Center for Urban Agriculture – Page 33 – Empowering Georgia through UGA Extension

Crop Rotation in the Georgia Community Garden

November 30, 2015March 25, 2015 by Becky Griffin

Crop rotation is a huge part of integrated pest management (IPM) in Georgia vegetable production. It is an inexpensive tool in disease and nematode management. Correctly using crop rotation can cut down on pesticide use and result in healthier plants. Growing Vegetables Organically has some great information on this type of IPM.

As we are all planning our warm-season gardens crop rotation is something to consider. However, it is a whole lot easier to rotate crops around a 3 acre farm than it is to move them around a 32 square foot garden plot. How do we practice crop rotation in the community garden? It is even necessary?

Crop rotation has been around for centuries. Simply it is changing what is planted in a particular area each year. Planting the same crop year after year in the same location causes disease pathogens to build up and become a real problem. Rotating crops helps break this disease cycle. Also, since different crops use varying amounts of plant nutrients, crop rotation is a wise use of the nutrition in your soil.

Plants can be divided into families. Learn those plant groupings because many pathogens infect crops in the same families. The basic rule of crop rotation is:

Don’t plant crops from the same plant family in the same place every year.

Crop families:

Onion family (Alliaceae): chives, onions, garlic

Cole family (Brassicaceae): lettuce, collards, cabbage, broccoli, spinach

Squash family (Cucurbitaceae): pumpkins, watermelon, squash, cantaloupe

Bean family (Fabaceae): beans, peas

Tomato family (Solanaceae): tomatoes, peppers, eggplant

Since tomatoes and peppers are in the same family (Solanaceae), don’t plant tomatoes where you have been growing peppers. And, don’t follow squash with pumpkins (same Cucurbitaceae family). Many farmers follow a four year or even longer rotation plan. Their lettuce won’t see the same piece of soil for several years. This helps lower disease pressure and cuts down on fungicide use. Many Master Gardeners usually try for a three year rotation for a large garden area.

We know that crop rotation works to help create healthier plants but how does that translate in a Georgia community garden plot?

The best way is for the community gardener to choose plants from different families each year. This isn’t always practical. A gardener wants to grow what his/her family likes to eat. That may mean beans every year. The #1 vegetable grown in community gardens is tomatoes – year after year!

So, maybe you work with your fellow community gardeners and rotate who grows tomatoes and you all agree to share the tomato harvest. This may not always work, either. Some gardeners want lots of tomatoes every year.

Move your pole beans to the other side of the plot this year. Buy your tomatoes from the farmers market this year and try growing squash. Better yet, try growing and eating something entirely new.

An old fashion mattock may be your only tool for some modified rotation in your community garden plots. — An old fashioned mattock may be your only tool for some modified rotation in your community garden plots.

At the very least Bob Westerfield, UGA vegetable specialist, recommends turning your soil over. Dig deeply bringing up soil that hasn’t been exposed to the sun. Go as deep as you are able. In a small way you are not rotating your plants but rotating your soil. Your UGA Extension agent can help you come up with a plan for crop rotation that will work for your situation.

Happy Gardening!

Hourly weather forecasts from the National Weather Service

November 30, 2015March 23, 2015 by Willie Chance

Taken from the CASE website

The National Weather Service has a good graphical forecast tool for hourly weather variables available on their web sites. You can get instructions for how to get one for your location at http://www.srh.noaa.gov/oun/?n=hourlyweathergraph.

The forecast has a number of parameters to choose from, including temperature, wind, humidity, rain and other forms of precipitation, thunder, and a variety of fire weather variables that you might need if you plan to do controlled burns.

The output of the forecast depends on what parameters you pick but generally looks like the image below. The forecasts go out to six days from present, which should give you ample time to plan activities which are weather-dependent, like spraying pesticides or cutting hay.

Many of the private forecasting firms also provide hourly forecasts on their websites and using their apps on smartphones and tablets.

Soil Temperatures Important in the Georgia Vegetable Garden-A Guest Post by Sharon Dowdy

November 30, 2015March 18, 2015 by Becky Griffin

The air temperatures may be warm but the soil temperatures are still cool.

Georgia’s recent warm daytime temperatures have home gardeners itching to dig in the soil and plant summer crops. But University of Georgia experts warn gardeners not to be tempted. Soil temperatures are still far too low for seeds to germinate and transplants to survive.

“In Georgia, we may have a warm front come in one day and a cold front a few days later,” said Bob Westerfield, a consumer horticulturist with UGA Cooperative Extension. “It may hit 75 degrees outside, but the air temperature isn’t important when it comes to gardening – the soil temperature is.”

“That soil’s not ready for tomatoes. Summer crops need from 60 to 65 degrees.” he said.

Green beans can handle temperatures of about 55 degrees, but it is still not quite warm enough for them. If gardeners ignore his advice and seed their gardens, he says the seeds won’t germinate.

Gardeners who cannot resist the temptation can still plant cold season crops like asparagus, beets, broccoli, carrots, cauliflower, collards, kale, lettuce, mustard, onions, peas, potatoes, radish, spinach and turnips.

To track the soil temperatures in your area of the state, Westerfield recommends two different strategies. Buy a soil thermometer or use a meat thermometer to test the soil in your garden plot or rely on UGA’s Georgia Automated Environmental Monitoring Network at www.georgiaweather.net.

Soil temperatures “creep up slowly” and Georgia soils should be ready to sow in seed by early-to-mid

Use www.georgiaweather.net to check soil temperatures in your area. The current soil temperatures in Griffin are in the 40s.

April, Westerfield said.

“And don’t be swayed by the vegetable transplants lining the garden center shelves,” he said. “Just because plants are in the stores doesn’t mean it’s time to plant them.” Contact your local UGA Extension Agent for more information.

For more information on vegetable gardening in Georgia, see the UGA Extension publication, “Vegetable Gardening in Georgia”.

Sharon Dowdy is a news editor with the University of Georgia College of Agricultural and Environmental Sciences. Growing her own tomatoes has been beneficial for Sharon’s heart. She met her beau five years ago while buying tomato stakes at Home Depot.

Happy gardening!

Follow herbicide label to avoid killing landscape plants and trees

November 30, 2015March 17, 2015 by Willie Chance

Paul Pugliese is the agriculture & natural resources agent for the University of Georgia Extension office in Bartow County.

An herbicide designed to kill weeds in turfgrass can also kill neighboring trees and shrubs.

Herbicides in the phenoxy chemical class provide broadleaf weed control in lawns, pastures and hay forages. Some of the more common chemicals in this class include 2,4-D; MCPP; dicamba; clopyralid; and triclopyr.

Safe for animals but not always for trees and shrubs

These chemicals are considered very safe and leave very few toxicity concerns for animals. In fact, many of these herbicides are labeled for pasture use and allow for livestock to continue grazing without any restrictions.

Phenoxy herbicide damage to a willow oak tree. Image credit: Paul Pugliese.

However, pesticide labels should always be read and followed to determine if any special precautions should be taken for specific site uses.

Phenoxy herbicides provide selective weed control, which means they control many broadleaf weeds without causing damage to grass. Of course, each product is a little different and some are labeled for very specific turfgrass types, depending on their tolerance.

The label should be checked for application to a specific lawn type (tall fescue, bermudagrass, zoysiagrass, etc.). If the turfgrass isn’t on the label, don’t assume the herbicide can be applied to all lawns.

Unfortunately, phenoxy herbicides don’t discriminate between dandelion weeds or any other broadleaf plants, including many trees and shrubs. So, it’s very important to take extra precautions when applying these herbicides near landscaped areas with ornamental plants.

Wind and rain can spread herbicides

Consider the potential for drift damage to nearby plants and avoid spraying herbicides on a windy day. There is also the potential for movement of these herbicides through runoff and leaching in the soil. This is why the product label usually warns against spraying within the root zone of trees and shrubs and never exceeding the maximum application rates listed on the label.

Many homeowners and landscapers often overlook these label precautions. The information that is contained on the label can seem somewhat vague to inexperienced applicators.

The biggest misconception concerns where the root zone of a tree or shrub exists. The roots of mature trees and shrubs actually extend well beyond the drip line of the canopy. Research shows that absorption roots may extend as much as two to three times the canopy width.

Consider spot-spraying to target individual weeds rather than broadcasting applications across the entire lawn. And never exceed the labeled rate.

In landscapes that contain mature trees and shrubs, phenoxy herbicides may not be the best choice for weed control. These herbicides may be best reserved for wide-open spaces such as athletic fields, parks and pastures where tree roots are at a safe distance.

The high potential for herbicide damage to trees is another great reason to protect tree roots by providing a mulch zone that extends well beyond the drip line of the canopy. If you’re not trying to grow a manicured lawn underneath a tree, then there is no reason to apply phenoxy herbicides there for weed control.

Use the right herbicide for the job

Another way to avoid potential damage is to rely less on phenoxy herbicides. Other classes of herbicides have less potential to affect the roots of nearby trees and shrubs. Take the time to identify your weeds and choose a more selective herbicide rather than combination products that usually contain multiple chemicals in the phenoxy class.

Many pre-emergent herbicides can prevent weed problems in lawns. The key is to apply them at the correct time in spring and fall. Applying too early or too late often provides inadequate weed control and requires additional herbicide applications. Rotating pre-emergent herbicide classes will avoid the potential for resistant weeds. Also, be sure to apply water to the area according to the pre-emergent herbicide’s label to activate it in the soil.

For more information about the effects of phenoxy herbicides on landscape trees and shrubs, view the UGA Center for Urban Agriculture webinar at archive.gaurbanag.org/webinars. For assistance with weed identification and specific herbicide recommendations, contact your local UGA Extension office at 1-800-ASK-UGA1 or visit www.Georgiaturf.com.

You can also watch an online webinar on Effects of Phenoxy Herbicides on Landscape Trees and Shrubs by Paul Pugliese.

Is it okay to apply herbicides to lawns during green up?

November 30, 2015March 17, 2015 by Willie Chance

Tim R. Murphy. Retired UGA Weed Scientist

Rank growth of winter annual weeds occurs at the same time that warm-season turfgrasses begin to green-up, or emerge from winter dormancy. These weeds compete with the turfgrass for soil moisture, nutrients, growing space, but most importantly for sunlight. Warm- season turfgrasses, with the exception of St. Augustinegrass, are not highly shade tolerant. Thick mats of winter weeds will shade the turfgrass at a time that root carbohydrates are being exhausted by the green-up process. Additionally, thick mats of winter weeds shade the turfgrass and decrease photosynthesis. The net result is a weakened, or less dense stand of turfgrass, that is readily infested by summer annuals such as crabgrass.

Purple Deadnettle, Robert Vidéki, Doronicum Kft. Bugwood.org

Preemergence herbicides

Research has shown that the preemergence herbicides, such as Balan, TeamPro, Surflan, XL, Ronstar and many others, that are used for summer annual grass control do not significantly affect the spring green-up of labeled warm-season turfgrasses. A possible exception is Pennant (metolachlor). There have been some significant delays in the green-up of hybrid bermudagrass with Pennant applications to dormant turf.

Postemergence herbicides

The situation with postemergence herbicides is dramatically different. Most postemergence herbicides will slightly delay the early spring growth of warm-season turfgrasses. These delays can range from a few days to a few weeks.

In the event of an overdose (an extremely high rate), delays in spring green-up can occur for a longer period of time. Usually, the turfgrass will completely recover within two to six weeks with proper cultural management.

With the exception of Image, most postemergence herbicides can safely be used during green-up. Some slight delay in green-up may be noted; however, this effect can be lessened by:

Using the lowest recommended rate
Insuring that the application equipment is properly calibrated
Using spot treatments
Following all recommended cultural practices, fertility, irrigation, etc. to promote rapid spring growth.

The use of postemergence herbicides should be avoided during the spring green-up of turfgrasses that have been poorly managed, or that are experiencing winter injury problems. Properly maintained, healthy, vigorous turfgrasses are more tolerant to postemergence herbicides than turfgrasses that have not been properly maintained or are suffering from winter injury.

Some postemergence herbicides state on the label “Do not apply during spring green-up.” Obviously, these products should not be used at this time of year. However, the use of other postemergence herbicides is warranted if there is a severe weed infestation on properly maintained turfgrasses. The slight delay in green-up from the use of these herbicides is more than compensated for by the removal of competition that dense mats of weeds exert on the turfgrass.

As always – read and follow all pesticide labeling directions!

Get updated on fire ant baiting

November 30, 2015March 15, 2015 by Willie Chance

Article written by Mike Merchant, Texas A&M Agrilife Extension Entomologist, in his blog Insects in the City

Fire ants remain the most prevalent outdoor ant pest in most areas of the southern U.S. Throughout the U.S. we estimate the annual cost of fire ant control at over $6 billion. But the cost of this pest goes far beyond measurable dollars. Fire ants reduce the recreational value of our parks and backyards, disrupt wildlife populations, and send thousands to emergency rooms each year from their painful stings.

So as we get ready to enter fire ant season, it may be a good time to bring yourself and your staff up to speed on fire ant control. Many people are surprised to learn that fire ants are not an especially difficult pest to manage, once the biology and control tools are understood.

One of the best places to learn about fire ant management is the eXtension fire ant website, a place where the best information about fire ant is assembled by Extension agencies throughout the South. This information was recently summarized and presented in an informative webinar by Dr. Fudd Graham, fire ant specialist with Auburn University. Dr. Graham focuses on fire ant biology and use of baits for fire ant control.

It’s worth knowing something about how fire ant baits work because they are the most economical, ecologically friendly, and effective control methods for fire ants. The webinar will provide you or your technician with an hour of training that should pay for itself many times over.

Mike Merchant is an entomology specialist for Texas AgriLife Extension. He works with pest management professionals, school facilities managers, extension volunteers, researchers and other extension professionals. His areas of specialty center on research on insects affecting man including spiders, scorpions, fire ants, termites and others. His program also focuses on training school maintenance professionals in principles of integrated pest management (IPM). His goal is to make schools healthier, cleaner places to study and live.

Sidney B Meadows scholarship application now available

November 30, 2015March 15, 2015 by Willie Chance

For more info visit the Sidney B Meadows Scholarship website

We invite you to apply or advise a horticultural student of the benefits of this scholarship. Scholarships are awarded, through a competitive process, administered by a selection committee based on academics, character, determination, probability of a career in horticulture, and financial need.

In 2014, twelve $1,500 scholarships were awarded, totaling $18,000. The number and amount of scholarships awarded each year is determined by the board of directors based on the fund’s income (interest and dividends) from the previous year.

Scholarship applications for the 2015 year a now available. Deadline for application is May 29th. Selections will be made by July 1, and recipients will be notified soon thereafter. Awards will be made July 22 in Atlanta during SNA2015.

Please refer to the eligibility requirements, and download the 2015 Application below, or call the Fund office at 678.813.1880 to receive an application via email attachment, fax or regular USPS mail.

Visit the Sidney B Meadows Scholarship website

Severe weather chances increase as we move into spring

November 30, 2015March 14, 2015 by Willie Chance

Taken from the CASE website

Now that spring is here and warmer, more humid air is entering the US, severe weather and tornado chances are increasing across the country. There is an excellent animation that shows how the region of severe weather occurrence moves around the country at the NOAA Storm Prediction Center. The area of most likely severe weather moves north and south with the area of greatest temperature contrast and most active storm track as the sun’s angle changes over time.

The Weather Channel has also provided a series of bar graphs which show the monthly probability of tornadoes for over 40 cities around the country (link). From the graphs you can see that the Southeast has a split severe weather season, with the major peak in spring and a secondary peak in late fall.

For answers to every question you can ask about tornadoes, check out the tornado FAQ from the Storm Prediction Center.

And make sure you have access to real-time severe weather warnings via smartphone app or NOAA weather radio, especially if you are working outside on high-risk days.

Cooking with Georgia Kale and Seth Freedman

November 30, 2015March 11, 2015 by Becky Griffin

Chef Seth Freedman is a Southern man with New York chef training. That can be the best of both worlds! He still cooks with his grandmother’s cast iron skillet but using advanced culinary techniques.

Owner of Forage and Flame, Seth specializes in catering for groups large and small. He enjoys educating people about cooking locally grown food. In addition to Forage and Flame, Seth is a partner at Peach Dish where you can order fresh ingredients with recipes and have them delivered to your home for preparation. And, Seth loves his greens!

Recently he shared a kale recipe at the Georgia Organics conference. For those of us who are not kale lovers, we were impressed. I asked Seth if I could share the recipe and tips and he happily said “YES!”.

Kale and Apple Salad

1 bunch of kale

2 TBSP apple cider vinegar

1/4 cup olive oil

2 tsp honey

2 apples (crisp and sweet)

salt and pepper to taste

1. Remove stalks from the kale and discard them. Wash leaves and slice them thinly.

Massaging the kale is the most important step in the recipe.

2. Dice apples into 1/4 inch cubes.

3. In a large bowl, mix vinegar with honey and ground pepper. Drizzle in the 1/4 cup of olive oil while whisking. Pour dressing into another container.

4. Add kale and a small sprinkle of salt to the large bowl. Using your clean, bare hands massage the kale with the dressing left on the sides of the bowl. Seth says to squeeze them so that you are actually bruising or breaking the greens a bit. Squeeze, mash, massage – really get in there. This helps take some of the bitterness out of the greens and is the secret to this recipe!

5. Pour the rest of the dressing over the kale and add the apple dices. Adjust seasoning, toss and serve.

Seth says that really any Georgia grown green will work in this recipe – mustard greens, collards – whatever you have growing in your garden plot. Remember the squeezing, mashing, massaging is the key!

Let us know if you prepare this recipe and what you think of it. If you would like to contact Seth you can reach him at seth@peachdish.com. Thanks again, Seth, for sharing your expertise!

Happy eating!

When do we expect the last frost?

November 30, 2015March 9, 2015 by Willie Chance

Taken from the CASE website and written by Pam Knox, University of Georgia Agricultural Climatologist

Now that March is upon us and the atmospheric pattern has shifted into something that is bringing more spring-like weather to the Southeast, it’s time to think about planting. And that means thinking about the last frost of the winter.

AgroClimate has a tool which shows the last frost date by county for the Southeast. The 50 percent map shows the average date for the last frost, while the 10 percent map shows the date that one in ten years will see a frost, and the 90 percent map shows the date for which in just one out of ten years the last frost will come early (or in other words, in 9 out of 10 years the last frost will come later than this date). The maps below show the dates for 32 F. You can find the tool athttp://agroclimate.org/tools/Freeze-Risk-Probabilities/.

If you need the information for a different temperature threshold, then a good source of information is the Southeast Regional Climate Center. You can go to their web page www.sercc.com and pick “Historical Climate Summaries” from the “Climate Data” menu at the top. Pick your station and then look for “Spring Freeze Probabilities” on the left menu. Here is the graphical output for Tifton, GA.

What this shows is that for Tifton, for a temperature of 32 F (orange line) at the 50th percentile (for the average date), the date is about March 10. You can click on the link for tabular data to get a table of numbers instead of the graph shown here. Keep in mind that this is for the period of record for the station, and that last dates for spring freeze have been trending earlier in the season in recent warm years. If you have a different source of freeze information that you like to use, please let us know!

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