Producing gems in this game is possible through a few ways:
1 - Logging in daily to get One random gem
2 - Completing certain 'challenges' (I assumed it meant achievements, but only 50% of achievements ever gave me anything, no clue what challenges it means)
3 - Squashing fruits

This method of very quickly producing a lot of gems will be exploiting the squashing of fruits.
To do this, I recommend downloading this plant on the game's Workshop, I will explain why later:

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=3261675249

Second, I highly recommend downloading some form of auto-clicker. While not necessary, this method will assume you are going to be pressing the left mouse button thousands of times. To save yourself the inevitable aches, get an auto clicker



With those two tasks out of the way, let's move on to the method itself.

In order to produce the mass amount of gems, you will want to squish the largest amount of fruits you possibly can. The plant example I have linked earlier can achieve this relatively easily. I'll go over my basic routine for generating gems, as well as some tips in case your machine encounters issues

Step 0: (Optional) Show mercy to your PC
Turn your graphics WAYYYYYYY down. That means going to the main menu, turning off shadows, foliage/grass, and anything else which might get in the way. This makes the game looks worse, but will extend the amount of time you will be able to use this method, as well as making it much easier on your computer.

Step 1: Spawn your plant
Load in the plant I recommended you subscribe to earlier. It should be shown on the far right of your screen. This 'HELL_TREE' is essentially hundreds of apples clustered around a very thin branch, made bright green for convenience. Its leaves are incredibly small so as to not get in the way of this farming method, and it is aesthetically repulsive because I think that's funny.

Step 2: Harvest some apples
The next thing you should do is click the green section of the plant, this will cause apples to fall and hit the floor. Click these apples again a couple more times to 'squash' them (this should earn you an achievement too) and there is a small chance that this method will spawn a gem.
I do not know the specific ratio of which fruits spawn gems, and which do not, but in my experience it *feels* like 1/5, though could be higher/lower.
I usually begin by snapping the stem, then clicking the severed green part.
The apples should fly off of the tree, then scatter around the area. Example of this in work

https://youtu.be/szuNKXZZTls

This is why I recommend you download an autoclicker, simply activate it while hovering your cursor over the apples and collect the gems as they spawn. This is not a fast method, expect to sit around for a while in order to generate the needed gems, but using an autoclicker does alleviate some of the burden.

Example of all the apples you can spawn from this one tree

Gems which spawn after squashing them all (missing all the ones I accidentally picked up)

I would recommend doing this until one of two things happens, either you harvest and squash all the apples on the HELL_TREE, in which case, spawn another and start from the top.
Or, your PC begins to slow down due to the high amount of physics objects, in which case, I'd recommend squashing all the apples on the floor or spawning a new one.
There is little reason to wait when creating a new tree is as simple as clicking the icon on the right, and no penalty for doing so.

Step 3: Open up your gems
On the bottom left of the screen, there should be a gem counter, this counter DOES NOT MAX OUT even though the counter might say 9+ should you go over nine gems. This means that if you spend, say, thirty minutes using this method and catch over 50 gems, you can open them all without issue.
For the fastest method of opening gems, simply click the gem icon in the bottom left and spam the space bar. Don't bother reading the descriptions, they're literally worthless.

And, that's about it.

That should work for you. This method allowed me to collect pretty much all the gems I needed, much faster than the pathetic 1 per day method I was using prior.

As for the validity of this method over going 'legit', I would argue that seeing the steam page for this game mentioned implementing a 'store' at some point (I am assuming it doesn't specifically mean micro-transactions buuuut... I dunno...) I think this method is a fine way of quickly generating gems in an otherwise fine game.
The alternative methods of achieving gems are insanely limiting and tiring, and I am sure there are many out there who just want to see the pretty plants they are able to make.

If, in the future, this method does not work either due to patching or whatever, then do let me know.



On top of this, anyone with any information on how to get the other achievements (specifically the luring of deers, and any method for obtaining the 'secret space' one) is welcome to comment as well.

If you liked this guide, know that I did not do it for you.