5 Key Pieces of Advice for Growers Preparing for the Transplanting Rush
PLEASE NOTE: SINCE THE ORIGINAL PUBLICATION DATE OF THIS BLOG POST THERE HAS BEEN A MATERIALS UPDATE ON THE NATIONAL ORGANIC PROGRAM (NOP) STANDARDS. There was some concern that because paper chain transplanting pots contain a synthetic substance they should not be approved for use in organic production. As of January 2019, the NOP has reversed their decision to put paper pots on the prohibited substances list and are allowing certifiers to approve the use of paper pots on certified organic farms until further notice.
Between now and the end of June, the largest amount of planting work will take place for growers in the northeast. The summer solstice generally marks the turning of the tide: it is when we shift from large plantings to large harvests. In preparation for this, the busiest planting time of the season, we’ve put together a few pieces of advice on how to help your transplants along with their transition.
Practice your ABC’s (Always Be Checking). When your transplants are ready to go, there’s no time for hesitation. Keeping plants in their starting trays once they’ve outgrown that space can lead to unnecessary stress and stunted growth. That’s why it’s wise to “always be checking” your transplants – daily – to make sure they are healthy and happy right up until the time they should be moved out of their trays. By checking their status every day, you’ll get a keen sense of when the plants will be ready to go out into the field and can plan ahead with regards to labor, infrastructure, and weather. Transplanting is a stressful activity for a plant; remember that in the natural world, plants are not dug up and replanted or moved around – they are stationary, always seeking to build a stronger root structure and adapt to their surroundings. To minimize the negative impacts of this unnatural transition and maximize the chance of success, growers should make sure their transplants are as robust as they can be when it’s time to transplant – not overly mature or too immature, but wholly ready for their transition.
Water, water and more water. It can’t hurt to say it repeatedly: you must, must, must water your transplants sufficiently right before you transplant them. Soak them. No, really, soak them. And then soak them again. Especially if it’s a dry day, but even if it’s a rainy day, water them. Even if you use a water wheel transplanter that puts water right in the planting dibble when they go into the ground, water them. Even if you think you’ve watered them enough, water them again. Did we mention that you should water your transplants before planting?
Ok, but on a serious note: the only drawback to saturating your transplants right before planting can be if you use soil blocks instead of cell trays. Many growers prefer soil blocks for the benefits they provide (better air circulation, fewer root-bound transplants, less use of plastic trays and pots, quicker transplanting in the field), but if you over-water them the blocks can lose their form and disintegrate in your hand when you try to grab them for transplanting. If soil blocking is your preferred method of propagation, you should still water your transplants well before they go into the ground, and be sure to get a drip line or overhead irrigation system set up for them soon after they are planted into the field or garden, or even during transplanting. It’s also a good idea to mix some fish emulsion fertilizer into the water you use for transplants before they go into the ground; this will give them an extra boost of nutrients for the transition, and keep them growing at a healthy rate even if the transplanting conditions aren’t ideal.
Plant with gentle efficiency. It may sound surprising, but transplanting well and quickly is one of the trickiest skills to teach new farm workers. Even though you want to move quickly if you’re working in a commercial capacity (time is money!), transplants are still tender young plants that have been babied all their lives – they usually can’t withstand rough handling, or at least they don’t like to. On the other hand, plants are surprisingly resilient, and if you’ve done the proper legwork to make sure your transplants are vigorous and healthy, you can move pretty quickly getting them into the ground without taking five minutes on every plant. The key is to be gentle, but efficient. Tamping down the soil around each plant is a classic newbie mistake – it compacts the nicely prepped and aerated soil and sheds water down and around the plant instead of slowly absorbing water at the base. Similarly, planting too deep or too shallowly can be common mistakes. With the exception of leeks and onions which can be buried up to several inches into the soil, most seedlings, if they are at the correct maturity for transplanting, should be set in the ground so the soil just covers the shoulders of the soil block or cell of the transplant. If the cells are planted too shallowly and are peeking out from the ground, they are at risk for root exposure and stem breakage; planting too deep can stunt the plant’s growth. With a pre-dibbled bed, each seedling should take just a few seconds: create a deep enough hole for the cell or soil block with one hand, and with the other hand place the transplant into the space you’ve created. Then swiftly cover the soil block or cell with the soil that was moved to create the dibble, gently filling the hole back in without excessively tamping down around the base of the plant. Or, if you're on the back of a transplanter, use one hand for the entire process.
Step up your infrastructure game. There are lots of little infrastructure improvements that can help growers on every scale with the task of transplanting, from a greenhouse hose trolley to a rolling dibbler. The most important thing is to make investments that fit with your systems. Richard Wiswall, owner and founder of Cate Farm and author of the popular Organic Farmer’s Business Handbook, cites his seedling tray greenhouse trolley as his favorite farm tool. As with most of the tools Wiswall recommends for organic farmers, the trolley is a design that helps farmers work smarter instead of harder. If you spend a good amount of time every spring walking back and forth down the rows of your propagation house, this nifty tool can help save your body and your time: it is an overhead metal rod installed in a loop between two greenhouses that creates a track upon which a shelved trolley can easily carry multiple trays of seedlings from one house to the other, or from one house to outside for hardening off or transporting to the field.
A note on paper pots. Some of you may have been made aware of the recent news that the use of paper pots (a critical tool for taking advantage of this Japanese-manufactured transplanting system) may or may not be continued to be allowed in certified organic systems in the U.S. This excerpt is from the March 2018 issue of Growing for Market magazine, in which John Hendrickson of Small Farm Works, the importer of the Japanese-manufactured paper pot chains, explained the current developments regarding the use of paper pots in certified organic farm systems: “The use of paper pots on certified organic farms in the U.S. is complex and uncertain. What has developed over time is that some certifiers have been allowing the paper pots to be used and some have not, based on differing interpretations of the National Organic Program (NOP) rule regarding the use of paper and paper products. It is my understanding that the NOP will be making an official ruling on the use of the paper pots, but that there is no timeline for that decision to be made or announced. The research and development process has begun to create a paper pot or paper pot system that could be approved more universally for organic agriculture.” As of January 2019, the NOP has reversed their decision to put paper pots on the prohibited substances list and are allowing certifiers to approve the use of paper pots on certified organic farms until further notice.