Question
I live in Houston.  My wife has purchased zinnia's in 6inch pots. She wants to plant them in a spot where they will get full sun from about 11am to 1pm.  The rest of the time is in the shade.  Her questions: Will they continue to bloom with that much sun?  How often should she water them?  How often should she fertize with Miracle-Gro?
She also has attempted planting verbena in the ground and in pots in full sun.  They bloom well in April/May, but seem to stop blooming and even die after that. Is Houston summer too hot for verbena?  Or is she over/under watering or fertilizing.  She would water them every morning and fertilize once every two weeks.  We also have a problem with snails.

Answer
Verbena is from south america and should like your hot sun. It is very draught tolorant and generally do better with infrequent but deep watering rather than daily water. Try watering 1-2 times per week max. Miracle grow every 14 days is fine.

Zinnia loves hot afternoon sun even in Texas. 11 am to 1 pm is just fine your your zone. fertilize with miracle grow every 14 days. They do require a lot  more water than verbena, but when you water, water deeply and avoid splashing the foliage or you get mildew and very unattractive plants. instead use soaker hoses which are covered with mulch or direct the watering can to the base of the plants.

Snails can be eradicated by using snail bait available at garden stores. they can completely defoliate plants in one night and can be a serious pest. Watering in the morning instead of the late evening can also help keeping them at bay.