You must get the "Catalyzed x3" award for 25 different plants. Check your progress in your Journal, under Player Awards, then Plant Awards.
These awards are earned by using the correct fertilizer at the right time on each plant. I might be wrong about this, but it seems like you don't necessarily have to get all of the Catalyzation awards on the same specimen. For example, I had Catalyzed x1 and x2 for the Blackberry and then when I used fertilizer the first time on a new bush, that gave me the Catalyzed x3 award. Since it happened to be the 25th, I got the achievement at this time. If anyone has any more information about this, leave a comment.
You do not need to let the plant grow to maturity to earn these awards, but doing so will count toward the Master Green Fingers achievement. The plant must only live long enough for you to apply fertilizer the requisite number of times.
Please note that it does no harm to apply fertilizer at the wrong time. Just be sure you also apply it at the right time. You'll be able to tell the difference by the sound it makes.
I'll list each plant and the color of fertilizer in parenthesis. I've grouped plants which need similar techniques together, and put the instructions under each list.
01. Bird of Paradise (Orange)
02. Bluebell (Blue)
03. Bullrush (Brown)
04. Buttercup (Yellow)
05. Carrot (Orange)
06. Chili (Red)
07. Corn (Yellow)
08. Daisy (Yellow)
09. Orchid (Green)
10. Poppy (Red)
11. Pumpkin (Orange)
12. Snapdragon (Purple)
13. Sunflower (Yellow)
14. Tulip (Purple)
15. Turnip (Purple)
16. Watercress (Green)
17. Water Lily (Purple)
- For these, just use three doses of fertilizer immediately after planting the seed.
18. Monkeynut Tree (Brown)
- Even easier, use just one dose right after planting it.
Unfortunately, the rest of the plant species require more attention. You must watch them grow carefully and apply fertilizer at specific times. Your selection is pretty limited because you cannot get this award for anything considered a weed (Poison Ivy, Thistle, Toadstool, and Venus Pinata Trap). Be sure to water all plants so they do not die before reaching the required point in their development. The One Pour Wonder, bought from Ivor after level 24, is a great thing to have. There are nine more plants and you need to do seven of them. I think these are the easiest:
19. Gem Tree (Blue)
- Arguably the next easiest thing to grow (purchase seeds from Ivor), because it also requires only one dose. After a time, the tree gets these fairly large bulb shaped things which explode and drop a bunch of leaves. After this happens the SECOND time, apply one dose of fertilizer and you should get the award.
20. Fir Tree (Brown)
- This one only requires 2 doses of fertilizer. Apply one after the tree shakes its leaves off for the first time (Basically, you should see a bunch of green particles falling down all around the tree, much like the explosion from the Gem tree). Then the second dose comes after it shakes its leaves off again, but it's not the second time. Sorry I didn't keep count, but you'll know it's the right time when a couple of the tree's distinctive 'leaves' are sticking out of the top, but before there are any branches.
21. Banana Tree (Yellow)
- Basically, watch for the green bulb ON TOP of the trunk. When it bursts open, pour fertilizer. It seems to only require two doses, although the wiki says three. I didn't get an actual leaves-falling animation the first time, for some reason.
22. Hazel Tree (Brown)
- Use the first dose immediately, then wait till it shakes its leaves off THE TOP BRANCHES twice to apply the second dose.
23. Gooseberry Bush (Green)
- Apply one dose immediately, then wait until the first time it shakes its leaves off to apply the second dose. After the third time it shakes its leaves off, apply the third dose.
24. Apple Tree (Red)
- Apply one dose immediately. After a few seconds of growing it'll have one side branch, and you'll see leaves fall off it, but this is not your cue. Wait until leaves fall from the top of the tree to apply a second dose. Once it happens again (I repeat, off the top of the tree, not the branch), use the third dose.
25. Blackberry Bush (Purple)
- Watch for the buds to appear, and apply fertilizer then. Don't wait for them to burst open like the other plants. Like I noted above, I got this after the first time, however, the wiki claims you need to do it after the second and fourth buds appear. I don't even think I saw a fourth set of buds, so who knows.
I believe this achievement took me a couple of hours (including writing this) and about 5000 gold coins, or thereabouts. Of course, selling the trees made up for the costs and then some. Big thanks to the Pinata Island wiki (
http://pinataisland.info), which helped me get these awards and many others. I compiled the information here using their pages after verifying (or in some cases apparently, correcting) it for myself.