very often. A small amount every two to three weeks should be adequate for most vegetable plants. Whether the fertilizer you choose is solution or dry form, be sure to use small amounts and water the product thoroughly into the root zone. A heavy application of fertilizer may cause plant burn.

So what vegetable crops grow best in containers? Most any crop will do well in containers. Some examples are tomato, pepper, eggplant, collard, cabbage, turnip, mustard, strawberry, broccoli, cauliflower and many herbs. Container gardening is a fun and rewarding hobby. You’ll enjoy both the activity and the delicious produce you’ve grown.

For more information contact your local county extension office.

Supporting information for this article was provided by Extension’s Emeritus Vegetable Specialist Jim Stephens of UF/IFAS Extension. More information can be found at this website: http://gardeningsolutions.ifas.ufl.edu/plants/edibles/vegetables/growing-vegetables-in-containers.html

UF/IFAS Extension is an Equal Opportunity Institution.

Yellow is Not a Normal Sago Color

Yellow is Not a Normal Sago Color

Photo by: Sheila Dunning

The first sign that something is going wrong in a plant is often a loss of the color green.  When a sago is forming all new yellow leaves it is a matter of concern.  Typically, this a common nutritional deficiency – manganese.  Sandy soils of the Panhandle have a hard time retaining nutrients.  Manganese and other micronutrient availability is highly influenced by soil pH.  Being an essential plant nutrient, manganese is critical to growth.  More specifically, it is the base of the metalloenzyme cluster of the oxygen evolving complex (OEC) in photosystem II (PSII).  I hope that means more to you than it does me.  Basically, manganese is part of the photosynthetic activity and since it isn’t very mobile in the plant, the new growth of sagos turns yellow.

If the nutrient deficiency isn’t corrected, the newly-formed leaves will become deformed and turn brown.  In a sago this is referred to as “frizzle-top”.  Many people believe the plant has a disease when they see the symptoms and may apply fungicides to no avail.  Keep in mind the discoloration of the affected leaves cannot be reversed.  However, manganese replacement in the soil will enable the sago to form normal leaves with the next growth phase. Damaged fronds can be removed later to improve the appearance of the sago over time.

Begin this process by determining the soil pH through a soil test.  Your local Extension office can help you obtain lab submission forms and explain the collection procedure.  Manganese is most available for uptake by sagos when the soil pH is between 5.5 and 6.5.  If the pH is above 6.5, larger amounts of manganese will have to be present before the plant can utilize it.  When the soil pH is below 5.5 the nutrient is quickly leached out of the soil during rain events.

To correct a manganese deficiency the sago plant will need to receive manganese sulfate.  The product is readily available at local nurseries, garden centers and building supply stores. The amount needed for each plant will vary with the size of the sago and the existing soil pH.  Sagos growing in sandy, acidic soil will require less manganese sulfate than those in high pH soils.  Refer to the package label for application rates.

Dirt is Good for You

Dirt is Good for You

Photo courtesy of Gabriel Jimenez at Unsplash.com.

Gardeners have always known, down to their bones, that getting down and dirty in the soil is good for you. My grandmother was a staunch believer in the beneficial, calming effect of pulling weeds and digging in the garden when she was angry or frustrated with life.

Pulling weeds, digging up plants, planting new plants and seeds, mixing in good compost to a new landscape bed – these are joys that bring gardeners into intimate contact with soil and all the abundant life within. Gardeners love that smell of good fertile soil. As do nature lovers of all sorts. Hikers love the earthy smell as they tromp through the woods – especially after a nice rain when the fragrance is especially fresh and sweet.

What causes the aroma that we are experiencing? Much of it is bacteria. Good bacteria. Healthy soil is a complex ecosystem containing a great biodiversity of species of plants, fungi, animals and bacteria. And much research is being done to identify and learn about the thousands of species living under our feet.

Scientists are now suggesting that a fatty acid found in the soil-based bacterium Mycobacterium vaccae may alleviate stress and stress related disorders in humans. Gardeners have always known there was something about the soil that was good and healthy for us. Now, we have the science to back it up!

Happy Gardening!