What is 'bolting' in reference to growing plants?
This article will help you understand more about bolting in regards to plants: https://www.gardeningknowhow.com/edible/vegetables/vgen/what-is-bolting-what-it-means-when-a-plant-bolts.htm
What are "nematodes" and are they beneficial for fruit bearing plants, or are they some kind of amphibian?
Nematodes look like microscopic worms and exist in most soils. Some are very helpful to your garden because they attack pests, while others can be harmful to your garden because they attack your plants.
Here is an article that has more information on them:
https://www.gardeningknowhow.com/plant-problems/pests/insects/root-knot-nematode.htm
What is over seeding?
It is when you put seed down over an already established lawn.
I'm trying to find a definition of 'mounding habit' for plants. I have often seen this on the tags of perennials that I have bought.
A mounding habit means that the plant will grow in a short, rounded fashion, in the same shape as a "mound" of soil.
How can you tell if tree is alive?
These articles should help: https://www.gardeningknowhow.com/plant-problems/environmental/how-to-tell-if-a-plant-is-dead-and-how-to-recover-an-almost-dead-plant.htm
https://www.gardeningknowhow.com/ornamental/trees/tgen/what-does-a-dying-tree-look-like-signs-that-a-tree-is-dying.htm
What is the special or technical term for a garden which exclusively utilizes plant species indigenous to the area, and is left uncut/untended in order to foster a natural atmosphere?
This is generally referred to as a native or naturalistic garden.
Explain how I can make sure plants have essential plant nutrients in the correct amount.
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