Expanding raspberry production options for acreage expansion, long-term sustainability, risk mitigation, and season extension
Funded by a Specialty Crop Block Grant (23SCBPOHI204) from USDA Agricultural Marketing Service Through Ohio Department of Agriculture
Dr. Gary Gao, Professor and Small Fruit Specialist
South Centers and Department of Extension
College of Food, Agricultural and Environmental Sciences (CFAES)
The Ohio State University
Pros and Cons of Growing Long Cane Raspberries
- Growing Long Cane Raspberry for Fruit Production in High Tunnels
- Growing Long Cane Raspberry for Fruit Production in Greenhouses
- Obtaining Long Cane Raspberry Plants
- Growing Long Cane Raspberry Bushes on Your Own Farm
- Reusing “spent” Raspberry Bushes
- Long Cane Raspberry Production Videos
- Grower Outreach and Feedback
- Useful References
- Acknowledgements
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Pros and Cons of Growing Long Cane Raspberries
More consistent production and higher yields, bigger and better tasting berries, less dependance on good soil drainage and favorable weather conditions, and season extension are some of the main benefits of long cane raspberry production. What is the long cane raspberry production? Long cane raspberry production system is a relatively new raspberry production method where raspberry bushes with long floricanes (5 feet and 10 inches) are produced in high tunnels or greenhouses, stored in coolers at 2-3 degrees below freezing in autumn and winter and then shipped to growers at their desired pullout time for planting and fruiting in spring, summer or fall.
Growers can plant these “ready-made” raspberry bushes with fruiting canes in a soilless media (Figure 2) and grow them in a protected environment like a high tunnel or a greenhouse or even under solar panels for fruit production in summer. This new and innovative system could help growers get around the problems of poor soil drainage that limit new cane growth and fluctuating spring temperatures that damage floricanes. The long cane production is extremely popular in Europe and North America including Canada, Mexico, and US.
Based on a presentation entitled “Tulameen raspberry long cane: from root to fruit” by Valérie Bernier-English, M. Sc., R&D Manager, Onésime Pouliot Farm, at the 2019 NARBA Conference, Savannah, Georgia, the breakeven point is 800 grams of fruit per cane with 6 canes per linear meter. Growers in Quebec, Canada were about to achieve an average yield of 1.2 kilograms per cane.
We evaluated this production from 2021 to 2023, and then 2024. We were able to reach a yield of 800 grams per cane in 2023. Our plants grew more and produced more fruits in 2024. However, we still need to make quite a few improvements to our production protocol to reach the yield goal of 1.2 kilograms per cane in a six-cane-per-linear meter spacing.
Growers who are looking into long cane production in Ohio still need to weigh the pros and cons of this system. Even though growers can potentially produce 22,000-25,000 lbs of high-quality raspberries with this system, many challenges, such as a sharp learning curve, high upfront and ongoing costs, severe labor shortage, hyperinflation, diseases, mites, hot temperatures, excessive sunlight can turn a profitable business into a money losing one.
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Growing Long Cane Raspberry for Fruit Production in High Tunnels
High Tunnels: Various high tunnels can be constructed and used for long cane raspberry production. It is beyond the scope of this publication to discuss construction of high tunnels. The height of the high tunnels needs to be at least 12 feet tall to accommodate the heights of the raspberry plants. We copied the design of the raspberry umbrellas used at Onésime Pouliot in Quebec, Canandasince these umbrellas are less expensive than typical high tunnels. The owner at Onésime Pouliot in Quebec, Cananda mentioned that they anticipate a twenty-year lifespan of these structures. Plastic field may be replaced every a few years depending on the quality, care, and weather conditions in your area. Protect structures like high tunnels and umbrellas are absolutely essential for ensuring excellent plant growth, high yields, and fruit quality.
Long Cane Raspberry Plants: Long cane raspberry bushes with canes that are about 5’10” long can be purchased from a number of nurseries in US and Canada. However, the numbers of vendors and selections of varieties is still limited. Since these long cane plants need to be kept 2-3 degrees below freezing in a refrigerated truck, the shipping costs can be extremely high! In addition, some vendors need an order to be placed a year ahead due to limited production and capacity. Some varieties also carry a royalty fee on top of the plant costs. About 240 to 280 canes can be packed in a wooden crate, which carries a charge of about $120 per crate.
Containers or Pots:
Seven-liter square pots seem to the ideal size for growing long cane raspberry plants for fruit production. The pots used are specialized ones with legs on the bottom for better water drainage. These pots can be purchased from various sources. One source is Hortamericas.com Here is a link to the 7-liter pots: https://hortamericas.com/catalog/growing-supplies/containers/beekenkamp-7-liter-square-pot/?srsltid=AfmBOopli1AJ2NdzVfGjtTWtwOY9_Uj2uHud_04aPzBZdg94HhJ0GBCr
We are not necessarily endorsing this company. Growers are encouraged to do their homework for the best source for them. Ten-liter pots can also be used. However, they are more expensive. We have used both sizes and found them to be similar in performance. The added costs of the 10-liter pots do not necessarily translate into significantly higher yields.
Growing Substrate or Media:
The media used in our study was Cyco Coco pear, which coco coir with perlite. It was washed coco coir with 30% perlite. It was pre-buffered, and pH stabilized. The plants grew quite well. We did not notice obvious nutrient deficiencies. The media have good drainage. We did not notice any root rot issues. It is hard to know if this was the perfect media since we did not compare different substrates. It is possible for growers to mix, wash, and buffer their mixes. We were not knowledgeable enough to make it happen. A group of researchers at North Carolina has also been testing pine bark as an alternative substrate since it is a byproduct of the paper industry. It will be interesting to see if their mixes will be able replace coco coir.
Since coco coir with perlite can be quite hydrophobic, it is critical to pre-moisten the media in a large tub with water and then mix them well before putting them in the 7-liter pots.
Potting Up the Long Cane Raspberry Plants:
The long cane raspberry plants come in 2-liter pots and the roots were frozen when they came out of the delivery truck. After they were thawed a little, the two-litter nursery pots were cut off with a knife. Three to four vertical slits were made on the root balls to help the roots grow out and prevent them from growing in circles. The plants are then transplanted to 7-liter pots. It is important to make sure that root balls and canes are placed in pot as centered as possible.
Setting out the Potted Plants:
The ideal time to pull out and pot up the plants varies quite bit. We potted up our plants in May since we do not have a cooler that can keep the temperatures 2-3 degrees below freezing. We transplanted our raspberry bishes as soon as they were deilviered in May. In theory, plants can be delivered and potted up at different times to extend fruit harvest season. However, the shipping costs are too high for us. We could only afford one delivery time per year. Since raspberry plants grower better during the cooler time of the season like spring. We may experiment with an earlier plant delivery to take advantage of the cooler temperatures in spring.
The pots were placed about 1.1 foot apart so that three plots can fit in about one meter width. Horizontal wires were run from one of the row to the other. Canes were then clipped to the wires.
Fertigation
Both fertilizer and water are delivered through two injectors. Thirty two gallon garbage canes were used as tanks for stock solutions. First injector and garbage can are for a complete fertilizer, which is Peter’s 5-11-26 in our trial. Second injector and garbage can are used for calcium nitrate. Both fertizers are greenhouse grade and easily souble. The third injector was designed for acid injection. Our water does have high alkalanity. Since the water pH was in the right range, we did not inject acid in 2024. We will add a third garbage can for sulfuric acid stock solution in 2025.
Fertilizer Management
Fertilizer management is very important when it comes to long cane raspberry production. All nutrients are provided in the irrigation solution. OSU South Center utilizes a two stage fertilizer injection system. This consists of Tank A containing calcium nitrate (15.5-0-0) and Tank B consisting of a complete fertilizer (5-11-26). Fertilizers are weighed out and mixed into a solution in five gallon buckets prior to putting in the large stock tank for irrigation. Air stone were added to each of the stock tank to keep fertilizer solutions remaining in a thoroughly mixed solution. During each irrigation cycle fertilizer injectors pull solution out of each tank and mix together as it is fed through the irrigation lines. We typically irriagte 12-15 times daily for about 3-5 minutes each time.
Nutrient management is very important in the production system. One way to monitor the system is to check the EC (electroconductivity ) of the water. This is an reflection of the salts in the water which can build up in the pots and cause damage to the raspberry plants. The EC can be tested by collecting water from the system then tested using an EC meter. Irrigation water will need to be collected in several locations so that one can get a complete picture of what is going on in the potted berries. First you will want to collect irrigation water straight from the emitter drip lines, this way the EC of the fertilizer water can be tested before it makes its way through the coconut coir mix. The drain water will need to be collected from the pots and EC tested as well. At the OSU South Centers we did this by placing 3 emitter sticks directly into a black bucket to collect the irrigation water at each cycle. Three Potted plants were also set up using a collection system which drained into a black bucket to collect any drain that flowed out the bottom of the pots and each cycle. Water sample were then collected at the start of each day before the first irrigation. This allows to test our water in both locations for the EC of the water. We could then add the drain EC and the drip EC together to decide how the fertilizer needed to be adjusted to reach the target EC of 3.5 during the vegetative growth stage and 3 during fruiting stage. This can be adjusted by changing the injection ratio or by changing the irrigation run time and frequency so the target can be achieved.
Pollination
Effective pollination is absoutely essential for fruit set, fruit size and ultimately great yields. We used both bumblebees and honeybees for pollination. In a high tunnel, both bumblebees and honeybees are able to get in without any problems. However, bumblebees may be easier to handle than honeybees.
Figure 16. Honeybee hives at the OSU South Centers. Photo by Gary Gao.
Figure 16. Bumblebees (Natupol Excel) by Koppert. Photo by Gary Gao.
Insects and Mites
One of the main challenges with raspberry prodction in high tunnels is two spitted spider mite (TSSM) damage due to high and dry condictions without rains washing the mites avway. A typical symptom of TSSM date is what is called a ‘Mite burn.’ Leave turn a golden to brown. The damage can be severe and cause a severe yield loss. Damages are typically observed first on the lower leaves and progress upward.
Shade cloth and mist can be used to lower temperatures and increase humidity in high tunnels. Application of labelled miticides can also help too. Since raspberry plants can be pulled out at different times of the year, pulling the plants out at cooler parts of the season can be an effective way to aviod the hot and dry weather conditions in a high tunnel.
Raspberry leave showing yellow and brownzing discoloration. Photo by Dr. Gary Gao, The Ohio State University.
Growers can refer to the Midwest Fruit Pest Management guide online at https://ag.purdue.edu/department/hla/extension/_docs/id-465.pdf This guide is upated everyone other year. Please check back for the current recommendations. Groweres need to keep in mind that high tunnels are treated like greenhosues in some states, but not others. They need to check with their state Extension professionals for recommendations. In Ohio, high tunnels fall under greenhosues.
Disases
Botrytis fruit rot (Gray mold) and late leaf rust are two fungal diseases that were found in our trial. Quite a few opne flowers aborted befiore they develped fruits. Botrytis spores were found on those aborted flowers. However, high tempertures and low humudity may have been the primary cuases of flower abortion. Botrytis fruit rot may have player a less prominent role than the other two environmental factors. Raspberry late leaf rust appears later in the season and may not be a yield-limiting disease.
Growers are encouraged to conduct their cost and benefit analysis of a disease management program. Effective disaease management is definitely needed for good yield and quality. However, the profitability needs to be main drivng froce for a commercial operation.
Summary
Long cane rapsberry production can be a profitable venture for growers. There are quite a few successful examples in Canada and US, as well as few countries in Europe. We believe that this system has a lot of great potential in Ohio. However, there are quite a kinks that need to be worked before we can recommen this system for wide adotpion in Ohio.
Helpful links:
Lisa Rayburn, NCSU; Josh Mays, TriEst Ag Group, Inc.; James Hewitt, Lewis Nursery and Farms; and Gina Fernandez, NCSU. “Growing Long-cane Raspberries in the Southeast.” The article can be retrieved online at https://smallfruits.org/2022/07/growing-long-cane-raspberries-in-the-sou...
Perennial. “Long Cane Production Guide.” Follow this link for a PDF online at https://www.perennia.ca/longcaneraspberryguide/ Growers have to register with Perennia to get this guide.
Acknoledgements
I would like to thank Thom Harker, research associate; Wanye Lewis, farm manager, and Dane Peck, research asistant; and Dr. Logan Minter, Field Speciaist, OSU South Centers, CFAES, The Ohio State University for their technical assistance with this project. My sincere appreciation also goes to Dr. Pengfei Wen, professor and associate dean, Horticulture College, Shanxi Agricultural Unviersity, China for his valuable suggestions and technical help. I thank Ms. Lane Song, associate professor, Shanxi Agricultural University, China for helping with plot maintenace.
“Funding for Project and Publication was made possible by the U.S. Department of Agriculture’s (USDA) Agricultural Marketing Service through Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the USDA.”
This publication was financed in part or totally through a grant from the Ohio Department of Agriculture, the State of Ohio, and the United States Department of Agriculture under the provisions of the Specialty Crop Block Grant. This [publication or project] was supported by the U.S. Department of Agriculture’s (USDA) Agricultural Marketing Service through grant 23SCBPOHI204. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the USDA.