Rethinking the Way We Plant, Part 2
April 9th, 2013
I was reading some old gardening books lately and was dumbfounded by how so much planting advice is now just the opposite of what was the “expert advice” just a generation or two ago.
It makes me wonder what experts are going to be saying a generation or two from now. Did we get it right this time? Or was the earlier advice on planting a tree or shrub right after all? Or maybe both we and the oldsters will turn out to be morons by 2050.
Last week I told you about some of the new thinking on dealing with the alleged soil at the planting site. Here are eight other planting steps that, at least for now, are supposed to be the right ones:
1.) Skip the high-phosphorus fertilizers that supposedly encourage root growth. Just go with native soil and water, and if anything, a little nitrogen fertilizer, such as fish meal or fish emulsion.
2.) Remove all burlap, twine, baskets and any other packaging material from your new plant’s roots before planting. In fact, some are recommending to even remove the soil in the pot and burlap bag so the roots go right into the new soil (see last week’s post).
3.) Locate the point low on the trunk where the trunk flares out and transitions into the root zone. Then make sure that point stays slightly above grade. This “root flare” or “shoot-root interface” should never be buried. Be aware that it’s sometimes already covered by soil in the nursery pot or burlap bag.
Find where the base of the trunk begins to flare out into the root zone and make sure that point is just above grade.
4.) Don’t prune off the top growth to “bring the branches into balance with the roots.” Only prune off broken branches at planting. The top growth is what will produce the energy that the roots need to grow, so lopping them off reduces the plant’s energy “factory” right off the bat.
5.) If you’re planting a single tree or shrub, build a berm around the hole’s perimeter to guide water into the root zone.
6.) Stake lightly, if at all, and only for the first year. Attach the supports about one-third of the way up with soft materials that won’t cut into the bark. Letting the trunk sway a bit encourages the roots to establish quicker.
7.) Wrap wire cylinders around the trunks 2 to 3 feet up to prevent rodents from girdling the tender, young bark and killing the whole plant after you’ve done everything else right. Animal damage is an underrated cause of plant loss in our rabbit-, vole-, chipmunk-, mice- and deer-infested area.
8.) Keep the soil consistently damp but never soggy for at least the first full season, and your odds will get better day by day. Soil moisture is especially critical in those first few years.
Do a good job with all of these, and when your new maple is still alive in 2050, no one can say you were a total moron.
Great article George! Number one cause of new tree planting decline is improper planting depth (Buried trunk flare)in my opinion.
Bob,
I’d agree with that. Planting depth is underrated. Some people purposely plant deep because they think the tree will be less likely to blow over. That’s burying, not planting.
I’d have to rate water issues as No. 2 on the tree-killing list — sometimes too much but usually not enough.
Have a great season trying to replace all of those trees we’ve lost in the past couple of years.
George
Good solid and accurate advice.
The only thing I would add is to not freak out if you planted a tree a little deep. Research presented at the 2012 Urban tree growth conference at the Morton Arboretum found that planting the root crown say up to 4 or 5 inches under grade did not significantly impact the health of urban planted trees. That being said, at or slightly above grade is better and planting the flare deeper than that DID impact tree health.
Jim
Hi Jim,
Hadn’t heard about that Morton Arboretum report. That goes against the grain of most every opinion I’ve heard from arborists in the last decade or so, namely that planting too deep is the No. 1 cause of tree death. I’ll have to check that one out and see what the researchers might’ve speculated as to why they didn’t see serious trouble. Thanks.
George
Hi George,
Planting too deep WAS confirmed as cause of decline and early tree death (as well as trees just not growing any larger). Sorry, I didn’t mean to imply that it was not. It was just that for that small amount of 4-5″ too deep didn’t seem to impact shade trees. Just the process of digging B&B trees can pile that much soil on top of the root flare area. Most trees are planted WAY DEEPER than that and those definitely do decline and die prematurely.
Also this was for shade trees, a shrub planted 4 inches below the crown depth will definitely suffer. The research DOES support that planting the flare deeper than 4-5 inches WILL cause decline.