how to make sure plants have essential nutrients

Question

Explain how I can make sure plants have essential plant nutrients in the correct amount.

Answer 1

You need to have your soil tested. A soil test will let you know what nutrients you have (and don't have) and what amount you have in the soil. From there, you can adjust your nutrients accordingly. Here is more information about soil tests:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm