Knowing what types of vegetables to plant and what time of year to plant them has a major impact on how successful you will be. Depending on where you garden this can vary greatly. You can find this information in several places but your state agricultural Universities are a good place to start. In Georgia you can follow this link to a vegetable planting chart put out by University of Georgia. Click Here Other states have similar charts as well. I divide my planting into two groups, the crops that do well in cooler weather and the crops that do well in warmer weather. In my area that means we have two short growing seasons that are cool ( Spring and Fall ) and one longer hot season that lasts from May until October. Some of the same crops can be planted in both spring and fall here and you can plant a succession of crops (multiples of the same crop) in our long summers.
Within each of these two groups I try to select the varieties that will grow the best for me. You can do this by first reading about the variety that you want to plant in seed catalogs and online. Ask other gardeners that have gardened in your area for advice. Some times you just need to try different things to see how they turn out. Trying new varieties is what my wife Judy is famous for but I have to intervene sometimes because she gets carried away. She tells me that I do the same old varieties all the time. My point is try something new but leave room for the tried and true varieties also.
One factor I look for in selecting varieties is to find out how long it will take to mature. This is called Days to Maturity in the seed catalogs. I know that in the spring and the fall we only have a short time in between our cold winters and hot summers (usually about 2 months in my area). I also have to know things like when is the average last frost of the spring is and the average first frost of the fall. Some varieties will tolerate a frost and some will not. I farm just south of Atlanta Ga. ( we are Zone 7b ). Our average last frost is Mid April and the average first frost is late October. I start off the gardening year with cool weather plants like Broccoli, Cabbage, Kale and Lettuce in Early March from plants not seed. These cool weather plants can get killed if we have a hard freeze so I have a row cover for protection ready just in case I need it. I also select varieties that are quick to mature ( 50 to 60 Days from planting ) because I only have about two months until hot weather comes in mid May.
The warm weather plants like Tomatoes, Peppers, Green beans, Okra,and Squash will not start growing until we have warm soil. That usually comes for me in mid April. Do I try to cheat that a little bit if I think we are going to have a early spring? Sure I do but I don’t plant everything early and get completely wiped out by a late freeze. I also plant more of my warm weather crops in mid summer but again I count how many days of warm weather I have left and match that to the days to maturity that way I know if that crop has time to finish before the first frost.
In the fall I can grow my cool weather vegetables again but I have to start the in the late summer when it is still hot in order for them to finish in cooler months of October and November. This can be a challenge sometimes but if I wait until it is cooler in October they will not have time to mature correctly.
So you can see knowing what to plant when is very dependant on where you live and what your climate is like. It may take a little looking but you should be able to find how to schedule your planting from others in your area. After all people have been growing gardens for a long time.