Renewing your glass or replacing worn-out polyethylene coverings can increase production while recovering costs in a relatively short period of time.

Light is one of the key ingredients needed for plant growth. A rule of thumb is "1% increase in light is equal to 1% increase in plant growth." How can we increase light levels, especially on dark days in winter?

Studies have shown that greenhouse films and polycarbonate lose 2% or more of light transmittance due to ultraviolet rays each year. Depending on the location of the greenhouse, the accumulation of dust, dirt and air pollutants may also lead to reduced light. In some areas near major cities on the East Coast, Midwest, or West Coast, the annual decrease may be 5%. Industrial areas also tend to have greater concentrations of smoke (smog).

I recently visited the Freund Farm Market and Bakery in East Canaan, Connecticut, for an energy audit. Theresa Freund said that they have replaced the 7,200-square-foot gutter connected to the greenhouse with polycarbonate that has been used for 20 years. She found that this resulted in having to rework the factory's production plan because the increased light reduced the factory's production time in the spring by two to three weeks.

A simple calculation can be used to estimate the fuel saved by the reduced time when the greenhouse is not heated. Determine the number of heating days in a year. This can be calculated based on degree day data from any location in the world on the www.degreeday.net website. According to the research of Rutgers University, choose a temperature that is 50 degrees lower than the night working temperature and let the program calculate the number of days in degrees. Solar energy makes up the difference of 50. Divide the estimated gallons of oil or propane or natural gas ccf used in the greenhouse that year by the number of degrees to get the fuel usage/degree days. Based on the degree-day calculation, determine the number of degree-days during which heating is not required, and then multiply it by the fuel usage/degree-days. Then multiply by the fuel cost to get savings.

The Freund's Farm greenhouse used 3,880 gallons of propane in 2020 for 1,400 degree days, or 2.77 gallons per degree day. There were 400 degree days in the first two weeks of March, when the greenhouse did not have to be heated, which saved 1,108 gallons. At $3 per gallon of propane, the savings of not having to provide heat resulted in savings of approximately $3,324. This helps offset the cost of new glass. It also saves the labor required to maintain the plants for two weeks.

For inflatable greenhouses, it may be economical to replace the plastic every year. In summer, the light level is high enough, and reduced light may not affect plant growth. In late autumn, winter and early spring, this is the most concerned. Let us look at an example. The cost of replacing double-layer plastic on a 30' x 100' hoop house is approximately US$1,500 (plastic and labor costs are US$0.50/square foot x 3,000 square feet = US$1,500). At a wholesale price of US$3 per pound, the output of each tomato plant only needs to increase by 0.63 pounds to cover the cost of the new plastic. After installing new plastic, it is not uncommon for each plant to increase its yield by one pound or more.

Now that we have completed the simple upgrade of the greenhouse, let's look at some other areas that can increase the light of the plants.

John is an agricultural engineer, an emeritus extension professor at the University of Connecticut, and a regular contributor to greenhouse management. He is an author, consultant, and certified technical service provider who conducts greenhouse energy audits for the US Department of Agriculture grant program in New England. jbartok@rcn.com

The dark age does need dark plants. Learn which gloomy but fashionable breeds stand out from the crowd.

In the past few years, have you felt a bit black and blue? Me too. Therefore, I decided that "bruise" will be the appropriate color theme for the garden in 2022. "Bruise" has always been my favorite color combination, but now it feels particularly suitable. Black, blue, purple, and a bit of yellow-green are used for contrast and accuracy. Fortunately, some lovely black and blue perennials will enter the retail market in 2022.

Dark leaves often seem to be needed during dark periods. The trend of black leaf plants is not new, but we have seen it regain popularity in the past year or so, especially in the indoor plant market. Raven ZZ plants, Alocasia, Peperomia, Begonia and Ludisia discolor (Ludisia discolor) have caused a great sensation in indoor gardens. Drawing inspiration from indoor gardening trends, black leaves will also resonate with outdoor gardeners.

Consumers just want to find something different or unique to improve their living space and garden. Black or almost black leaves and flowers will definitely be different. Considering the number of new perennials that encourage gardeners to grow toward the dark side, I would say that the black leaves should be left in the sun for a while.

I did manage to participate in a business trip planned for the past two years, but it was not cancelled: AmericanHort's Cultivate '21 show. Although figuring out how to navigate a crowded convention center during the pandemic feels a bit weird (I suspect it's not just myself), I quickly walked through the trade show grounds; in particular, looking for new outstanding plant varieties.

Sedum'Back in Black': You can definitely take this autumn bloom to the dark side of the sunny garden. For most of the growing season, the nearly black leaves will create a sharp contrast in your garden, followed by the flowers with cream petals and bullseye red centers, forming a pink hue throughout the flower cluster. Give plants plenty of sunlight to preserve the rich and deep leaf color.

Hibiscus'Edge of the Night': Although the pink flowers are not technically suitable for my "bruise" color scheme, it is undeniable that the leaves of this new compact hardy hibiscus are close to black and very beautiful. The leaves are described as "dark", in stark contrast to the huge 8-inch rosy pink flowers. As the plant grows to only 3-3 ½ feet tall, this variety should also make a good container specimen. Of course, plenty of sunlight keeps the intensity of these beautiful flowers and leaves unchanged.

Geranium'Boom Chocolatta': As the name suggests, this gorgeous hybrid of Geranium has delicious dark bronze leaves and chocolate tones. But its combination with intense purple to blue flowers makes this plant firmly integrated into my bruising scheme. Although I believe this variety first entered the market a few years ago, this is the first time I have seen it. It is a new introduction to the Proven Winners Perennials program. Now, where I am gardening in Texas, due to our extreme heat and drought, I can't say that we have a lot of luck in growing griffins. But when planted here, they are best placed in a mottled shade garden. Of course I am willing, because it promises to be more "vibrant", try it in my tough Texas garden.

Schizachyrium scoparium'The Blues': This small blue stem has earned itself the coveted title of 2022 Perennial Plant of the Year, and for good reason. This tough, clumpy grass has the most elegant icy blue leaves, with red stems as the accent. As the temperature gets colder in autumn, each plant will grow its own "wounded" stem, providing a mix of colors from purple to blue to orange. The beauty of this blue stunner is that it thrives on poor soil and limited water. If you are willing to give up any additional TLC, it is an aquatic perennial that is easy to grow in sunny places.

Amsonia'String Theory': This compact cultivar blooms light blue to periwinkle, which looks like little stars sprinkled in the garden. If you are looking for a more compact, denser alternative to Amsonia hubrichtii, with the blooming ability of A. tabernaemontana'Storm Cloud','String Theory' is expected to be realized. It is also expected to provide dark green leaves throughout the season, rather than the chlorotic leaves that often occur in standard species. Only 18-22 inches tall, this compact blue beauty can be moved to the front of the frame.

If there is no bit of purple in the mix, any bruises will be incomplete. One of my favorite discoveries on Cultivate '21 is the new Cake Pops collection of tuberous verbena. Purple is clearly an excellent color. This is a species that is very comfortable in the harsh horticultural climate of Texas, but it may become a little beast. So, I am very happy to find these cute round compact cake bars in the container in the new variety section of the show. The compact, mound-like form lends them to the border and the front of the container-not to mention the hanging basket. Hey, the V.rigida hybrid may be one of the few things that can spend the Texas summer in a hanging basket without 24/7 irrigation. I'm here to find it. Well, I realized that as far as Zone 5 Mafia is concerned, this factory is annual. But for the entire southern half of the country, this species is happy to exist year after year.

Lest you worry, I have forgotten the disturbing yellow-green that usually produces a good luster. I encourage you to check out the new and interesting series of Jurassic ferns, all of which seem to offer yellow-green to yellow-green leaf colors, very Suitable for a sharp contrast in the shady garden.

My recommendation for 2022? Just make sure to keep a few bags of frozen peas on hand.

Check out some of the major headlines in the industry.

The All-America Trials (AAS) announced that Gloucester, Massachusetts has become the winning community for the 2021 American Bloom/All-America Trials (AIB/AAS) Show Garden Competition.

At the beginning of 2021, 20 AIB participating communities were given the opportunity to plant AAS display gardens. Twenty gardens were selected to celebrate the 20th anniversary of Bloom in the United States in 2021. Each community has obtained at least 12 varieties of AAS winners suitable for the region, and the community does not need to pay any fees.

Community gardens must be publicly displayed, and all plants are marked with variety names.

The National Greenhouse Manufacturers Association (NGMA) announced that Tim Lauer of Albert J. Lauer, Inc. in Farmington, Minnesota has been appointed as the new chairman of the NGMA board of directors. After Tom Vezdos stepped down, he assumed this role.

Lauer has more than 26 years of experience in the greenhouse industry. He is proud to be the third generation to inherit the footsteps of his father and grandfather. His grandfather founded Albert J. Lauer, Inc. in 1947; Tim, as the company's vice president, continues to design, manufacture, and build aluminum greenhouses for today's commercial growers, retail garden centers, and institutional markets. As a member of NGMA for many years, Tim attaches the greatest importance to opportunities to learn, discuss, collaborate and communicate with other business owners, engineers and designers.

According to the press release, Longwood Gardens has appointed Dr. Kate Santos as Director of Research and Conservation. She will lead "the organization's science-based activities to strategically promote excellence in research, conservation, land management, and ecology, and have an impact on the local, national, and global levels."

After joining Longwood, Santos has 15 years of experience in leading for-profit business functions in the horticulture sector. Recently, she founded Kate Santos LLC, a plant consulting company, to provide solutions for the world's most growth-focused horticulture companies.

Prior to this, Santos worked at Dümmen Orange for six years, where she served as North America Operations Director and Americas Supply Chain Regional Director, managing the leadership teams in North, Central and South America. Santos also spent time doing research at Costa Farms in Miami, Florida.

If done correctly, underground irrigation can be an effective method of watering greenhouse crops.

Watering greenhouse crops is arguably one of the most important tasks in any production facility. How and when to irrigate crops will affect plant growth and development, and ultimately affect the final plant quality.

Irrigation also affects other aspects of production, such as plant diseases and water and nutrient use efficiency. The way crops are watered also has a great impact on labor costs. There are many ways to irrigate greenhouse crops. This article will focus on subsurface irrigation and some tips and tricks or best management practices to keep in mind.

Overhead irrigation is the most common form of irrigation, in which water and nutrient solutions are delivered manually through hoses or automatically from spray bars.

Drip pipes or drip irrigators are also widely used to irrigate the surface of the substrate. Secondary irrigation is a technique in which water or nutrient solution is provided to the bottom of the container and absorbed or absorbed into the growing substrate by capillary action. There are many different ways to irrigate plants, including ebb and flow benches or Dutch pallets, flood floors or capillary mats.

Although these different underground irrigation systems vary in cost and longevity, providing options for any scale of production, the principles of using any underground irrigation system are the same for all these systems.

Why use underground irrigation to grow greenhouse crops? There are several advantages to using this method. First of all, underground irrigation can help reduce diseases, especially foliar diseases. High humidity and independent water promote diseases such as botrytis and powdery mildew. Overhead irrigation makes the leaves wet, by watering early in the day and allowing enough time to dry the leaves, and by using horizontal airflow (HAF) fans to promote drying. Through underground irrigation, the leaves will remain dry regardless of the irrigation. Sub-irrigation can also be more flexible in scheduling irrigation time-watering the crop later in the day will not run the risk of wet leaves entering at night.

In addition to minimizing foliar diseases, underground irrigation can also improve plant quality. As mentioned earlier, water or nutrient solution is absorbed by capillary action in the root zone until the substrate is saturated. Compared with overhead irrigation, no matter how wet or dry, the same or similar amount of water is applied to each container, underground irrigation allows the containers to absorb different amounts of water until they reach the same saturation level, thereby improving the uniformity of the entire container. crop.

Underground irrigation is also very flexible and can adapt to different crop spacings. Whether it is a shuttle tray of a 4-inch container placed in a pot, or an 8-inch poinsettia placed in an 18-inch center, it does not matter for underground irrigation. This flexibility makes switching between crops throughout the year seamless and easy, especially when compared to the use of droppers and emitters with a fixed pitch.

Finally, as with any form of automatic irrigation, for underground irrigation systems, labor savings are significant. By eliminating manual watering, underground irrigation allows hundreds to thousands of plants to be irrigated simultaneously, depending on the size of the underground irrigation area.

When using underground irrigation, no matter which system is used, some cultural practices must be carefully modified or monitored. First, the fertilizer concentration must be reduced. Regardless of whether it is water-soluble fertilizer or controlled-release fertilizer, less underground irrigation is required. Since the water moves upwards into the container by capillary action, there is almost no leaching during underground irrigation of crops.

Although this can be considered a good thing, especially in terms of improving the efficiency of water and nutrient use and avoiding unnecessary runoff, there is no chance to filter out the excess fertilizer salts from the container and reduce the conductivity. Using less fertilizer will help avoid the super-best substrate ECs and still provide sufficient nutrients for plant growth. How much should the fertilizer concentration be reduced? A good starting point is to reduce the concentration by 50% compared to the concentration used in overhead irrigation. If in doubt, choose less fertilization. It is always possible to provide plants with a higher concentration of water-soluble fertilizer (WSF) to increase the substrate EC in the irrigation system, but providing too much may be difficult to handle.

Another consideration for underground irrigation systems, especially those that capture and circulate water and nutrient solutions, is excess pesticide runoff, including plant growth regulators (PGR), pesticides, and fungicides. When these solutions are likely to be recaptured in the same reservoir where water and nutrient solutions are stored, the active ingredients can be absorbed in subsequent irrigation events. Ultimately, this can lead to unnecessary and/or excessive use of these chemicals. When spraying water on a container grown in an underground irrigation system, minimize the leaching of the pesticide solution from the container. Likewise, avoid excessive runoff from the canopy and application to the floor or workbench area.

Finally, sanitation should be a priority for any underground irrigation system. Although greenhouse hygiene is important for any operation, regardless of its irrigation system, it is of additional importance for underground irrigation systems where water and nutrient solutions are captured and reused. Diseases usually do not spread between plants through the transmission of underground irrigation systems, because the water is absorbed by the substrate and leaching does not occur. However, if pathogens enter the water through other means, such as infected plant material placed on a bench or floor, the infected water recycled and provided to the plants can cause the disease to spread rapidly.

Maximizing crop quality and minimizing labor is the common goal of any greenhouse grower. Regardless of your production scale, there is an underground irrigation strategy that suits your facility and budget. The best management practices outlined in this article help achieve the best results through underground irrigation systems.

Christopher is an associate professor of horticulture in the Department of Horticulture at Iowa State University. ccurrey@iastate.edu

Like any millennial generation, I have heard of FOMO (fear of missing out). But FORO? That is new to me.

Last week I attended AmericanHort’s first finished product factory meeting in Grand Rapids, Michigan. The result was a two-day (sometimes highly technical) in-depth study of all aspects of plant production while bringing them out of young plants (aka Liner) stage.

I don’t have enough space here to cover all the things that happened in the American Beer City-to be honest, it looks a bit like a ghost town due to COVID-but I can relay a few gold nuggets I picked up:

Locals and pollinator-friendly crops are still hot among plant buyers, and this situation is likely to continue until 2022.

If you invest enough greenhouse space to expand the scale of production, succulents can make incredible profits.

However, the other thing I still insist on is this new FORO concept for me, or fear of running out (selling plants). One grower briefly mentioned that we often focus too much on bottom-line sales and revenue and please every customer. Sometimes we act like selling out plants or varieties is the end of the world.

His point is, well, maybe it's not always that bad. Because it also confirms that you are growing the right type of plants and growing them in a way that customers are looking for time and time again.

And I don’t have to tell anyone here, this is usually half the battle (or maybe close to 33%?).

Bottom line: Don't let FORO influence your purchases this season. Trust your data and focus on plants that continue to sell out every season. This is a good thing!