Tree Diapers: What Are They and How Have They Helped the Arboretum?

We all need a lit­tle help from time to time. When it comes to keep­ing a trans­plant­ed tree prop­er­ly hydrat­ed, this is cer­tain­ly the case. A prod­uct called a tree dia­per has great­ly improved the way we make sure new­ly trans­plant­ed trees get the hydra­tion and pro­tec­tion they need. The name might sound fun­ny, but you’ll soon real­ize how invalu­able the tree dia­pers are. Let’s learn a lit­tle more about what a tree dia­per is and how it fac­tors into oper­a­tions at Shel­by Avenue Arbore­tum.

The Ins and Outs of Trans­plant­i­ng Trees

There are a vari­ety of com­pli­ca­tions that can arise when trans­plant­i­ng a tree, just like how organ trans­plants in humans call for a seri­ous amount of cau­tion and care. No mat­ter how you look at it, mov­ing a tree is in some way trau­mat­ic to the tree. The goal of arborists when trans­plant­i­ng trees is to make sure that trau­ma is min­i­mal and that poten­tial long-term dam­age is avoided. 

We don’t say trau­ma in order to dra­ma­tize how a tree feels. Trees don’t feel in the tra­di­tion­al sense, but as liv­ing things, they can only take so much at once before their sys­tems are irrepara­bly dam­aged. Slop­pi­ly mov­ing a tree from one loca­tion to anoth­er with­out con­sid­er­ing the depth of your dig, soil com­po­si­tion at the old and new sites, and a myr­i­ad of oth­er health fac­tors will kill a tree. 

Trau­ma, or trans­plant shock as many arborists call it, is a real prob­lem when mov­ing trees, even if their cur­rent loca­tion is not ide­al. Trees are not nat­u­ral­ly inclined to move. When they put down roots, that’s meant to be it. They make do with what they have, and they either suc­ceed to grow ful­ly or they die out. With human inter­ven­tion, trees can be moved with a very high rate of suc­cess. How­ev­er, there are many things that an untrained indi­vid­ual can do wrong between uproot­ing and replant­i­ng a tree. 

Explain­ing the Tree Diaper

One of the pri­ma­ry sources of trans­plant shock in trees is inad­e­quate water. New­ly moved trees require a lot more water than a tree that wasn’t moved. Water helps a tree in many ways. Most of us know that water is crit­i­cal for hydra­tion and car­ry­ing nutri­ents through­out the tree. What you may not know about trans­plant­ed trees is that water also helps a tree estab­lish itself. Hydrat­ed soil is more mal­leable and adapt­able, mak­ing it eas­i­er for a tree to set­tle into its new place rather than stick out like it doesn’t belong. On the oth­er hand, too much water in a trans­plant can cause the oppo­site effect, mak­ing the tree unsta­ble and over-hydrat­ed. The tree can get too much water, and the water can also attract mold and fun­gi that can harm these weak­ened trees. 

This is where the tree dia­per comes in handy. A tree dia­per is a ring-shaped device that goes around the trunk of a tree or shrub. These are typ­i­cal­ly used when trans­plant­i­ng trees, but tree dia­pers have their uses in any set­ting, even for gar­den­ing and plants that are much small­er. They are a prod­uct designed by a com­pa­ny called Zyn­no­va­tion based out of Ash­land, Vir­ginia. This prod­uct works excep­tion­al­ly well in a num­ber of use cas­es, which is why it’s used by arborists all around the world. 

How Does a Tree Dia­per Work?

Here’s exact­ly how the tree dia­per works and some of the sce­nar­ios it can help in besides trans­plant­i­ng. A tree dia­per is a donut-shaped ring of plas­tic fab­ric with super-absorbent poly­mer pel­lets con­tained with­in. When dry, they are light and easy to store. When you first get a tree dia­per, you ​“charge” it by immers­ing it in water for sev­er­al hours. Because the device is designed to release water slow­ly, it also absorbs water quite slow­ly. This is inten­tion­al to pre­vent over­wa­ter­ing. In places where total drought isn’t a year­ly con­cern like Nashville, the tree dia­per can usu­al­ly sus­tain itself off of rain­wa­ter and snowmelt in the spring. 

Since this prod­uct was designed in Vir­ginia and our cli­mates are fair­ly sim­i­lar, Nashville is a per­fect place to use a tree dia­per. In a sce­nario where no rain­wa­ter falls, the tree dia­per doesn’t dry out for about 45 days, mak­ing it very drought resis­tant. But a tree dia­per doesn’t just help water a plant. It can also pro­tect the plant from a vari­ety of envi­ron­men­tal factors. 

What Is in a Tree Diaper? 

The orig­i­nal pro­to­type for the tree dia­per actu­al­ly was made from recy­cled dia­per mate­ri­als. The poly­mer includ­ed in dis­pos­able dia­pers is a high­ly absorbent mate­r­i­al that is used once and winds up in land­fills across the coun­try. Part of the inven­tors’ mis­sion state­ment was giv­ing a sec­ond life to these high­ly use­ful poly­mers that can dry and recharge for years, keep­ing them from being dis­posed of too ear­ly. The poly­mers in the tree dia­pers you can buy now are made from new mate­ri­als, because many cus­tomers were not too fond of the con­cept. Though there was noth­ing unsan­i­tary about recy­cled dia­pers, it was a hard sell for the inven­tors. Their goal for the future includes using more recy­cled prod­ucts, with the hope being that the product’s effi­ca­cy out­weighs the gross-out fac­tor of ​‘recy­cled diapers.’ 

How the Tree Dia­per Is Being Used on Shel­by Ave.

Now that we’ve explained a lot of what the tree dia­pers do, you’re prob­a­bly won­der­ing what they’re specif­i­cal­ly doing for us at Shel­by Avenue Arbore­tum. While they aren’t designed specif­i­cal­ly for road­side arbore­tums, there have been case stud­ies con­duct­ed on tree dia­pers in Vir­ginia, where the tree dia­pers went mul­ti­ple years with­out water­ing or recharg­ing by irri­ga­tion sys­tems or hoses. In the study, road­side trees in Rich­mond, Vir­ginia were sup­plied with tree dia­pers that were then cov­ered in mulch. Over the course of mul­ti­ple years, through two severe droughts and rough win­ters, the tree dia­pers kept all of the trees alive and thriv­ing with zero maintenance. 

So, tree dia­pers are not only great for trees — they also great­ly reduce the need for water­ing and con­struct­ing irri­ga­tion sys­tems. Con­serv­ing water and being able to rely on pre­cip­i­ta­tion exclu­sive­ly is a great way to make sure the arbore­tum is good for the environment. 

Because the arbore­tum is locat­ed beside major streets in the city, there are risks that the tree dia­per can help mit­i­gate. They act as a phys­i­cal bar­ri­er between water runoff, which could be high in pes­ti­cides or salt from lawns, side­walks, and the streets them­selves. While many of the trees at the arbore­tum were select­ed for their resis­tance to such envi­ron­men­tal fac­tors, the tree dia­pers are a good extra line of defense. Oth­er phys­i­cal dam­age like land­scap­ing and traf­fic acci­dents can be kept at bay by a tree dia­per. They aren’t tall, but they can act like an airbag between a weed wack­er and a tree trunk in the right situation. 

Ten­nessee weath­er is no pic­nic. We have hot sum­mers and have been expe­ri­enc­ing some mem­o­rably cold win­ters. Extreme weath­er often pos­es risks to irri­ga­tion sys­tems. For exam­ple, water­ing bags are the low­er-tech pre­de­ces­sor to tree dia­pers. These water­ing bags are used by many munic­i­pal­i­ties for man­ag­ing the irri­ga­tion of urban trees and plants. The risks asso­ci­at­ed with using water­ing bags are hard to bal­ance with the reward, how­ev­er. Besides under­per­form­ing at water­ing when com­pared to the tree dia­per, water­ing bags also absorb heat. When this hap­pens on a hot and sun­ny day, it can actu­al­ly raise the soil tem­per­a­ture by sev­er­al degrees, effec­tive­ly cook­ing a tree’s root system. 

The tree dia­per does not have this prob­lem. They can and should be cov­ered in mulch when used on a tree, mak­ing them effec­tive­ly invis­i­ble. This also pre­vents them from absorb­ing much heat and rais­ing soil tem­per­a­tures like water­ing bags. In the win­ter, on the oth­er hand, tree dia­pers are also well-adapt­ed to deal­ing with below-freez­ing tem­per­a­tures. The tree dia­per freezes and thaws with­out dam­ag­ing the inter­nal or exter­nal com­po­nents of the sys­tem, mean­ing it can stay out year-round. In the win­ter, it acts as a heat sink, keep­ing the soil tem­per­a­ture high­er than the sur­round­ing air. In one study, the soil at 3 inch­es deep remained at a sta­ble 40 degrees, while air tem­per­a­tures dipped into the sin­gle dig­its. This is huge for keep­ing decid­u­ous trees healthy in win­ter, aid­ing them while they’re dormant.

So if you’re still won­der­ing after all this: do tree dia­pers work? The answer is a resound­ing yes, and we’re already see­ing first­hand results with them at Shel­by Avenue Arbore­tum. The trans­plant­ed trees that use them are rely­ing on almost no human inter­ven­tion in terms of water­ing, mak­ing use of rain­wa­ter and snowmelt. They have helped our trees already sur­vive a very dry sum­mer and an extreme­ly cold win­ter. And the best part is, they aren’t an eye­sore. Because they’re meant to be cov­ered by mulch, you prob­a­bly haven’t even noticed them when dri­ving or walk­ing by. We’re proud of the mis­sion state­ment of the tree dia­per focus­ing on sus­tain­abil­i­ty and con­ser­va­tion, as those are two pil­lars of our work here in Nashville. 

Still not sold on the con­cept of the tree dia­per? Take a trip to Shel­by Avenue Arbore­tum and see the spring­time buds and flow­ers for your­self. These trees are almost all using tree dia­pers for all of their hydra­tion needs, sav­ing tax­pay­er mon­ey and keep­ing water in our reser­voirs for drink­ing. Want to learn more about tree dia­pers or how you can help the ongo­ing effort at Shel­by Avenue? Give us a call or send an email our way; we’d be hap­py to share even more.