High Tunnels and Season Extension

Have you ever wished you could start growing crops earlier, but our colder Virginia winters often keep you waiting until later in the Spring? With high tunnels, you can extend the growing season, both earlier in the spring, and later into the fall!

Photo by NRCS

What are High Tunnels?

High tunnels are unheated metal-framed structures covered with plastic that resemble greenhouses. High tunnels can protect crops from adverse weather conditions and allow for season extension earlier in the spring and later into the fall. This allows for crops to be grown outside of their normal growing seasons. This can give you a leg up at the market, providing you with earlier market-ready than your competitors, and can help you to harvest crops before their key pests come around to cause damage. The plastic covering allows light to enter, but provides a barrier to the colder temperatures. Unlike greenhouse where crops are grown in containers, crops in high tunnels are generally grown directly in the soil. High tunnels are also generally unheated, and ventilation is achieved manually or mechanically through the use of side curtains.

Location of the High Tunnel

When planning to put up a high tunnel, it is important to orient the structure so that air will move in a perpendicular manner through the house. This will help crosswinds to cool the structure when the side curtains are lowered. Good air ventilation is key to reducing the temperature and providing a passive cooling mechanism for the structure. Avoid locating the structure near shady areas or trees that will prevent adequate light from entering. However, it is also important to note that windbreaks are important because excessive winds can damage these structures. Select an area with good soil drainage or add drainage mechanisms to help move water away from the structure. 

Construction

High tunnel kits can be purchased for you to build yourself, or there are also companies that will build these structures for you. It is up to you to decide what situation would be best for you. You can find lots of information online if you choose to build your own. Even small, homemade versions will do the job and can provide the same growing conditions as larger versions.

Photo by NRCS

Covering

High tunnels are covered with 6-mil greenhouse-grade polyethylene, either in one or two layers. This plastic will need to be replaced around every four to five years due to cracking and weathering. While one layer will allow for more light transmission, two-layered plastic coverings can be inflated using a blower and can help insulate and provide a buffer for wind.

Temperature

Photo by Chris Mullins, VSU

Growing in protected structures requires more management than typical outdoor production. One of the biggest management concerns is controlling the temperature. When growing in a greenhouse, you can use heaters and vents. High tunnel controls are manual; therefore, they require more management. The intensity of the sun greatly determines the temperature inside the tunnel, and you are concerned with both cold and hot temperatures. Each plant has a range of optimum temperatures. Appropriate temperatures can affect plant yield, growth, nutrient/water uptake, pollination, and fruit formation. Just like cold temperatures, hot temperatures can also be detrimental to plants, so you must have a way to ventilate and allow for air movement with these structures.

End walls that open up can help with air transmission and also can provide a large enough opening for equipment to enter, such as small tractors and other implements. The most common method for controlling temps in high tunnels is through the lowering of the side curtains. Shade cloth can also be used.

An issue for high tunnel structures in the winter can be collapse from heavy snowfalls. Snow will need to be removed to prevent the heavy weight from bending the metal poles.

Irrigation

Irrigation systems are a must since the structure will be covered. Often, drip irrigation is the method used, because it is easy to install and manage. It also puts the water right at the roots. Drip systems also allow an easy way to fertilize through fertigation. Sometimes overhead irrigation may be used, depending on the crop. Rainwater catchment systems can be used as a way to collect water runoff from the roof to be used to water the crops inside.

Soil Solarization

Soil solarization is an option to help sterilize the soil and kill nematodes and soil pathogens that might be present. The soil is irrigated and polyethylene sheeting is placed over the soil. The structure is closed to allow heat in the soil to build up, ideally reaching above 110°F for two to four weeks.

Crops for High Tunnels

Photo by NRCS

Tomatoes are a very common crop grown in high tunnels. Tomatoes are fairly easy to grow, have a strong market, and perform well when grown in high tunnels. Cool season crops such as leafy greens also perform well. The use of additional row covers can help provide additional protection for these crops into the cooler winter months. Other successful crops include squash, cucumbers, cut flowers, ginger or turmeric, and berries such as raspberries and blackberries.

Pest Control

Generally, there are less pest pressures in high tunnels compared to outdoor growing. Pests that appear are typically those associated with greenhouses, such as whiteflies or aphids. Using Integrated Pest Management is important in a covered structure. Scout for insects, know their lifecycles, and determine what control methods are best suited for controlling the pest while causing the least disruptions to the environment. Biological controls such as the use of predatory insects find greater success in high tunnels, since the beneficial insects are contained.

Cost

High tunnel materials generally cost an average of $4-$6 per square foot. Construction will add an additional #2-$3 per square foot.

The NRCS (Natural Resources Conservation Service) High Tunnel Program is a cost share option for producers to put up a high tunnel on their farm. Some criteria for participation in the program include crop records from previous years. The crop must be grown in the natural soil profile, and site selection must be on sites that have adequate sunlight, a level grade or slope not exceeding five percent. The site should be sheltered from the wind, and avoid placing the structure in the 25-year floodplain in possible.

The high tunnel structure must be planned, designed, and constructed from a new manufactured kit, and must be six feet in height at the peak. For more information about cost share options, the program, and how to apply, contact your local NRCS office.

Additional Resources: 

For more information on growing under cover, visit the resources section on https://sites.google.com/vt.edu/smallscalevegprodweb/resources

References:

-        Chris Mullins, Virginia State University

-        https://extension.psu.edu/extending-the-garden-season-with-high-tunnels

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Importance of Cover Crops

 

Cover Crops are an important part of any healthy cropping system. What is a cover crop? A cover crop is a crop that is grown to maintain and improve soil fertility, water quality, as well as to help manage pests and diseases. Cover crops are often planted after a crop grown for harvest has been harvested, with the intention of improving soil tilth, reducing soil erosion, recycling nutrients such as nitrogen, and bringing other benefits to the farm.

Using cover crops as part of your regular crop rotation plan can increase the yield of the following cash crop.  One of the most advocated uses of cover crops is for erosion control during the winter, after the cash crop has been removed.

The type of cover crop you select is dependent upon several factors, including how you will seed it, the weather conditions, and how you will kill the crop.

Types of Cover Crops:

Legumes

Legumes are plants in the pea family. Legume cover crops are those can “fix” nitrogen, meaning that they reduce the need for nitrogen fertilizer by using root nodules to naturally fix nitrogen into a form that is usable by the plant. They can also increase the organic matter in the soil. Legumes should be planted early enough to allow for adequate growth before the first killing frost, roughly six weeks.

Non-legumes

Non-legumes include cereals (rye, wheat, oats, triticale), forage grasses (annual ryegrass), and broadleaf species (buckwheat, brassicas). These are best for scavenging nutrients, erosion control, weed control, and adding organic matter from residue. Non-legumes are best in a field that has excess nutrients, particularly nitrogen. They can scavenge 150 pounds of nitrogen per acre.

In organic farming, cover crops are critical way in which nutrients are added to the soil. In addition to adding nutrients, they provide organic matter which Is a more long-term goal when considering soil health. Cover crop may be left as a mulch or incorporated. If cover crop is incorporated into the soil before planting the main crop, it is called a green manure.

With some crops like pumpkins, a cover crop is killed and the pumpkins are planted into the residue, which is used as a way to conserve water, control weeds, and can even keep the pumpkins cleaner by reducing splashing of dirt and mud.

Pumpkins being planted into a killed oat cover crop.

Consult Virginia Cooperative Extension for more information on selecting appropriate cover crops for your farming operation. No matter which cover crop you decide to utilize, you should devote as much attention to them as you do your cash crops to prevent failure and problems throughout your cropping system.

Sources:

https://www.sare.org/Learning-Center/Topic-Rooms/Cover-Crops

http://www.tolweb.org/notes/?note_id=3920

https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1043183.pdf

COVID-19 and Fall Agritourism Operations

Fall is normally an exciting time filled with pumpkin festivals, pick-your-own pumpkin patches, apple picking, corn mazes, Halloween events, and more. As we are all aware, COVID-19 has drastically changed the way we do things. Many large events like fairs and festivals were canceled. If you operate a small agritourism operation, you may be wondering how to keep your operation running during this unprecedented time.  

Many families are looking for outdoor events and activities to entertain themselves and get out of the house. A day spent at a smaller agritourism operation this fall might be just what these families are looking for. As the farm owner, it is up to you to determine if your operation can continue safely while following state guidelines and keeping patrons safe. The following are some suggestions and resources on COVID-19 prevention best practices that you can use to reduce risk and ensure your fall agritourism activities can proceed.

Staying Up-to-Date on State Guidelines

In Virginia, we are currently in Phase III of the Virginia COVID-19 guidelines. These guidelines can be found at  https://www.governor.virginia.gov/media/governorvirginiagov/governor-of-virginia/pdf/Forward-Virginia-Phase-Three-Guidelines---8-21-2020.pdf. These guidelines contain physical distancing best practices, enhanced cleaning and disinfecting best practices, and more, for different types of business operations. Your agritourism operation might fit into different categories, so carefully read and follow the guidelines that best suit the activities in your operation.

Communication of Operation Practices

While it is imperative that you develop COVID-19 guidelines for your operation, they must be clearly and effectively communicated to your customers if risk is going to be reduced. Before customers arrive on the farm you should share the steps you will take to protect their health. The use of websites, social media, newspaper ads, tv or radio ads, and signage are all effective ways you can share your policies with the public.

Request that customers not come to the farm if they are displaying any symptoms of COVID-19 or other contagious illnesses. Ask customers showing symptoms to leave. Communicate verbally and by signage that customers should wear a face covering that covers their nose and mouth.

Reducing Congregating

One of the best things you can do to reduce risk of spreading COVID-19 is to establish policies and practices that maintain appropriate distance between persons not living in the same household. Families can be kept together, but you should provide clear signage and communication of how to best distance people away from one another. Be clear when folks arrive that families must keep a minimum of six feet from other families. In areas like pumpkin patches, this should be easy to do, but you might need to reduce the allowed occupancy in the patch at one time (depending on the size) to have enough room for folks to spread out. Design a flow plan for customers to enter and exit the venue. Additional practices might include separating tables or benches, marking places to stand in line, or reducing crowding around entrance areas, checkout lines, or areas around bathroom facilities. Consider if you should cancel or restrict certain parts of your operation or event that might make social distancing difficult (concerts, picnicking, etc.). Can you offer appointments or scheduling for families in order to better manage the number of people on your operation at a time and allow for sanitation between groups (hay rides or corn mazes for example)? Should you restrict access to certain parts of the farm?

Sanitation Stations

Promote frequent and thorough hand washing. Provide customers a place to wash hands with soap and water, if possible. Portable handwashing stations can either be purchased or made with minimal costs (see DIY Handwashing Station link below). If soap and running water are not available, provide hand sanitizers. Proper hand washing signage should be posted at wash stations, and other resources are available online or by contacting Virginia Cooperative Extension.

Signage

Signs should be posted at the entrance to your operation that clearly detail your COVID-19 procedures and management plan. Statements should be posted that detail social distancing requirements, sanitation requirements, screening procedures, flow plans, location of sanitation stations, and other applicable information.

The website https://www.virginia.gov/coronavirus/ has information about the Phase Three guidelines, as well as printable posters on requiring face coverings.

The website https://iowavalleyrcd.org/markets/covid19fmsigns/ contains lots of great colorful and downloadable posters that can be used on agritourism operations, social media, as well as at farmers markets or fruit/vegetable stands.

Customer Flow

Depending on what type of operation you have, it might be helpful to develop a flow plan. This is where you design a foot-traffic pattern for walking the field or other space in your venue to help distance people away from each other.

Employee Training

Employees should be screened and monitored just as visitors are. They also must be trained on your personal and farm safety protocols put in place to minimize risks of COVID-19 transmission. Document the training, including when it took place and what employees were trained on. Have employees sign verifying completion of the training. Instruct employees that are not to work if they are sick with COVID-19 or displaying symptoms. Employees should wear face coverings, and are required to wear them if they are working in dining services.

Recordkeeping

Just as with food safety, it is always a good idea to document your procedures being taken to minimize risks. Document training and cleaning and sanitation practices. Keeping adequate records will help ensure others that you are adequately doing your part to reduce risks to all those involved in your operation.  

For assistance designing your COVID-19 management plan for your agritourism operation, contact Virginia Cooperative Extension or view any of the resources below.

Additional Resources and References:

•          Best Management Practices for U-Pick Farms During the COVID-19 Pandemic
• https://smallfarms.cornell.edu/resources/farm-resilience/best-management-practices-for-u-pick-farms-during-the-covid-19-pandemic/

•           Coronavirus (COVID-19) in Virginia
• https://www.virginia.gov/coronavirus/

•      COVID-19 Response Plan Template for Fruit and Vegetable Farms
• https://docs.google.com/document/d/12sLifH-6Dm48lm_s2OIM3rIrN54Fv__z_i52Mvy5yGA/edit

•           DIY Handwashing Station
• https://extension.umn.edu/growing-safe-food/handwashing-station

•           VDACS COVID-19 Emergency Information Center
• https://www.vdacs.virginia.gov/about-emergency-information.shtml

•           Virginia Agritourism Phase III Updates (Recording)
• https://www.facebook.com/355846805259801/videos/638010510457935

 

 

 

The Importance of Soil Testing

Don’t guess, soil test!

Soil testing is a critical part of producing a successful crop, whether that be fruits, vegetables, forages, turf, or ornamentals. A soil test informs us of the fertility of our soil by telling us the levels of several essential nutrients present, as well as the relative acidity or pH. These results aid us in selecting plants, preparing our soil, selecting and applying the correct fertilizers, and identifying problems. Overfertilization can cause excessive plant growth, increase diseases, lead to increased pollution, as well as just being costly. Soil testing gives you precise measurements, leading to better decision making and ultimately more productive plants.

When you are considering growing a crop, the first thing you should do is conduct a soil test. This can help you make appropriate decisions and prepare your land accordingly.

Soil testing is the only reliable way to test soil pH. Soil pH affects nutrient availability to the plant. Most nutrients are at their optimal availability to plants between a soil pH of 6 and 7. However, some plants such as blueberries require more acidic soils. A soil test will tell you the pH, as well as provide you with recommendations to modify the pH for your selected crop. Substances such as sulfur can lower soil pH, while substances such as lime will raise soil pH.

Soil testing can be done at any time, however, you will want to give yourself time to allow for adjusting pH before planting if that is necessary. Depending on the substance used, It can take 6 months or more for added lime to begin providing benefits. 

So you know why to test your soil, but how do you do it? Soil testing is a service provided by Virginia Tech. You want to sample your soil when it is not too wet. Sampling in the fall is usually best for farmers to allow for adjusting pH. You want to divide the area into units if the area or field is not uniform, or if different areas are unique (garden, lawn, flower bed, crop field, etc.) You want to obtain a good, representative sample of soil. Sample in a zig-zag pattern across the area. Samples should contain at least 5 subsamples from the area mixed together, with each subsample taken at a depth of around 6 inches for plowed land, or 4 inches for pasture or lawns. You may sample with tools such as a soil probe or spade.

Soil probe with a soil core sample

The soil information sheet must accompany any sample sent to the Soil Testing Lab. This sheet can be found online or at your local VCE office. Take time to fill in the blanks to the best of your knowledge. If you need assistance your Extension agent can help you. Make sure the sample identifier on the sheet matches that of the sample box, and that you fill out the correct plant code for the sample you submit.

Soil tests at Virginia Tech are $10.00 per sample for a routine package. Routine tests make recommendations for the following: P (phosphorus); K (potassium); Ca (Calcium); Mg (Magnesium) and five micronutrients, as well as pH. Commercial farmer samples are free of charge. Results are typically received within a week, unless there is a delay due to a large number of samples being sent in.

How Does My Farm Become USDA Certified Organic?

Organic production has been growing in popularity for many years. The actual term “organic” is a labeling term used to identify agricultural products that have been grown and processed according to certain standards. These standards incorporate cultural, biological, and mechanical processes that foster cycling of resources, promoting ecological balance, and diversity (National Organic Program). While you often hear of many farmers who choose to follow the practices of organic growing, there are actually regulations which determine whether or not you are allowed to label your product as “organic.”

According to the National Organic Program, all products that are sold, labeled, or represented as organic must meet all requirements in the USDA organic regulations. This program, the USDA National Organic Program, is in place to ensure that there are consistent standards nationally. Certified organic products must become certified by a USDA-accredited certifying agent, or third-party certifier.

For small operations, there is an exemption. Operations whose gross agricultural income from organic sales is less than $5,000 do not have to be certified in order to sell, label, or represent their products as organic. They must follow organic practices, and may use the word “organic,” but are not allowed to use the USDA organic seal.

What about the rest of us?  The certification process as a whole can take on average from 3 to 6 months, and the cost can range from $1,000 to $5,000, depending on your certifier and size of farm. The first step is to find an organic certifier. There are many, and a database can be found at https://www.ams.usda.gov/. Your certifier will help you get started and will be able to answer questions. In order for your land to become certified organic, farm land must have not had any prohibited materials applied to it for three years before becoming certified. Land that has had no prohibited materials applied may become certified immediately.

You will need to develop what is known as an organic systems plan. This plan is a detailed outline that explains how you intend to operate your farm or ranch to satisfy the requirements of the regulations (ams.usda.gov). An important part of this plan is the materials list, where you list out all of the chemical and other inputs that might be used. If you needed to adjust or add to this list, you would need to contact your certifier to make sure the input is approved and not a prohibited substance.  

As far as the types of practices you will need to put into place, organic crop production puts emphasis on land having no prohibited substances added. Soil fertility and crop nutrients are managed through tillage, crop rotations, and cover crops. Supplemental nutrients may be added with animal and crop waste as well as allowed synthetic materials. Crop pests including insects, weeds, and diseases must be controlled using physical, mechanical, and biological controls. If additional tactics are needed, only those that are approved may be used. Many products approved for organic production may have an OMRI label (Organic Materials Review Institute), meaning the product has been reviewed to determine if it is allowed. Pesticides derived from natural materials or living organisms are allowed as long as they do not contain synthetic additives or are not prohibited on the National List (ams.usda.gov). You must only use organic seed or plant stock when available, and the use of any genetically engineered material is prohibited.

While the certification process may seem daunting, Virginia Cooperative Extension is available to help you and provide resources as you work toward your certification.