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!

Clean Up for the Fall Vegetable Garden

Clean Up for the Fall Vegetable Garden

A common question for gardeners at the end of the season is if one should till the soil or use no till practices.  Opinions vary regarding this question, even among Extension Agents.  However old crops harbor insects, both good and bad.  This phenomenon was noticed on some recently cut back tomato plants.  The intention was to cut the leftover spring garden tomatoes back to encourage fall production.  Instead, a host plant for mealybugs was provided.

Whitefly larvae on a tomato plant.

Mealybugs on a tomato plant. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

Mealybugs are soft-bodied insects that possess a covering of flocculent, white, waxy filaments.  They are about 1/8 inch in length and usually pinkish or yellowish in color.  Mealybugs have piercing-sucking mouthparts which they use to siphon fluids from the leaves, stems, and sometimes roots of many ornamental and vegetable plants.  Mealybug damage produces discolored, wilted, and deformed leaves.

One very common example of an insect pest likely to claim residence in your garden’s crop residue, are squash bugs. They like to overwinter on squash, cucumber, and other cucurbit crop residue.  If you choose to not till your garden and leave a portion of last seasons crop in your garden, then you should consider applying an insecticide to your spent crop at the end of the season.  A product containing a pyrethrin or pyrethroid as an active ingredient would be a good broad spectrum insecticide to control any pest that may reside on plant residue.  More information on pyrethrins and pyrehtroids can be found at the EPA webpage: Pyrethrins and Pyrethroids.  If you choose to apply an insecticide, it is important that you follow the information on the label regarding pollinator protection.  Another option is to plant a trap crop on the edge of your garden to help attract pest insects away from your desired crops.  More information on trap crops can be found in the EDIS PublicationIntercropping, Pest Management and Crop Diversity.

An adult squash bug on a zucchini leaf.

An adult squash bug on a zucchini leaf. Photo Credit: Matt Lollar, University of Florida/IFAS Extension – Santa Rosa County

So the answer to the till or no till question is…it depends.  It is really up to the gardener.  Yes, the residue from crops will add nutrients and organic matter to your soil, but it could also increase pest pressure in your garden.  If you don’t plan to remove crop residue and don’t plan to till, then keep an eye out for what could be hiding in your garden.

False Potato Beetle:  An Overlooked, Destructive Pest of Eggplant

False Potato Beetle:  An Overlooked, Destructive Pest of Eggplant

August is awful.  Its heat makes one miss the relative cool of July.  Its rain is so sporadic that it invokes nostalgia for the rainy afternoons of early summer.  But if there is a silver lining in August for gardeners, it is the simplicity that it brings.  The weaker spring crops, tomatoes, squash and the rest, are all gone now, destroyed or rendered fruitless by insects, disease, and heat.  This leaves only the hardened, usually pest and disease-free survivors Okra, Pepper, Sweet Potato and Eggplant.  I say usually because, this year, my eggplant bed is under attack by a new-to-me pest, the False Potato Beetle!

I’ve dealt with Colorado Potato Beetles (CPB) before.  Those orangish, black-striped terrors often attack my spring potato crops and occasionally bother early tomatoes.  However, I’ve never seen them in late summer on Eggplant.  This raised suspicion.  Also, I spotted unusual, round, whitish purple creatures munching on leaves from the same plants; these appeared to be the larval stage of the unidentified beetle. A little digging led me to identify these garden pests as the lesser known, lookalike cousin of CPB, the False Potato Beetle.

False Potato Beetle munching on an Eggplant leaf in the author’s garden.

False Potato Beetle (FPB) looks nearly identical to its cousin in the adult stage.  They are similarly shaped and colored, though a close look reveals subtle differences between species.  While both have yellowish-orange heads and pale-yellow backs with dark stripes, the FPB’s back is slightly lighter hued, more of a whitish, cream color.  Also, the CPB’s underside and legs are a very dark orange to brown, with the False Potato Beetle having lighter colored legs and underside.  If you’re saying, “These old eyes will never be able to tell the difference, County Agent.  Cream and light-yellow look the same to me.”, I get it.  Fortunately for those of us with poor vision, the larval stage (babies) of the two beetles looks very different and is the key to correct ID!  FPB larvae are larger and have a whitish coloration.  CPB larvae, in contrast, are a similar burnt orange color to the adult beetle.  I promise, the difference is very distinguishable!

False Potato Beetle is considered a minor garden and agronomic pest as they typically only bother Eggplant, and they don’t usually destroy entire plants.  However, if you get a FPB outbreak in your Eggplant garden, they can still be pretty destructive.  These beetles feed in the same manner as caterpillar pests, chewing away entire sections of leaves and stems.  Unchecked infestations can defoliate entire sections of plants.  So, if you find these little beetles eating away at your eggplant garden, what can you do?

False Potato Beetle larvae. Photo courtesy of the author.

First, if you scout regularly, you’ll notice the beetles and their larvae in relatively small numbers before outbreaks become widespread.  I had pretty good success this year just catching infestations early and picking off the beetles I saw and squishing them.  Continue scouting and squishing for a few days and pretty soon,  the population is reduced to a manageable level.  However, if squishing makes you squeamish, you also have some common pesticide options at your disposal.  I normally encourage clients to start their chemical pest control strategy with “softer” products like Pyganic, a pyrethrin make from an extract from the Chrysanthemum plant.  Pyganic works great but is a little harder to find; you may have to order online or ask your local retailer if they can get it for you.  If you are unable to find Pyganic or it doesn’t perform for you, the old standby products with carbaryl or pyrethroids (Sevin, Ortho Bug-B-Gone, and others) also work well.

False Potato Beetle can be a late summer garden pain, but with regular scouting, proper insect ID, lots of squishing, and maybe a timely pesticide application or two, you should be able to continue to harvest eggplant deep into fall!  If you have FPB in your garden or have another horticultural question, give your local UF/IFAS County Extension office a call!  Happy Gardening!

How to Store Leftover Seeds from the Summer Garden

How to Store Leftover Seeds from the Summer Garden

I enjoy starting my garden from seeds.  Ordering seed opens so many more options relative to the limited old-fashioned seed and transplant selections that line garden shelves. Picking newer, improved varieties has several other advantages as well, including increased disease resistance, earlier fruiting, unusually colored/shaped fruit, and generally more vigorous plants.  One of the most exciting days of the year in my house is when the cardboard box full of the season’s seed packets comes in the mail!  However, I garden exclusively in small, 4’x8’ raised beds and only need a couple of plants of each veggie variety to fill the fridge with fruit; meaning I always have leftover seeds in the packets!  In the past, I’ve thrown the excess seed away and chalked it up to the cost of gardening in small spaces, but this spring, as seeds became somewhat hard to come by and several of the varieties I normally grow were out of stock, I started saving and storing my leftover seed packets for future seasons to ensure I have what I want!  You can save and store seeds too, here’s how.

Cauliflower seed waiting for the fall garden in the author’s refrigerator.

Properly storing your leftover seeds is a relatively simple process.  While seed longevity definitely varies somewhat according to species, regardless of how they are treated by you, remembering the following few tips can help improve the stored seeds’ viability and vigor for the next season.

  • Store Cool. Seeds like to be stored in a refrigerator around 40 degrees F.  Seeds stored warmer, near room temperature, or colder, as in a freezer, will decline much more rapidly than those in the fridge.
  • Keep it Dry. Humidity or moisture in the seed storage area is a sure way to reduce the shelf life of seeds.  Store dry in plastic bags or glass containers and add a dessicant.  Dessicants help keep storage containers dry and can be found for around $1 each from various online purveyors, making them a cheap insurance policy for your home seed bank!
  • Don’t Store Pelleted Seed. These days, you can buy pelleted seed for many of the smaller seeded vegetable varieties, like lettuce and carrots.  The pelleting process and materials used, while making it easier for old eyes and those of us with fumbling fingers to plant, reduces seed longevity.  Do your best to plant all the pelleted seed you purchase.  If you store pelleted seed, don’t say you weren’t warned when next season’s germination is poor!
  • Plant All Stored Seed the Next Season if Possible. Remember, that while most non-pelleted vegetable species’ seed can remain viable in storage for more than a year, it’s best to only store seeds until the next season and use them up.  Regardless of how well you store them, seed germination percentage (how many in the lot will sprout when planted) and vigor (how strong the germinating seedlings are) decline in direct proportion to time spent in storage.
  • Plant Old Seed Heavy. As germination rates in storage may have declined, it’s best to plant stored seed a little thicker than you normally might.  If you need a squash plant in a certain spot, instead of just planting one seed, put three or four in the hole to ensure you get a plant.  You can always thin extras later, but time lost replanting cannot be regained.

By following these few simple tips, you can waste a lot less seed and ensure that you have what you want to plant for the following year!  As always, if you have any questions about saving and storing seed or any other agriculture or horticultural topic, please contact us at the UF/IFAS Calhoun County Extension Office.  Happy Gardening!

The following resources were used as references when writing this piece and may prove helpful to you also, check them out:

  • Johnny’s Selected Seeds Seed Storage Guide:  https://www.johnnyseeds.com/growers-library/tools-supplies/seed-storage-guide.html
  • Seeding the Garden EDIS Publication: https://edis.ifas.ufl.edu/vh026#:~:text=Storing%20Leftover%20Seeds,better%20than%20in%20the%20refrigerator.

 

 

Armyworms Attacking Your Garden?

Armyworms Attacking Your Garden?

It’s been a challenging spring in this guy’s garden!  Despite getting the normal early start required for successful gardening in Florida, I’ve been affected by Bacterial Leaf Spot stunting my tomatoes, cutworms that reduced my watermelon plantings by half, and an eternal test of my patience in the form of a dog that seems to think my raised beds are merely a shortcut to a destination further out in the yard.  My latest adversary is the most potentially destructive yet, an outbreak of Southern Armyworm (Spodoptera eridania).

Early Southern Armyworm damage on Okra seedlings. Photo courtesy of the author.

Unlike some serious garden pests that wait until the heat of summer to emerge, Southern Armyworms begin appearing in spring gardens around the end of April.  Adult moths can survive mildly cold weather and venture into the Panhandle as soon as warmer spring weather arrives.   Once the adult moths arrive, egg masses are then laid on the undersides of leaves and hatch in a little under a week.  Once loosed upon the world, Southern Armyworm larvae (caterpillars) become indiscriminate, voracious feeders and congregate in extremely large numbers, allowing them to destroy small, developing garden vegetable plants in a manner of days.  Young larvae feed on the undersides of leaves and leave little but a skeleton.  As larvae grow larger, they become solitary and begin to bore into fruit.  Once they’ve eaten the good stuff (leaves and fruit), large larvae turn to branches and even plant stems!

Southern Armyworm larvae feeding on Okra leaves. Photo courtesy of the author.

The good news for gardeners is that Southern Armyworm, and most other caterpillar pests, are easily controlled if outbreaks are caught early.   Scouting is critical for early detection and good control.  Armyworm damage generally appears from above as brownish-gray sections of affected leaves with a yellowish ring surrounding these sections, this ring indicates the current feeding zone.  Affected areas will appear transparent and “lacy” due to the skeletonizing effects of larval feeding.  If you see leaves that look “off” in the manner just described, check underneath for the presence of a horde of tiny greenish worms.

If found in this early stage, an application of Bacillus thuringiensis (Bt), a biological pesticide utilizing a bacterium destructive to caterpillars, is extremely effective.  Bt has to be ingested by caterpillars with leaf tissue to work; thorough coverage of leaf surfaces is critical for maximum control.  I generally follow up with a sequential application of Bt a day later to ensure that I achieved good coverage of the plant surfaces and, therefore, good control.  Unfortunately, Bt is much less effective on older larvae.  Infestations not caught early require harsher chemistries like carbamates, pyrethroids and organophosphates for adequate control.

Don’t let armyworms or other caterpillar pests destroy your garden, get out there daily and scout!  You have a short window for easy caterpillar control with a harmless to people, natural product, Bt.  Don’t waste it!

For more information about Southern Armyworm, other caterpillar pests, Bt, or any other horticultural topic, please consult your local UF/IFAS Extension Agent.  Happy Gardening!

Tomato Leaves Spotty and Yellowing?  Could Be Bacterial Leaf Spot.

Tomato Leaves Spotty and Yellowing? Could Be Bacterial Leaf Spot.

Early BLS symptoms appear on lower leaves. Photo courtesy of the author.

Tomatoes are among the most notoriously difficult vegetable species to grow in Florida.  Even when you do everything right (choose disease resistant varieties, buy clean seed/healthy transplants, plant early, rotate crops, scout for insects, prune and support vines, etc), things can go wrong in a hurry.  Bacterial Leaf Spot (BLS) caused by the pathogen Xanthomomas perforans, is one of those things.  BLS often hitches a ride into gardens undetected on seed and transplants and presents itself as warm and humid weather arrives in late April/early May.  Outbreaks typically happen in concurrence with the frequent heavy rainstorms that accompany these months and quickly wreak havoc on tomato plants.

BLS occurrence, much worse in some springs than others, has exploded this year in home gardens.  First noticed on the plant’s lower leaves, BLS pathogens enter through natural openings in leaves called stomata, manifest as small, “water-soaked” leaf lesions and then develop within days into dark circular spots, sometimes surrounded by a yellow halo.  As conditions worsen, all these individual infections cause a general yellowing or “blighting” of entire leaves.  Though the issue begins on tomato leaves, BLS can affect all parts of the plant, including stems, flowers and fruit too! It’s at this point, when blighted leaves become obvious and lesion developing on flower stalks cause both flowers and small fruit to drop, that most home gardeners notice that something is up.

Advancing progression of BLS with “blighted” leaves. Photo courtesy of the author.

Unlike with many other pathogens, gardeners don’t have an abundance of options to control BLS.  However, taking the following preventative measures can reduce the pathogen’s impact and stave off disease progression until ripe fruit can be harvested.

  • Don’t irrigate overhead. Utilize drip/microirrigation or hand water beds and containers at soil level. This prevents the leaves from becoming wet; wet leaves become a perfect host for BLS.
  • Never work tomato plants when leaves are wet. No staking, pruning, tying, or anything else until plant tissue is dry.  Working wet tomato plants is an excellent way to spread bacteria!
  • Sanitize pruning tools often and wash hands after working infected plants.
  • Maintain airflow in plants by planting at correct spacing and thinning interior leaves as necessary to facilitate quicker drying of the plant.
  • Prune lower leaves to at least 12” from the soil’s surface to prevent disease transmission from soil to leaves through splashing water.
  • Remove infected leaves (when plants are dry!) to slow disease progression.
  • Rotate crops and destroy infected plants to prevent buildup of BLS organisms in soil.

    BLS lesions on tomato flowers. Photo courtesy of the author.

  • Preventative measures are best, but if your garden has a history of BLS and local weather forecasts call for warm/wet/humid weather, it is best to spray fungicides proactively to protect your crop. A weekly spray with a tank mixture of copper and mancozeb is effective at keeping BLS at bay.  This is the only chemical spray combination proven to be effective in controlling BLS.
  • Unlike many common tomato pathogens that can be reliably avoided through planting resistant cultivars like ‘Big Beef’, ‘Celebrity’ and others, no varieties are resistant to BLS.

While BLS is an extremely destructive pathogen of both home and commercially grown tomatoes, growers can lessen the disease’s effects by following the preventative measures outlined above and spraying with a copper/mancozeb mix if necessary.  Growing tomatoes this year hasn’t been easy, but it’s worth it to fight back and realize a harvest despite difficulties like BLS!

If bacteria have given you the blues or other garden issues are bringing you down, give your local UF/IFAS County Extension Agent a call!  We’re here to help you be successful in all your horticultural endeavors.   Happy gardening!