Practices With Tree Spade

cacau

We need to relocate five or six trees around 2 to 3 in. dbh and 12 to 15 ft. tall on a campus. A tree spade is being brought in to do the job, not sure what size spade offhand, maybe around 40 in. Trees are Juglans cinerea, J. nigra, Parrotia persica, Pterocarya x rehderiana, and Hibiscus syriaca. Soil will be the same where they'll go in as where they'll come out; fair amount of clay, neutral to slightly alkaline. My question regards preparation of the new planting holes to encourage better/faster regrowth of severed lateral roots. Is it typical for contractors to use the spade to create the planting hole and then drop the plug with the removed tree right into it without doing any "roughing up" or soil decompaction at the new site? This would seem to be contrary to usual recommendations for planting B&B or container stock. Anyone have any general guidelines for site preparation in situations like this?

Cacau

pcarborist

Cacau, I would "rough-up" the sides of the hole dug with the treespade especially if you have clay-textured soils due to soil glazing. The other thing you want to do is compact the soil very well around the rootball to force all the air pockets out. A combination of handwatering and compaction works well. Make sure when you water the newly planted tree at the rootball/new soil interface. Studies show that roots dug up with a tree spade can take up water like a sodastraw, that is they don't completely suberize. A 40" tree spade should be fine. The rule of thumb is 10" rootball width to every 1" basal diameter, so you could actually go down some what if you wanted to.
k

ronnyb

Definitely rough up the sides, the spades will glaze them up. Another thing to watch for (and this will take a couple of months) is that a gap tends to open up between the ball and the hole. Almost every tree I've planted with a spade has done this. Some times it a couple of inches, other times its a couple of feet of the diameter. You'll have to add topsoil to fill in the gap or hand dig down to take care of it.

Eric Frei

Sandy loam washed in would work a treat?

__________________

cacau

Thanks for the replies, folks. Roughing up the sides of the planting hole sounds very important in case they get polished from the spading. I wonder how important it would be to do the same with the rootball edges...probably not as much, and the rootball may not be accessible anyway during the transplant until it's dropped in the new hole. I notice nobody has advised enlarging the planting holes laterally to decompact the soil especially in the top 18 inches or so. For six trees that would be a good bit of work, of a type a lot of people don't like to do! In any case, I will be on the lookout for soil subsidence around these transplants over the next three to six months.

Cacau

Eric Frei

I'd certainly say decompacting (if req'd) the vicinity.

When we put in some large poincianas with a bobcat I made the hole twice the size and got a 50/50 mix happening of the original soil and new sandy/loam/garden mix. Also the new hole was a little deeper and we filled the bottom with rubble and same 50/50 mix. Hate to have a well of water drown the tree, was clay soil. Trees are fine, grew like buggery.

We roughed up and made the mix with the backhoe bucket excavator thingy.

Nice mulch ring on top. Trees actually finished up maybe 2" above grade on a slightly domed top with 3m dia mulch circles.

__________________

mdvaden

Once dropped in, if it was mine, I'd consider digging 1/2 to a full shovel's depth from around the rootball, outward about 8" to 12".

Then loosen that, and backfill that circular trench after washing a fine loose blended soil in any gaps.

And about 3" of medium / coarse mulch on top except right near the trunk.

You have the names detailed quite well. Did the campus catalogue it's trees courtesy of the horticulture department?

newguy18

Whatn is a tree spade?I've never heard of one but then again I haven't planted any good sized trees or relocated them.

__________________
Have your say join us today.


old schooler

Sean Freeman

Check out this short piece on tree spade being used in uk AIE - TrunkLine - Tree Spade it'll help explain and show some of the advantages and illustarte some of the drawbacks pointed out by others here.

newguy18

Thanks Sean.

__________________
Have your say join us today.


old schooler

DRANO

you should loosen soil at spade site,also make sure base it at correct height for root ball,tampen soil aty base,hard and not good to set it in and keep pulling out till you get it right!!also check for compaction of ball,if trees are done same time out and transplanted at same time you should be fine.remove any problem roots while out make sure you have nice clean sharp cuts,it doesnt hurt to spread your l;aterals so your tree will be able to secure it self as quickly as possible.wrap ypur root ball with a piece of loose canvas and keep moist while in the free air does not take as long as some think to start damage.,if you need to stake do so correctly and for the least amount of time as ness.a tree that size set right and lightly tamped into place really doead not need to be staked unless enviorment or foot traffic and hazards call 4 it.water,water,WATER!! AS needed.good luck drano: