Answer: Planting distances depend on the mature size of the plant. For example, if the mature size is two feet wide, you would plant them two feet apart in order for them to just about touch at maturity. If planting two different types of plant next to each other, for example one growing to four feet and one growing to six feet wide, then you would plant them five feet apart.
Fertilizing depends on the fertility of the soil and on what you are trying to grow. In most cases a well prepared soil with ample organic matter such as compost or well rotted manure added would mean that an application of all purpose granular fertilizer such as 10-10-10 applied in spring according to the label instructions would be sufficient. It is actually no better to overfertilize than it is to underfertilize.
Another consideration is soil pH, and this you can only find out by running basic soil tests. Usually the tests will also tell you about the fertility, so it is worth the trouble to do them. Your county extension should be able to help you with the tests and interpreting the results.
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