Planting bareroot trees and shrubs the French way

03/12/2009
Planting bareroot trees and shrubs the French way

It's early spring, a season which for much of my life has meant planting bareroot trees and shrubs.  And yet it took moving to France for me to learn the single most important trick to being sure that my bareroot plants get off to a rapid, vigorous start.  Have I piqued your curiosity?

But before I reveal the secret, let's get back to the basics.  In order to understand how to plant bareroot stock successfully, you first have to understand just what a bareroot plant is.  To sum it up in a single word, a bareroot plant is vulnerable. 

Here's why.  Your bareroot shrub was nursery grown.  Then, once it went dormant in the fall, it was dug up and the earth shaken off its roots.  Of course, when it was dug up, it lost all its fine feeder roots as well as a lot of its fibrous roots.  Then the plant probably had some of its branches pruned back for easier handling, and was put into cold storage under controlled humidity for the duration of the winter.  When you ordered the plant to be shipped to you, it's roots were wrapped in some kind of moisture-retaining material, then the whole plant was wrapped in plastic, stuffed in a box, and shipped to your doorstep.

Therein lies one of the great advantages of bareroot stock:  enabling you to mail-order plants from far away without prohibitive shipping costs.  Another advantage is that bareroot plants are always much less expensive than container-grown ones.

But now, back to their disadvantage:  bareroot plants are fragile!  They have lost half or more of their root mass; they have been held in a sort of artificial hibernation for months; and now, you are unpacking them into bright sunlight and fresh air.  That "fresh air" is the biggest danger to the survival of your bareroot plants.  For a whole number of reasons, they are terribly susceptible to drying out.  Remember, for months they have been held in an artificially humid environment, which has prevented them from drying out.  Plus, even once you get them planted, their reduced root mass handicaps them in absorbing water.  So, all the strategies I'm going to describe are aimed at minimizing dessication of your new plants.

If you're going to be able to plant within 48 hours of receiving your plants, keep their box unopened in a cool place, such as an unheated garage or the north side of your house (if above freezing).  If you need to hold the plants for longer, open the packing immediately and heel the plants in by laying them at a 45-degree angle in a trench, covering their roots and half of their stems with fine soil, and watering thoroughly.  Your heeling-in spot should be out of direct sun and protected from wind.

In Provence, we just got through planting a very long (250-foot long) tapestry hedge consisting of bareroot hazelnut, quince, corneliancherry dogwood, and smoketree--all knit together with heirloom climbing roses.  I'm going to walk you through the process of bareroot planting via the example of this hedge.

The first step in successful bareroot planting is to thoroughly prepare the soil.  In our case, this consisted of using a backhoe to dig a trench 2 feet deep along our 250-foot roadside. We then laid 8 inches of rotted sheep stable manure in the trench, and covered that with a layer of finely crumbled soil.  This trench method is perfectly adapted to the planting of a hedge, where plants are spaced only a yard or less apart.  However, if you are digging individual holes, make sure they're twice as wide as the spread of your plants' roots.  Add compost or manure to the bottom of the hole, along with some finely crumbled soil to make a cone-shaped mound of soil over which you will spread the roots.

The addition of compost or manure will provide a rich and friable environment for your plant's new roots as they grow and take hold.  Plus, as the organic material continues to break down, it will provide a long, slow feed to your plants.  You may add some bonemeal or rock phosphate as an extra phosphorus source to stimulate root development.



Well-rotted manure is also a component, along with the sticky clay (below  right), of...drumroll...pralin, the French secret to superlatively successful bareroot planting.  No, I'm not talking about a hazelnut-filled chocolate here.  Pralin in the French gardening world is a slurry of rotted manure and clay mixed with water.  That said--like me--the French are always thinking of food, and this lumpy brown mixture bears its name due to its resemblance to...praline, the confection of caramelized sugar and almonds or hazelnuts. 



We took advantage of a mason's  tub to mix a super-sized batch of pralin.  That's my helper, Liseron Fleury (with a name that translates as 'flowering morning-glory, he's got to be a gifted gardener, right?) and the indefatigable Rémy Arnoux, son of my neighbors Jean-Claude Arnoux and Agnès Ladret (of My Neighbor's Lamb fame).  Rémy, age 13, does the work of ten men, and does it with joy, competence, and confidence.



That's Rémy handling the small tractor every bit as competently as his dad.  What a beautiful sight in a world of thumb-twiddling Gameboy players!  Conveniently, the mason's tub was filled with rainwater, so Rémy and Liseron just added enough manure and clay to make a soupy slurry that would cling as nicely to the roots of our plants as the coating on a chocolate-covered almond.




This capacious tub was ideal for our big planting of 80 shrubs.  But for a smaller planting, you can mix up a smaller recipe of pralin in a five-gallon bucket.  Your bareroots should be left to soak in their mudbath for at least 2 hours, and up to 24 hours, before planting.  After this long soak, they will be fully hydrated, and their roots will be covered with that all-important, tightly adhering coating of clay and manure. 

This coating not only prevents the roots from drying out while the plant is waiting to be put in the ground, but also helps bind the surrounding soil to the newly planted roots.  I can testify that the results are well-nigh miraculous speed and vigor of establishment.





It's best to keep your bareroot plants in the pralin bath until the moment of planting.  Our mason's tub (made of steel and too heavy to move) was at some distance from our planting site, so Liseron put several pralin-filled buckets in a wheelbarrow, placed enough plants in them to keep him working for an hour, and hauled them to the planting site.  Then, he removed each plant one at a time, when he was ready to plant it. 

Now that you understand how to practice the fine art of pralinage, let's move on to the next important point in successful bareroot planting:  backfilling the planting hole.  Most people do this by just shoveling the chunks of soil they dug out of the hole back in.  No, no, no!  Do I sound like your mother?  Are you paying attention?  Because now that you have your plant in the ground, the greatest danger to its survival are air pockets--large or small--in the soil around its roots.  Once more, remember dessication is the greatest risk for your bareroot plant.  Air pockets around the roots mean that they won't be able to take up crucially needed water, and that your plant will languish or die.

That's why we took the time to get down on our knees and use hand hoes to finely crumble the soil as we dragged it back down into the trench around our plants' roots.  Big clumps of soil won't settle firmly around the roots even with copious watering.  And don't--repeat, do not--use your foot to tamp the soil around the roots, as is so often advocated.  Doing so is likely to injure them.



It's difficult to make out the slender branches of the newly planted shrubs in the photo at right.  That's because we've pruned them a lot before planting.  It's better to err on the side of too much pruning than not enough on bareroot plants.  Too much top growth for the diminished roots to support is a sure death sentence for your plants.  And finally, pay careful attention to planting depth.  With the exception of grafted roses, bareroot shrubs and trees should be planted with the crown--the point where the roots begin--just below the soil line.  (Grafted roses should be planted with the graft 2 inches below the soil line.)  Too high, and the roots will be exposed to the air and dry out, and too low, and the roots won't be able to "breathe."  Lay a shovel or other tool handle across the hole as you set the plant to verify were the soil line is.

Finally, the job isn't over until you water, water, water.  Use a gentle stream of water to saturate the ground around your new plant repeatedly.  The water, besides being vital to the plant, serves to close up tiny air holes around the roots (tiny, because you finely crumbled your backfill soil, right?).  Verify the planting depth of your plants after watering them in.  If you really crumbled your backfill, it shouldn't have changed.  Keep the soil moist until the plants leaf out, and continue to coddle them in their water needs throughout  the first growing season.

A planting on this scale wouldn't have been possible for the weekend gardener that I am without the incredible help of the ever-present Provençal gardian angel, Jean-Claude (perched in his backhoe at left ), his wonderful companion Agnès, shepherdess extraordinaire who heeled in my plants in my absence as lovingly as if they had been her own, their son Rémy, a prince among boys, and the wonderful Liseron and all his painstaking care.  Huge thanks  to you all!

Did you notice at the beginning of the article that I referred to this planting as a tapestry hedge?  I'll get back to you in a couple of years to show you what this random mixing of hazelnuts, quince, old climbing roses, corneliancherry dogwood, and smokebush looks like throughout the seasons.  For now, these slender twigs hold only the promise of the flowers, fruits, nuts, colorful fall foliage and winter berries to come.

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