Cottonwood here strings to the point where it is a "full cycle" wood with a hydraulic splitter. Add to that it is "woof" wood once you get over half of it's weight out (drying), I avoid it. Easiest: Poplar and Walnut are the easiest. Bitternut Hickory and White ash have been butter too for me. Worst: Obvious Elm but the worst we ever had a was hard maple. I don't know if it was some kind of Christine tree or what but it broke Dad's splitter 3 times. We even cut a couple 24 inch long rounds in half and still stalled on straight grain pieces. It actually sheared crossgrain easier than with the grain. Weirdest thing I've ever seen in over 40 years of working wood. You couldn't even start a wedge in it as it just popped out, even a razor sharp one with slow taper. I plunge cut a 12 inch round with a chainsaw and put a wedge in, still popped. Dad was bent on winning but finally gave up and noodled it.
Thats for sure. Cottonwood I started out with ranked right up with elm as hardest Ive split. Linden has been my easiest.
My wood comes from tree guys so it is almost exclusively yard grown. Although certain trees are usually easier it is hit or miss even within the same species. For every nice splitting log I can tell you about one that wasn't too easy. Start getting wavy grain and it gets more difficult. All bets are off if you get a corkscrew grain. Maple seems to be the best at growing like that. Hidden knots are killer too. I've had clear looking 24"+ oak logs that one busted into you find that they had lots of lower branches that were pruned off 30-40 years ago. What should fall apart into nice blocks takes every bit of effort to get apart with the hidden knots. But without yard induced variation, oak is generally the easiest and sycamore or shagbark tend to be more difficult.
Straight grain red oak is the easiest. A tap with the maul and it falls apart. Generally speaking elm and gum are the stringiest, but anything tree can grow with a twist or curl that makes them damm near impossible to split by hand. A lot of the hedge trees I cut have an interlocking grain (lace your fingers together and you'll get the idea). They don't split apart...they tear apart.
I split all by hand too. The worst for me have been yard trees. Stringy stuff like poplar and elm can be tough too, but nothing like that corkscrew grain. At least you can make progress with stringy stuff - the axe will bounce right off the corkscrew stuff, and you can't even start a wedge in it - spits it right back out. I've found the stringy stuff is easier to split when it's dry. A sharp axe can also help *tremendously* for cutting through those fibers. I've never had a problem splitting elm, but it's all been from standing dead trees with the bark falling off. The aspen poplar I've done has gone both ways - if it's green and not rotted, it's really stringy; but most of the fallen stuff is rotted and pops right apart. No EAB here yet - I have plenty of thick, healthy stands of it - and it dominates the low spots that have standing water all spring. If you don't have any, it may have been a green wood burner that cleared it out, not the EAB. A lot of people will burn it right off the stump. "...But Ashwood wet and Ashwood dry, A King can warm his slippers by."
Around here my favorite is red oak, least favorite is elm. Like many others I split by hand, 4 to 5 cords a year. No matter how big the red oak round is, it always seem to split with such a energetic "crack" sound. Smaller rounds take one swing with the maul. Larger rounds take a couple, start at the far edge and slowly work towards the center in a straight line 'till it pops. As long as I can get red oak I will not be buying a splitter. KaptJaq
I get a lot of Wavy grain trees too. No rhyme or reason and can grow right next to an easy one. here is a couple pics of some Beech that way. wedges just pop out and you'd pound your brains out trying it with a maul. maul just bounces as well.
Around these parts, soft maple, white ash, red oak, popple and bass are the easy ones. Elm is in a category all by itself. Pin oak can be tough to split sometimes.
Seems like the preferred splitting wood is oak or ash. And Elm and Gum with yard trees being in a class of their own.
After splitting manually for 34 years for me its still straight grained Red/Black Oak the easiest,most all American Elm (White Elm) the toughest by far,especially when green. Most Silver Maple is very close to Red Oak. But very large Silver Maple yardbirds can have very stubborn wood,with all the twists & turns. Most any large log (even straight/knot free) from old Apple trees is quite stubborn because the way they grow when in open area.Gnarly old Honey Locust,Mulberry & Shagbark Hickory crotches/knotty trunk sections are the toughest wood I see on a regular basis.With the occasional open-grown White or Bur Oak. Some Silver Maple with moderate curl/cross grain
Straight sugar maple is a pleasure to split. 31 inch rounds split like butter. But some other sugar I have just given up on...wavy , gnarly, great wedges just bounce off. After being stubborn with wedges and a 10 pound sledge, I had a very sore arm and only half a round split. It and it's siblings are sitting waiting for the rental splitter. Twisted grain maple is even worse than spiraling ironwood. I may try the round if it gets down to 8 or so F during the day, and the splitter hasn't yet been rented...just to see how freezing effects things. Darn, I'm dumb and stubborn.....
I find any wood than that is green and straight grain is easy to split. The hardest wood to split is dry round. Dry round of locust is a shoulder buster.
I loved splitting cherry and red oak by hand this summer. I have not had such luck as others have with ash. I found it to be stringy. The little rounds are good, but the trees I ran into were grown in the open and did not split easily. So, the splitter was brought in for that work.
