ForumTouchy Subjects ► What Type of Diet Do Plants Use
Yes, I am being serious, and quite possibly dumb.

But what type of diet do plants eat? I need some serious help.
  
One, this question is dumb. Two, why is this in Touchy Subjects? Three, plants don't have a diet. Ever heard of photosynthesis? Plants need nutrients to do that and survive. Some include carbon, hydrogen, nitrogen, oxygen, phosphorus, and potassium.
  
I don't understand this question. Keto, obviously.
  
Is there a word for what plants eat that fits with titles like carnivore, herbivore, etc?
  
Very interesting questions. Not dumb at all. I like it. There are no stupid questions in biology.

Okay, so... if you're talking about eating as in like ingesting* another organism then the only plants that could fit would be carnivorous plants. They actually do 'ingest' insects by trapping them and dissolving them and absorbing the nutrients through cells in the lining of where the insect was 'eaten'. It's not just insects either, there are some plants that will consume small fish and crustaceans and plankton. But really plants get their main source of energy, glucose (like us and everything else), from photosynthesis and everything else they need, they get by absorbing it from the soil.

There are some plants that you can make a case for them eating other plants, you know to fit the idea of an herbivorous plant, but those are more along the lines of a parasitic infection/invasion of its stalk/trunk/limbs/etc. Like mistletoe. A lot of you have probably seen it before but might not know it. Here's some young mistletoe growing directly on a tree. You can see it better in this one. So this is really still the same as using its roots to absorb nutrients and not 'eating'.

*note that ingest refers specifically to taking something into a stomach, which, plants don’t have

But also here’s a plant trapping a fly. These cute little guys are called Sundews.

So that’s the difference between the two things. We’ve got one plant that’s catching and dissolving and absorbing the nutrients from an animal and another plant that’s invaded the body of another plant.

Also carnivorous plant diets typically consist of typically whatever small insects are available in the area; usually things like flies, mosquitoes, gnats. Sometimes bigger ones too. Carnivorous plants are pretty indiscriminate and aren’t always limited to insects. As long as it can get caught in their traps then they’ll eat it.

It’s worth noting that carnivorous plants also get a lot of their nutrients from the soil.

And if you’re wondering what kind of nutritional needs, it’s really about what you’ll see any organism needing; a lot the same stuff as us and in similar amounts too. The trace nutrients we need like iron, copper, chromium, manganese and molybdenum, etc; those are trace needs for plants too. We differ in our amounts for other things though; plants don’t need much sodium at all or chloride. Mainly they need carbon, water, nitrogen, potassium. A little bit of sulfur and calcium and potassium but not as much as carbon, water, nitrogen. But except for carnivorous plants who get it from insects and parasitic plants who get it from other plants, plants get all of their nutrients from the soil.

I really like plants. It’s kinda funny. Plants get what they need from the soil, animals eat the plants, other animals eat those animals, those animals and plants die and become part of the soil. “All go to one place. All are from the dust and to the dust all return.” Ecc 3:20
  
As noted, none of the '-vorous' terms are appropriate because plants are not (with some also-noted exceptions) ingesting their food. The technical adjective for plants' diet is photoautotrophic.

SbF5's answer is the best answer, though
  
Forum > Touchy Subjects > What Type of Diet Do Plants Use