Tree planting auger size?

   / Tree planting auger size? #1  

Dadnatron

Veteran Member
Joined
Mar 24, 2016
Messages
1,113
Location
Versailles, KY
Tractor
JD 5100e with FEL
I currently have an FEL mounted Danuser hydraulic post hole digger. It works great, albeit a bit slow off my 3rd function system for grapple. I have an 8" post bit, but it is too small for trees.

I've been looking around for a couple larger bits, hopefully used, and have seen a few at auctions. I've bid, but lost out... mainly due to apathy of a specific purchase.

But now, I'd really like to find at least one perhaps 2 bits. I just planted 22 trees and had to rent an 18" bit, which worked great. But it was $90/day. I'm not enough of a planner to have everything laid out for a big 'hole drilling day'. I typically find a few trees that I'd like to plant and purchase them, so I need a bit on hand to put them in.

I'm looking for your opinions on the most versatile sizes of tree/shrub planting bits. I've looked at the big conical bits that are shaped like an upside-down Christmas tree, and thought that would be great. However, I'm concerned that a larger diameter hole would be too deep in the center, and would create a hollow under the tree ball, even if I backfilled. (Any experience with these types of augers would be appreciated.)

I've been thinking about getting an 18" and a larger 30, 36, 42" for larger trees. When I buy a larger 3" tree, from the nursery... I need a bigger bit or I'm huffing with a shovel. But... with bigger bits is bigger $ and I am unsure about utility overall. I'm also uncertain about the HTF style bits from McMillan. (Have a smaller bit then the large bit about 10" higher. I don't know how or what this is used for or the benefits, although I can see a couple perhaps.)

What are your recommendations given the above? I will have far too many trees to plant over the next few years to do it by hand... at least I am unwilling to do so.


Auger bits.JPG
Auger bit conical.JPG
 
   / Tree planting auger size? #2  
Back in the day - mid '80's - we could buy young trees from the forrest service. Fruit, ornamental and evergreen. Usually the smallest lot size was 25 trees. So.... being new to this much property we purchased hundreds - all flavors. These all were very small - about two feet tall. They were dirt cheap.

Soon realized that planting 300 - 400 small trees with a manual post hole digger wasn't going to happen.

Borrowed the neighbors old PTO post hole auger. It had an 8" or 10" bit. Auger down three holes in a triangle shape. Didn't even need to move the tractor. Clean out the hole with the manual post hole digger. It was a God sent help. I could move and auger the three holes - clean out the hole - the wife would be ready to plant another tree.

If we could have had only one auger - probably a 16" or 18" would have been ideal.
 
   / Tree planting auger size?
  • Thread Starter
#3  
While I have no desire to put in that many trees, I did just order 70 seedlings of various varieties. I have absolutely no desire to dig by hand. Obviously the seedlings wouldn't require as much digging, and my current 8" bit would address the hole, but I really liked the way the 18" bit cleared the sod around the hole and loosened up the soil a bit. I only went about 8-10" deep, just enough to clearly cut the sod off and loosen to a small depth. So I don't believe they should settle into a deep hole. I've heard horror stories about seedlings sinking 2-3' due to overzealous post hole depth.

I'm thinking that at a minimum, an 18" would be useful, as I could also use it for putting in piers for buildings. (although on some, it would be overkill and perhaps cause me to require too much concrete.)
 
   / Tree planting auger size? #4  
My 12" auger will wallow-out a good-sized hole but I never used it in planting the 18 fruit trees I have. I used my Craftsman rear tine tiller and man-handled it to make a larger diameter "hole" maybe 18" deep max. Worked well for me.
 
   / Tree planting auger size? #5  
I use a Backhoe- had to dig out 7' by 3' deep for new larger tree, and remove old stump.
Took me < 30 minutes. Any rentals or neighbors that have one?
 
   / Tree planting auger size? #6  
I helped plant 400 knee-highs on a Saturday and another 300 the following day 20 or so years ago, pine and spruce. I spaced and dug with a round point shovel and the pal would stuff the holes. They'd back-fill while I'd cup and mulch where pine straw was handy. Both guys hated me for ordering so many after planting, but not being able to water them 'in' or later I suggested a 25% survival rate. Of the four hundred we lost at most 1/2 ac (~1/4 of) in the two ac we planted. Of the 300 I doubt 50 survived.

It all depends on size of the ball & hole. I wouldn't want a hydro-motor that didn't breeze with an 8" auger to have to muscle 16" or larger w/o changing the motor and expecting to go slower if gpm was limited. The bigger & the fewer the more I'll spend getting the holes right, say mixing in silica gel or phosphorus, etc. Multi-holes are a nice shortcut in tough soil. Back-hoe or mini-ex is your friend if rented and all holes can be popped in one day.

Here I've only planted 175 whites (18 yrs ago) and due to size I now have Skidder with tree spade to move them farther apart. That's another thing I'd consider hiring done if buyng enough trees from the same source & available. I had 14 7-10 spruces planted at my old house 25 yrs ago and the guy brought/planted them & three deciduous the same day. Spade was on the back of a truck and I rode back & forth to choose my trees one at a time. btw, Evergreens are easy. Oaks & Hickories not so much.
 
   / Tree planting auger size?
  • Thread Starter
#7  
If I need, I will simply change out my short 3rd fnct connections and run long hoses to my rear remotes which have significantly more flow. I'm not concerned with the power to run a larger auger bit.

In the last day or so, I have seen that there is an HTF labeled auger with an almost 2 stage bit. The first portion is roughly 18" and the second larger part is from 36 to 42". This would allow me to put in smaller, more shallow holes but also larger holes for bigger ball trees.
 
   / Tree planting auger size? #8  
We just planted 700 seedlings with a tree spade
 
   / Tree planting auger size? #9  
Planting bar/dibble or 'tree spade'? I've used both.

 

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   / Tree planting auger size? #10  
FWIW: When I learned to use a planting bar, a forester gave me a tip that after inserting the bar vertically in the soil, one should only move the planting bar to one side. That way, you can step on the soil wedge side and press the soil back in contact with all of the saplings roots. Moving the bar back and forth was said to create an air pocket that was difficult to remove.

I don't know if it is true, but I followed the advice and we didn't lose any trees.

Anyone else have tips?

All the best,

Peter
 
 
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