Put this one at the top of your list...Brookgreen Gardens located a fairly short drive south of Myrtle Beach on Rt. 17. And be certain to walk the old sections of Charleston to peek into the hidden gardens. If a gate is open you are welcome to enter the garden. Another must see is Middleton Plantation.

Thank you, Nandina! I'll definitely put those on my list.

There is a nice size Botanical garden at the Riverbanks zoo in Columbia. Worth the trip and the bonus of the zoo makes it a fun time as well.

Here is a link that might be useful: Riverbanks Zoo

Just north of Charleston:
Cypress Gardens
Moncks Corner, SC

Just South of Charleston
Charleston Tea Plantation's
AmericaÂs Only Tea Garden
http://www.bigelowtea.com/act/

Here is a link that might be useful: cypress gardens

Greenville, SC.... Falls Park

I have pics from my visit if you would like to see. The waterfalls are beautiful.

http://www.fallspark.com/visitor.asp

Here is a link that might be useful: Personal pics of Falls Park

Thank you so much for all of the great suggestions! I'm very excited to see a lush, green garden in April. I generally have to wait until mid-June in Colorado before I get to see more than a hint of green!

Also in Charleston, Middleton Plantation and Magnolia Gardens. (Or is it middleton gardens and magnolia plantation?)

Anyway, they both have web sites that would give you an idea of what you would see.

I second Brookgreen Gardens at Myrtle Beach. Fantastic! Watch the slide show on this site. You could spend a couple of days there and not see everything. In April, the azaleas should be putting on a very nice show.

http://www.brookgreen.org/

I would plan for about 45 mins. to an hour from Myrtle Beach to Brookgreen Gardens. It actually sits between Myrtle Beach And Georgetown on US HWY 17 heading toward Charleston. Brookgreen has many gardens, but it also has a side with animal exhibits as well. The gardens are also the location of many sculpture exhibits.

I would plan for about 2 1/2 to 3 hrs. to get to riverbanks zoo from Myrtle Beach. The gardens are located across the river from the zoo, but they are connected by a bridge. You can park at the entrance to the botanical gardens, however, if you park on the zoo side you may want to take the tram (glorified golf cart type thingy) to the garden. It sits on top of a BIG hill.

Give yourself about 2 1/2 to 3 hrs to get to Charleston from Myrtle Beach. Others have already mentioned the highlights.

Also, I am not familiar with the Wilmington, NC area, however, I believe there are some gardens there as well and Wilmington is about 1 1/2 to 2 hrs from Myrtle Beach.

Thank you, thank you, thank you! I'm so excited. No azaleas around here -- it'll be great to see them put on a show in April.