The LF procedure described in this article is applicable to large containers that are micro-irrigated. Micro-irrigation systems are well-suited for large containers in wide spacing arrangements compared to smaller container-grown plants in dense arrangements that are typically irrigated with overhead sprinklers. A typical micro-irrigation system delivers water directly to the container, often via a spray-stake placed near the container wall spraying inward (Fig. 1). Flow rates for spray stakes can range from 5-16 gallons/hour. For a trade 15-gallon container that has a diameter of 17 inches, this is equal to applying 5-16 inches/hour. When compared with sprinkler or overhead systems that apply water at 0.3-0.5 inch/hour, you can see why it might be easier to over-water a large, micro-irrigated container than one that is sprinkler-irrigated. This is why the LF test can play a critical role in scheduling irrigation for micro-irrigated crops.

Producers know plants need water to grow but how can water managers objectively determine how much irrigation water to apply? When a plant is grown in a container, the amount of water that is available to the plant is limited by the container volume and the container substrate’s capacity to retain water. The capacity of the container substrate to retain water is dependent on its components and their proportion. Ideally, a substrate will exhibit good water-holding properties while simultaneously providing adequate aeration for root growth. In the southeast United States, pine bark mixes are often the most popular substrates for producing plants in outdoor container nurseries. The confined volume of the container, even with a good substrate, typically requires daily irrigation if not several applications per day to ensure adequate moisture for the plant. The goal of the water manager is to apply enough water in these frequent applications to resupply the amount taken up by the plant without applying so much that excessive leachate results.

LF test and pizza pan setup

LF is defined as the amount of leachate divided by the amount of irrigation water applied to the container. Two measurements are needed for a LF test: the amount of leachate drained out of the container and the amount of water applied to the container.

The pizza pan comes into play on the first measurement. The pizza pan can be used to collect leachate from large containers (= trade 7-gallon) with micro-irrigation. A pizza pan is placed under the container and a hole punched near the rim of the pizza pan allows leachate to drain into a pan (e.g. lasagna pan) for measurement by weighing (Fig. 2). We recommend an aluminum pizza pan with a 1-inch high rim and a diameter at least as large as the top diameter of the container. Fortunately, restaurants serve up a variety of pizza sizes, so finding a 14-inch pan for trade 7-gallon containers and a 17-inch pan for trade 15-gal containers is not a problem (e.g. American Metalcraft ADEP17, 17 inches x 1 inch Standard Weight Aluminum Tapered / Nesting;www.webstaurantstore.com ). We make the drainage hole in the pizza pan by first drilling a one-eighth inch pilot hole about one-half inch from the pizza pan’s rim. We then insert the pointed end of a plumb bob into the pilot hole and hammer it to create a one-half inch hole. The punch creates a small funnel underneath the pizza pan which helps with draining. The pizza pan is placed on top of two 1-foot-long pieces of lumber (4x4 inches) to allow leachate to be collected underneath (Fig. 3). If needed, slope to improve drainage can be created with shims or small pieces of wood or bamboo. The pizza pan set up is left in the field so that leachate monitoring can be routinely conducted.

The second measurement needed for the LF test is the amount of water applied. For this, we insert an adjacent spray stake emitter into a 5-gallon pail with a one-half inch wide notch cut into the rim of the pail so that the spray stake tubing will not be crimped with the lid. After irrigation, the amount of water in the pail is determined by weighing. The spray stake emitter can be closed and left in the pail between LF tests to facilitate routine testing.

Routine LF testing and irrigation adjustment

We recommend at least three or four pizza pan setups per irrigation zone to account for plant and irrigation variability. Keep in mind the results from these three or four LF test containers will be determining the irrigation needs of the entire irrigation zone. To be conservative, include larger plants and/or border plants that may have relatively high irrigation requirements. Pizza pan setups placed near the borders of the irrigated area will decrease testing time. Because the LF test is simply a snapshot in time, LF testing should be conducted on days with normal weather and as frequently as possible. We found that once every 24 weeks is fine once you have established a good pattern of LF results. In general, frequency of LF testing should be higher during spring and summer months when potential evapotranspiration rates are increasing with warmer and longer days than in late fall and winter months when growth and water use slow down. If water is applied more than once a day, then leachate can be collected over all irrigation cycles during a 24-hour period. It is noteworthy that measuring leachate and amount applied for each cycle, while more work, gives an indication of how uniform the irrigation needs are from one cycle to the other.

Table 1 shows the results of a hypothetical LF test. The average LF of the four test plants was 42%. If the target LF is 25%, we know that the 6-minute run time was too long for that particular day. Using the equation that appears on this page, we can calculate an adjusted run time that would theoretically give us an LF of 25% under the same environmental conditions.

For the example in Table 1, the adjusted run time was 4.6 minutes. If your irrigation controller can only be programmed to the nearest minute, it would generally be preferable to round up and be more conservative. For example, if you rounded 4.6 minutes down to 4 minutes, the expected LF would be 13% instead of 25%. On the other hand, if you rounded up to 5 minutes, the expected LF would be 31%. Our experience is that a target of 13% LF is too low for many micro-irrigation systems so that the adjusted run time of 5 minutes would be preferable despite a slightly higher target LF. In general, we suggest a target LF of 25% for micro-irrigation production until experience indicates otherwise.

The pizza pan procedure for LF testing can help container nurseries monitor and maintain irrigation efficiency when producing plants in large containers with micro-irrigation. Based on results from seven trials conducted at three nurseries, average water use was decreased by 39% when using LF-directed irrigation versus the nursery’s traditional irrigation practice. We believe implementing a LF testing program using the pizza pan procedure can promote profitable plant growth and quality with less water. (Part one of a two-part series.)

It’s common knowledge that certain bacteria can make people sick, but did you know that bacteria can cause plant diseases as well? They most certainly do. The first bacterial pathogen to be identified was anthrax, a disease affecting sheep and cattle in 1876. Shortly after that, the first bacterial plant disease was confirmed – fire blight on apples and pears.

Fire blight is likely native to North America and has colonized most of the U.S. and Canada. While outbreaks are irregular, reports of devastation to apple, pear and other hosts were widespread in 2018, particularly in the Western U.S. Colorado, Washington and California experienced extended favorable weather conditions, and fire blight flourished. Fire blight is very difficult to control once established and can destroy entire orchards in a single season, if conditions are just right.

Infected plant tissue cannot be cured. This is partly due to the fact that fire blight infections extend up to 2-3 feet in wood beyond any visual signs and symptoms. Infected tissue can (and should) be removed and destroyed and clean plant tissue can be protected, but it is likely the tree will harbor the bacteria indefinitely. Disease management, as opposed to control, is key with fire blight.

If you’ve spent any significant length of time with a plant pathologist, you might have heard the phrase “disease triangle.” It’s a model to help visualize how interactions between the plant, environment and a pathogen can result in disease development. For example, if a susceptible host is present (such as Snowdrift crabapple), but the pathogen (in this case a bacterium) is not present or active, then fire blight won’t be a problem. Likewise, if the environment is not conducive to disease (such as hot, dry weather), then fire blight won’t be an issue then either.

Altering one or more of these three factors can impact fire blight development in a positive way for the grower.

Environment

Fire blight depends on favorable weather conditions associated with most springs: namely warm weather (between 65-85°F) accompanied by intermittent rains or high humidity. Throw in a little hailstorm that damages tender shoots, leaving open wounds ideal for pathogen entry, and the environment is prime for infection. While ambient temperatures cannot be altered, humidity can be lowered with techniques such as pruning and weed management. These practices increase airflow, which will help lower disease susceptibility.

Host

Fire blight infects over 200 different species in the Rosaceae family, including crab apples, pears, apples, Pyracantha and blackberry. Some cultivars are more susceptible than others; so, planting cultivars more tolerant of fire blight will help minimize overall damage. Beyond that, the way the host is managed can lower disease severity too. Fire blight prefers succulent growth; therefore, avoid actions that encourage new, vigorous growth, such as excessive nitrogen fertilization, high soil moisture and aggressive pruning. These are all ways to manage the host to slow disease.

Pathogen

In the case of fire blight, the vertex on the disease triangle is the toughest. Most of the plant diseases we know are caused by fungi, which tend to be easier to control with fungicides. Plant diseases not caused by fungi, however, pose a much greater challenge in terms of control. Humans and animals often rely on antibiotics for bacterial disease control and in some situations, antibiotics are used in agriculture, such as citrus greening in oranges. Nursery production and landscape management situations are far less suitable for antibiotic use; so, other control strategies are needed. Copper sprays are somewhat effective against the bacterium, especially to protect new, clean growth, but efficacy is limited under high disease pressure.

Finally, removing the pathogen itself can help reduce inoculum in subsequent growing seasons. Since the pathogen resides in infected plants, cankered tissue should be removed in winter months, when the pathogen is not active, and then destroyed. When removing a cankered branch, find the lowest part of the canker, trace the branch to its point of attachment, and cut at the next branch juncture. In the case of large cankers on trunks, scrape down the bark around the canker to the cambium. Pay attention to wood color as it can be an indicator of infection. Wood directly underneath a canker is usually dead and turns a red color further out, eventually becoming red flecks. Beyond that, the tissue is healthy.

Fire blight is difficult to manage but not hopeless in most years. Management should focus on environment and host modifications as a means of reducing disease pressure. Cultural practices combined with mechanical strategies can help, but in some years (like 2018), almost nothing seems to help.

Brick walls and barbed wire enclose the greenery, but the plants are lush year-round, sustained by the toasty Huntsville heat and the people who live behind those walls and wire at the Texas Department of Criminal Justice Ellis Unit.

Langley goes by Scooter, in part to differentiate himself from his father, James Langley Sr., who first started the prison horticulture program Scooter runs today. When it began, Lee College was simply trying to figure out which trades could most often lead to careers post-release. Langley Sr. initially became the horticulture instructor by pitching the school on the variety of different jobs an inmate could get after their release. From working in a nursery to lawn care, that diversity in opportunity stuck out to Lee College and Langley Sr. was hired.

For more than 40 years, the Langley family has taught landscaping techniques to incarcerated students. Inmates who agree to take Scooter’s classes are in a classroom or working in the field Monday through Friday for six hours at a time, earning certificates as a horticulture technician and in landscape management. If they complete both – each one takes about six months of class and field work – students can enroll in further academics to earn an associate degree in science and horticulture or business through Lee College, which employs Langley and is still partnered with the prison facility today.

“It’s just like regular school. They’ve got to be there; they’ve got to do the assignments,” Langley says. “We have teachers that come in and teach the same curriculum, the same stuff that they do in the free world. It’s not a ‘give me’ kind of deal. They actually have to go to school.”

That education is not only therapeutic; it’s practical. Langley’s goal – and the goal of similar programs across the country – is to get these inmates a second chance at a career beyond prison walls.

A new life

After his release last May from the Noble Correctional Institution in Caldwell, Ohio, Charles Ellis decided he was going to start fresh.

With a close friend, Ellis started Backyard Detail, a two-man landscaping business. He had just completed three years in prison for his drug trafficking conviction, and he says he wanted to take ownership and be proud in something he created. He was released before he completed his facility’s horticulture course, but he did receive his Ohio Nursery and Landscape Association certification.

Ellis also knew what type of uphill battle he faced after his release. He says some people will never get another opportunity at a career after serving their time in prison. Maybe they had one bad night or made one bad decision that cost them a lifetime’s worth of chances. This is another big reason why he took matters into his own hands and started Backyard Detail.

“To go to a job interview and when they ask you if you have a felony, to have to say yes and to sit there and explain and to hope that somebody could look past that, it was a big fear of mine,” Ellis says. “People make mistakes… but I would like to see jobs actually look past that and see a person for who they are. Give them a chance.”

Robert Scott spent several years teaching horticulture and sustainability at a Midwest prison. Now, he’s the executive director of Cornell University’s Prison Education Program, which serves four prisons and roughly 200 incarcerated students.

Scott says reformed citizens who line up a job after their release are less likely to find themselves back in prison. Studying recidivism can be difficult because there are plenty of scenarios where somebody is reincarcerated based on parole violations that aren’t technically crimes. However, Scott says nuanced analyses show these programs (not just in the horticulture field) are effective at landing good jobs and encouraging social behaviors compared to those in prison who don’t participate in an educational program.

And while Scott never guarantees potential employers that a second chance employee will work out, he says many of them acknowledge their new opportunity and make the most of it.

“Who you were yesterday doesn’t determine who you will be today or tomorrow,” Scott says.

The second chance

Ohio Department of Rehabilitation and Corrections administrator William Eleby works in the office of reentry and enterprise development, helping connect potential employees with jobs before their release. He organizes interviews and has inmates upload their resumes to a computer database that goes live up to 90 days before their last day in prison.

Eleby says only inmates who exhibit good behavior are allowed to participate in programs like the facilities’ horticulture classes.

He assesses whether a hiring company would be a good match for the person leaving prison. If, for instance, the company is located near a lot of bars and the student went to prison with an alcohol problem, Eleby’s going to advise against hiring that particular employee. He’s also denied companies that don’t want previous offenders to really be a part of their team. If a company isn’t willing to give these employees a legitimate chance at contributing something meaningful, Eleby may turn the company away.

“If you hire someone that is a restored citizen, then they’re restored,” Eleby says. “We don’t need you to say, ‘Well, we’re going to put them in a corner. We’re going to separate them from other employees.’ That’s not a good fit for us and I don’t think that’s the right company that we want to have an agreement with.”

While many lawn care and landscaping companies are having trouble finding reliable employees to hire, those that are connecting with prisons may be uncovering a worker who’s not going to complain about his or her work circumstances. ODRC horticulture instructor David Brennan, also a contractor with Brennan’s Plants in Athens County, Ohio, says his students will often do the physical labor that others won’t.

“We don’t mind getting cold, hot, dirty,” Brennan says. “Sadly, the percentage of the population that wants to do that is 10%, if that. As a contractor, we have a very limited pool we can draw on.”

Brennan also says many of his students will later be appreciative of the second chance, and Eleby says some feel particularly loyal to the companies that afford them the opportunity at a career after they leave prison. Ellis says it was gratifying to have his own company – and freedom – after his release.

“It was something to be taken away from your entire life and your entire world, to be able to come out of that and say, ‘I can do this for myself,’” Ellis says. “It means a lot. It made my life different.”

Good for the soul

These prison horticulture programs aren’t just about lining up jobs for convicts – they’re also about establishing the right path to recovery. The Insight Garden Program is largely based in California, and Executive Director Beth Waitkus has placed her program into several facilities on the West Coast and another in Indiana.

Insight Garden places an emphasis on the therapeutic element of the program, liberating the incarcerated by allowing them to design and nurture their own gardens. What’s most important to Waitkus is that her program’s students feel like they can take control of their own reformation and have a spot outside that allows them to express creativity and take pride in what they create. Their year-long curriculum covers environmental literacy in the first semester, then follows up with permaculture gardening, leadership and reentering society.

“People learn to respond rather than react, which is often the reason some of these people end up incarcerated,” Waitkus says. “They may (be) under stress and not think of their consequences before they happen. This whole curriculum is woven together with the idea of mindfulness.”

The Insight Garden Program is less traditional than horticulture programs in most prisons. There’s not as much of a classroom as there is a circle in which students sit to hear facilitated discussions. They ask students questions to see what they think rather than tell them what they need to know. They spend a lot of time meditating and base their program on action-based learning, including art, skits and other presentations. The focus is on themselves, not their career.

“Gardening is the metaphor,” Waitkus says. “How do you garden yourself? How do you weed out the things that no longer serve you?”

But even for programs that are more traditional, the byproduct of learning about horticulture is treatment. Langley’s program in Texas is based on Christian ministry and emphasizes the importance of helping others in their therapeutic garden. Scott mentions the profound importance of watching the incarcerated accept responsibility for their career out of prison. And in Ohio, Brennan says working out in the field allows for restoration that can’t be taught in a classroom.

“Correction is the bars. Correction is the order,” Brennan says. “But (this is) rehabilitation. We are taking people who have the desire, who want the job to go out, get a job, and turn away from a life in prison.”

Getting involved

Eleby recommends that companies reach out directly to prison facilities if they’re interested in hiring who he calls “reformed citizens.” Employers should define what type of worker they’re seeking and what kinds of previous history would not be acceptable at their company. For example, some companies may be willing to take on somebody who went to prison for drug possession but not someone who was convicted of stealing from a past employer.

And for companies interested in aiding the programs by volunteering instruction or resources, Eleby says reaching out and asking questions about that facility’s specific horticulture programs will help. Often, it’s beneficial for both potential employers and inmates to connect while they’re still serving out their time in prison. Eleby says he also educates companies on how convictions work, which he hopes eliminates potential stereotypes. Still, he also recognizes that sometimes, it’s best for companies to meet these people firsthand.

Additionally, Eleby says he can’t guarantee one of his students will work out, but he advises each of them to not blow their second chance. Any slipups could cost not only themselves but others dearly.

“You don’t want a company or a business to have a bad taste in their mouth because of your selfishness,” Eleby tells students. “You’re representing every restored citizen and every offender regardless, because others will be judged based on their interactions or relationship with you.”

Langley says that in the 11 years he’s served as an instructor in the horticulture program, he’s heard from several former students who have gone on to establish better lives. Dozens have lined up jobs or started their own successful companies, and Langley says recidivism with the horticulture program is the lowest among other trade programs Lee College offers inmates. Maybe students saved up to buy a new house or car, or they earned promotions at the companies they started with after their release. Those calls, Langley says, are the most rewarding part of the job.

“A lot of these guys have never had an actual career, an actual full-time job,” Langley says. “That’s why they’re trying to find these trades that sound interesting to them, so that when they get out, they can better themselves, better their family, and give back to society.”

The author is assistant editor of sister publication Lawn & Landscape magazine.

The box tree moth, Cydalima perspectalis, is native to China, Korea and Japan, and was discovered in Europe in 2007. The insect has spread profusely and is now present in over 30 countries. How did this insect get to Europe from China? It has been suggested that the movement of infested boxwood plants from China through the nursery trade may be responsible for the introduction of the box tree moth into Europe. In 2018, the box tree moth was detected in Ontario, Canada, which is the first detection of this insect in North America. Again, the movement of infested boxwood plants may be how the insect arrived in North America.

The box tree moth is known to feed exclusively on boxwoods, but the insect will feed on many boxwood species and cultivars. Therefore, because boxwoods are widely grown in nurseries and incorporated into landscapes throughout the United States, the potential economic impact of this insect could be substantial.

During a trip to the Netherlands in May 2019, I was able to observe, first-hand, the destructive nature of this insect pest feeding on the common boxwood, Buxus sempervirens. It was striking the extent of the damage in localized areas—with complete defoliation. Consequently, due to the potential for the box tree moth to ruin the aesthetic value of boxwoods in landscapes; people may start using plastic boxwoods.

Biology and damage

Mature larvae are about a 1/2-inch long, dark green on top, with dark stripes that extend down the sides of the body. The larvae have black heads, hairs protruding from the sides of the body and two black spots on each abdominal segment. They may be difficult to see because they hide during the day within the plant canopy. Young larvae feed on the lower leaf surfaces whereas older larvae feed inside loose strands of webbing and skeletonized leaves with only the mid-ribs remaining, which causes leaves to turn brown. The extensive webbing is generally filled with frass and cast skins and is very apparent on infested plants.

In addition to feeding on leaves, larvae will also feed on the bark, which can kill a boxwood plant. The larvae undergo five to seven instars and then pupate within the canopy of a boxwood plant. Adult moths emerge from pupae and live approximately two weeks. Box tree moth overwinters as a larva in a cocoon between leaves that are tightly bound by silk. There may be two to four generations per year in Europe.

Management

There are no known natural enemies (e.g. parasitoids and predators), and even birds and animals will not feed on box tree moth caterpillars because they harbor an alkaloid toxin that protects them from predation.

Insecticides such as pyrethroids, spinosad, chlorantraniliprole and Bacillus thuringiensis subsp. kurstaki may be effective against the box tree moth. However, timing of application is important, as well as thorough coverage of all plant parts. Physical removal by hand picking the larvae has been suggested as an option to reduce damage from the box tree moth; however, this can be time consuming and expensive.

It is important that we do the best we can, from a regulatory standpoint, to prevent the box tree moth from entering the United States. If not, then we will be dealing with another invasive insect pest on a plant that is extensively grown in nurseries and planted in landscapes throughout North America.

About the author: Raymond A. Cloyd is a professor and extension specialist in Horticultural Entomology/Plant Protection with the Department of Entomology at Kansas State University. rcloyd@ksu.edu