2x2 trees sometimes fail to grow, but if they grow, they always grow on the surface

I can confirm. Doesn't happen in all locations and can sometimes be fixed by removing blocks next to it. Might be related to MC-179952.

It seems like this issue only happens when you create a 20w16a world and then load it in 20w17a. If you create the world and stay in either one it works fine.

I can confirm what Chase said. I tried creating a world in 20w14b and reopening it in 20w17a – same thing. A world created in 20w17a does not have this issue.

This isn't a complete topic match, but I also noticed some changed behavior compared to 1.15.

2x2 trees won't grow if there is any block above them at any range (e.g. 50 blocks above), even transparent blocks like signs/glass/water. Removing all blocks directly above the saplings allows them to be grown again.

In 1.15 they can easily grow under the same conditions.

I have had the issue when starting a world in 20w16a and then updating to 20w17a.

I was having this problem with a 20w16a --> 20w17a world. Appears that if I break the dirt blocks underneath the saplings (I've been breaking a 4x4 swath, just in case...), and then replacing the hole with the same dirt backs, the same saplings will grow. Seems to reset some property on the saplings and/or the dirt that's changed in the latest snapshot...

Also, from my (accidental) duplicate ticket, these saplings won't grow regardless of how the saplings are acquired (/give, Creative or naturally) with dirt/grass acquired through any of the same means, regardless of tickrate gamerule or bonemeal.

Furthermore, tested with a 1x1 setup just in case dark oak saplings were receiving an unannounced change, with no success. All tested in single player only.

I have the issue on a 20w17a server, and world also started on 20w17a

This seems to be related to the height map issue mentioned in the first comment (see MC-179952).  Placing the northwest sapling into a spot for which the debug screen shows good height map values allows the tree to grow, even if the other three saplings have bad height map values.  With a bad height map value for the NW sapling but good values for the other three the tree does not seem to grow.

Snapshot 20w18a restores the ability to optimize a world, and that process appears to correct the corrupt height map data.  Trees are growing again, thank you!

Happening to me in a newly made 20w18a world.

Accidentally made a duplicate issue.

I've optimised my world for the latest snapshot but needless to say they still wont grow for me.

Yeah, I forgot to check "clear cache" when optimizing. When that one's checked it worked.

@PappaDavid worked for a singleplayer world or server world?

I downloaded a serverworld and did it in Minecraft, then uploaded it again. So, yes on both accounts I guess.

In 20w18a dark oak and jungle now work.

2x2 spruce tree still not working 98% of the time.

Might be related to / the same issue as MC-164143 was?

@bugsbugsbugs still working for you? I can only reproduce this on Creative, but on Survival it doesn't seem to work.
Might be the random tick tricking me but I used a couple stacks of bonemeal already on a single tree and it doesn't grow.

I am seeing this issue on 20w18a. Server world was created on 20w11a, upgraded to 20w16a -> 20w17a -> 20w18a. Multiplayer. Just planted 4 jungle saplings in the same chunk on grass blocks with no obstructions near or over them (although when I looked up, there were clouds at that moment). I'd been building for several minecraft days when I ran out of wood and noticed none of my trees had grown yet.  I used 64 bone meal on them to no effect. After reading PaulK's comment above, I broke the dirt blocks underneath and fed the saplings 48 bone meal. Still no growth. 

I farmed some bone. I took 10 stacks of bone blocks with me and dropped 4 more stacks of bone on the trees, one on each sapling in the 2x2 grid just in case.  Just in case it was relating to neighboring blocks, I mined out the 12 surrounding grass blocks and replaced them with dirt and repeated the process - 1 stack per sapling. I then uprooted 3 of the saplings to test the single sapling in isolation, and the second bonemeal caused it to sprout into a tree.  I am starting to wonder if it's the saplings themselves. I'll get some new saplings (not from before the upgrade) and verify with them.

@Jason Mayer and all,

It seems it has to do with the height map issue linked. I had this issue yesterday on 20w18a, from a world converted from 17a from 16a, and it got fixed on 18a after I optimized the world.

How do we do that on a server, my friend isn't sure where to see that in mineOS

You can take a look at MC-179845 for instructions on how to optimize your world, no matter whether it's singleplayer or multiplayer.

Please report back if optimizing the world does not solve the issue.

Optimization does not fix my spruce tree problem (single player world created in 20w08a that has been updated through all snapshots, and on a new world created in 20w18a). You can see the minimal spacing that is needed for me to grow a spruce tree in (MC-181600).

I did not see tree growth with just --forceUpgrade, it looks like both  --forceUpgrade and --eraseCache were required.  Thankfully, this does fix the issue on 20w18a! Thanks 🙂

I tried my world in single player and on a server. Optimized from 1.15.2 to 20w18a. For me, it seems dark oak saplings will grow with bonemeal when they are exposed directly to the sky. I have a tree farm underground, and those trees have stopped growing altogether and will not grow even after using a full stack of bonemeal on 1 sapling. When taking the same saplings from my underground farm up top into my plains biome right above my base, the saplings will grow when bonemeal is applied. Still an issue for the underground base.

@Jon Whisman, I can confirm this underground not growing behavior. Even transparent blocks or special objects like signs prevent the growing if they are above the sapplings at any distance (even 100+).

@Mods, could we get an extra ticket for this issue? Or at least adding it to the description of this issue. Because I believe, preventing trees from growing underground is definitely a bug and not expected behavior.

Was able to reproduce this myself in a brand new world. Video:

.

The ticket's description and summary have been adjusted.

Edit: I initially assumed the trees weren't growing due to the blocks next to them. Turns out that isn't quite true, and I don't seem to be able to see any pattern in that regard.

The user in MC-179909 suggested that it depends in which version the chunk was first generated, more info in that ticket.

F for ilmangos dirt farm, now that it's fixed.