Plants in toy powder dont really behave as if they are plants, so i ould like to suggest some improvements.

-When you burn plants they should relese all of the waater they have aborbed (well at least most of the water they have absorbed).

-Plants which have become a brownish color due to heat should turn back into a green color when given water.

-It would be cool and fascinating if plants could reproduce. maybe you could add a seed element.

-different types of plants. Plants which grow better underwater or can withstand lots of heat or some other sorts of alien type plants.

-plants should NOT burn on contact with photons. (unless there are extreme amounts of photons)

-plants should grow in distilled water. (although in lacks nutrients plants can still grow in it, just not as well)

-when you put a plant in water it shouldn't drink all of the water instantly, instead it should slowly absorb the water and grow upwards.

-if a plant drinks too much water instantly it should start to turn brown and then change into dust

I know you probally can't include all these things to the plants in powdertoy because your busy creating things like explosive, but it would be cool seeing powdertoy plants behaving with their enviroments realisticly.

You guys are right that it would break saves, but not all of these points will end up breaking saves. Besides plants would be alot more fun to interact with. (they just wont be growing matter which catches on fire)