I've fine a funny hack, try it and you'll LOL!
1/Open PvZ and Cheat Engine.
2/Plant a Wall-nut.
3/Type 3 to the value bar then click first scan.
4/Plant a Tall-nut at the same place of Wall-nut (after you dig the Wall-nut).
5/Type 23 to the value bar then click next scan.
6/Do step 2 again (after you dig the Tall-nut)
7/Change value 3 to 35.
8/Plant a Spikeweed at the same place you plant Wall-nut.
9/Change value 35 to 4.