Plants use their roots to get oxygen. Oxygen is dissolved in water, and there's also air pockets in their grow medium to provide a source of oxygen. When you water your plants too often, its roots are sitting in stagnant water which no longer has any oxygen left.
Which point(s) in the water cycle below best illustrate(s) water changing to a gas, and which term(s) could describe it? Is it.. 1; sublimation & evaporation. 2; evaporation only.
Water does not commonly form a gas, but rather a vapor which is slightly different (but really just the name of a gas that is normally a liquid). - There is latent heat in water so you can remove energy without changing the temperature of the water (only exactly at a phase change though).