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  • Seed Trays
  • The History of The Air Prune Tray

    August 11, 2023 3 min read 0 Comments

    air prune

    Whether you are a hobby farmer or are growing flowers as a business, you have probably heard of the many benefits of air pruning. You may even own trays, containers, or fabric bags with air pruning capabilities.

    What is Air Pruning?

    Air pruning is a term used in agriculture that refers to the action of the feeder roots reaching the air and drying out as a form of pruning. This action stimulates root branching to form, creating a more fibrous and productive root system.

    This process is advantageous for a new seedling because the increased root system surface enables the young seedling to uptake more water and nutrients, causing the plant to grow stronger and healthier. Air pruning also helps to prevent root circling and transplant shock. 

    The Dutch used a technique referred to as perspotten or soil blocking over 100 years ago to achieve this air prune environment for their new seedlings.

    What is Soil Blocking?

    Soil blocking uses a compressed square of soil blocks, aka press pots - formed with a specific hand tool or a line press in commercial applications and are held together and assembled with growing media and moisture. Blocks allow the top and side air pruning to occur. The Dutch developed modern type soil blocking, but the practice has been around for thousands of years in Central America. 

    soil blocking

    Air Prune Tray History

    This practice in a commercial setting is tedious, so growers often use plug trays instead of creating the blocks. This was until Dutch immigrant Aart Van Wingerden developed the air prune tray design in Mills River, NC, in 1996.

    When emigrating from Holland, Aart Van Wingerden brought a lot of advanced Dutch agriculture technology with him. Aart sought to recreate the benefits he had seen from soil blocking, a practice that he had learned as a child growing vegetables with his father in their small village.

    He invented a style of air pruning tray to avoid typical root-curling issues he had noticed with the use of a standard plug tray. In solving the problem of root-bound seedlings, he created a lasting legacy in seed propagation tools. Van Wingerden is also credited with many advancements in greenhouse technologies. Check out his impressive roster of patents here

    Aart and Cornelia Van Wingerden emigrated from Ridderkerk, Netherlands to the United States. He found a sponsor, packed his few belongings, and sailed for America. He arrived May 10, 1948, in the harbor of New York City with his wife, three boys, six dollars, and a belief that he would find better opportunities in America.

    Over the next 70 years, the Van Wingerden family fanned out establishing successful greenhouse nurseries in six states as well as back in Holland. They also run a very successful nonprofit organization that focuses on agricultural projects in developing countries. Many of his 16 kids and 112 grandchildren operate nearly 20 horticultural and farming businesses from Connecticut to Colorado. Aart Van Wingerden’s advancements have made life easier for growers like us today.  

    Picture Credit:  Greenhouse Grower Magazine. April 1995.

    Bootstrap Farmer’s Air Prune Tray

    With input from Bootstrap Farmer’s product testers and clients, we have created our version of the iconic Van Wingerden design patented 26 years ago, which expired in 2016. As long time admirers of this design, we got right to work on drafting drawings for the design in 2016. 

    Once the drawings were complete we realized how complex of a mold it would be to produce. Wanting to get it right, we decided to hold off on its production as we were not confident with our overseas manufacturer's ability to build something this intricate. Additionally we had dreams of moving production to the USA. We started accomplishing this goal in 2020 and have found partners in manufacturing that we truly believe in. Enough so, that we put our take on the air prune tray into their hands.

    In addition to the 72 cell air prune tray, we also offer a 6 cell plug tray insert and various-sized grow bags that feature this air prune technology.


    Works Cited

    Van Wingerden, Aart. “Philosophy – Van Wingerden International.” Van Wingerden Internationalhttps://www.vanwingerden-intl.com/philosophy/. Accessed March 14, 2022.

    “History – Van Wingerden International.” Van Wingerden Internationalhttps://www.vanwingerden-intl.com/history/. Accessed March 14, 2022.

    Henderson, Nancy. South Central Growers Provides Marvelous Mums. Farm Flavor Media/Journal Communications Inc., 2021. Tennessee Home and Farmhttps://tnhomeandfarm.com/agriculture/south-central-growers-provides-marvelous-mums/.

    “Van Wingerden Family History – Grower Direct Farms.” Grower Direct Farmshttps://growerdirectfarms.com/our-history/  Accessed July 11, 2023.

    Page, Petra. “Soil Blocking in Five Easy Steps - Cornell Small Farms.” Cornell Small Farms, April 5, 2021. https://smallfarms.cornell.edu/2021/04/soil-blocking-in-five-easy-steps/. Accessed March 15, 2022.