Epic quest wild west wipeout

It is possible. 

I have done it with level 1 plants (albeit after 3.5 hours possibly more than 35 attempts)

You can pick up some tips from the link below (not done by me but a respectable player I came across) who is also using all level 1 plants.

https://www.youtube.com/watch?v=N1srmPPHOZ8

I think the trick is to take the items off the conveyor as soon as it appear so to maximizing the placement of Hypno-shroom for the defense.  I have also found out level 1 Hypno-shroom works better than level 10 as it turns the zombie instantly. 

EDIT: adding missing part of my post.

If you take too much time then Gargantuars start arriving on the lawn and you are certainly doomed.

Hurray.  I just received Hypno-shroom and Spikeweed in my Zen Garden (second attempt to do this) so I will have a chance to try boosting both before trying the 10th stage of the WW Epic Quest.

*shakes fists angrily at the chickens*

I did this second try by fluke the first time I completed this stage without boosts. Last night (maybe I was a bit tired) those darn chickens just sneaks right through my defenses! After an hour I had to stop.

Also wasted my Zen Garden hypno boost. 😢

But you did garner the 100 GEMs ??  Hurray if you did and pat yourself on the back for getting through a torutrous level/challenge.

👍 got it... was frustrating as all heck, but must lucked out after much frustration :D

Awrighta !

Zomboss rams through line and destroys my defences and chicken zombies, but leaves chickens alive, who can run freely to the house. How should I counter that if I even have not enough time to click on emergency buttons?