July - last edited July
If you have Spikeweed (and Hypnoshroom) in your Zen Garden boost them before trying the 10th level
I finally completed it but used up too many coins for Power Buttons (cold was the best to keep Zomboss frozen while a Gargantuar caused even more damage
Enjoy and good luck !
Try this helpful glitch if you do buy it.
If you have the necessary 250 seeds to unlock a plant purchased with seeds (seedium) then it may be possible to upgrade it to level 5 without buying more seeds.
Buy it, unlock it then leave the game without doing anything else then go straight back to it.
If you're lucky the plant is unlocked and the 250 seeds are still available to level it up to level 5.
This seems to work on all "seedium" plants, from my own experience it works half the time (i have 3 profiles) but you only get one attempt.
This is a longstanding glitch and EA may have fixed it so it no longer does it.