Drive around and look at what works well in your particular neighborhood. The soil can vary so much. Anything from sand to woodland humus type. And of course, how much sun/shade on your property. Planting in April can be rough as a lot of things will not be able to establish good root systems before the summer heat hits. Plan what you want even though you may not be able to put some of the more delicate things in until Fall.

Ive been to St. Marys several times but havent seen too many nurseries so I cant help you there. Maybe the best thing to do would be to get a Jax phone book and look up a few nurseries and try them. I'd imagine Jacksonville would have some pretty nice nurseries.
Go with what you like. Do you like a tropical look? Palms, Cycads, Gingers and Bananas all do well in the SE Georgia heat and humidity, and look great for most if not all year round, (with the exception of maybe January and February). The Palms and Cycads wont miss a beat though.

i am here in camden county (st. mary's, kingsland)....there are very few good nurseries around here....the very best one i've found is the Ace Nursery on St. Simons' Island.....however, there is a nursery on U.S.17 in Yulee, Florida, before it crosses A1A,(sorry can't recall the name of it) that has shrubs, trees, palms, and mulch-by-the-yard....

there is also a guy at the Pecan Park Flea Market that has a pretty good sized plant booth, and he has a 'nursery' of sorts on Pecan Park Rd....i bought some staghorn ferns from him last summer and they have done well, however his greenhouses have been standing for so long and inside them it's really overgrown that i am hesitant to buy too much from him for concern over pests and diseases.......

there is also a nursery on U.S. 17 going north right after is crosses GA. 25.....you have to go through Woodbine and cross the river.....sorry i don't remember the names of these nurseries except for the Ace on St. Simon's......my neighbor asked the people at the Ace nursery if she could get some of the plants she was interested in at our local Ace here in Kingsland.....they indicated that they were willing to send down anything that was purchased.......hope this is helpful.........s.

eileenie.....azaleas, loropetulam, lantana (which butterflies like), plumbago, camellias, gardenias, crape myrtles, wax myrtles, pitosporum, sago palms, hydrangeas, buddleia (butterfly bush), canna lillies, amaryllis, boxwoods, eleagnus, oleanders, and ligustrums all do well here......also, unfortunately, oaks, scrub oaks, laurel oaks, oaks for days, oaks grrrrrrrrrrr oaks, oaks, and more oaks, not pretty oaks, you know: fall leaves, beautiful colors, noooooo, just squirrel driven oak making machines.......s.

I asked about Jax nurseries once on the FL forum and this is the list I was given:

Gecko Gardens
Trad's
Ace Hardware on University
Phillips on St. Johns
Second Hand Rose

I got to Trad's and Gecko and both were excellent. This was about 3 years ago however. Good luck. a