Mary, I grow veggies from September through May and take the summer off, just because of the brutal heat as you mentioned. I now tell my husband (when he comments that the weeds are getting waist high) that as the weather heats up the plants speed up and the gardener slows down. Then of course as the weather cools the plants slow down and the gardener speeds up again. So my garden is reasonably neat through the cool months, and a jungle in summer. I barely manage to keep the walkways passable, in my 10-minute weeding expeditions.
As far as pests, yes you surely must expect to battle every bug and fungus, but it's not that bad. I pretty much get by with three spray bottles, soapy water solution, 1/2tsp. dish soap to a quart of water, sprayed every few days for aphids, mites and white flies in one, baking soda and water (same recipe) against fungus in the second and BT in the third.
One thing I would tell you though - I've completely given up trying to grow any squash, cucumbers or melons here. There are just too many problems with them. I've even tried building a netting cage over my squash plants, and the powdery mildew then killed them before I got any harvest.
I get buckets of awesome tomatoes from November onwards until about May, using just the soapy water solution on a regular basis. Planting at the right time is key, though. You can plant tomatoes in September and if you're lucky they'll keep going and keep bearing right through spring. (you may have to cover them if the temps go below 40, but that doesn't happen very often) But if you lose them to cold weather or they stop bearing in the dead of winter, you can re-start them from cuttings or buy new transplants and plant again in late February. If you plant too late in the spring, the late blights get them. These are airborne bacterial blights that come along with the hot weather, and even the so-called "heat tolerant" tomatoes just up and die by June or so. One day your tomato plant looks good, and the next day it's standing there with all its leaves hanging straight down. Been there, done that the first summer we lived here.
You do have to keep your eye out for tomato hornworms, as they can defoliate a whole plant in a couple of days. They're so big though, you hardly can miss them. They are the size of your finger, green with diagonal white stripes across their body and a red "horn" on the back end to make them look fearsome. (they don't poke you though). I just pick these off by hand and feed them to the birds.
By the way, it's a great thing to have a bird feeder near your veggie plants as the birds will also help with bugs and caterpillar infestation on your plants. Watch those pesky cardinals, though. They like a red tomato once in a while.
