For the Hoard achievement

[Nutella]

Keep doing the space missions, eventually you will get it, right?  Unless your game is bugged ... lol

The death flower doesn't look like its added to the gardening collection set.  My set still shows 31, Carl's list has 32 plants (plaintain doesn't count), so the death flower is definitely not added.

[ClayMask]

I've only got one space rock to go but can't seem to get it.  I think it's the overly large space rock.

If you're interested in reading about what to choose to get space rocks, there are quite a few choices you can make posted here:  http://www.carls-sims-4-guide.com/forum/index.php/topic,21226.0.html

Or you can just do the space adventures and discover what works for yourself.

[Nutella]

Gardening grafting is fixed, this achievement is doable now.

[ClayMask]

That's great news!  Thanks, Nutella.

Joria, it looks like Carl added Deathflower to the gardening guide.  Seems like it is a real plant in The Sims 4, but now that the grafting bug is fixed, that concern of yours is gone.

[Joria]

Whoo hoo!!!  And just in time.  I was about to ditch that game and start over.  Thanks so much for the info.  I will happily graft away, AND send my space cadet back to the rocket ship.  I finally gave my gardener a job in space.