Ask Mr. Smarty Plants

East Palatka holly tree is a hybrid  of Ilex opaca (American holly) and Ilex cassine (Dahoon) that was discovered in Florida in 1927, and is also known as Ilex x attenuata ‘East Palatka’. From this first link, we learn that the tree prefers well drained soil, will grow in sun and part shade, and has moderate salt/chloride tolerance.

Given the short life span of your plants, Mr. Smarty Plants is suspecting transplant shock, perhaps because the roots of the plants were just too wet. I’m including links to three sites that do a good job of explaining this problem, and give tips for preventing it.

North Carolina State University

Northscaping.com

Gardeningknowhow.com

I found two other links that should allay your concerns about the chlorine in the pool water. One is from a previously answered question, and the other is from Cooperative Extension in Harnett County in North Carolina.

To look for other plants that might work in your situation, go to the Recommended Species List on our Native Plant Database Page. Clicking on Central Florida will bring up a list of 239 commercially available native species suitable for planned landscapes in Florida. That’s too many plants for now, so go to the “Narrow Your Search” box and make the following selections: select Florida under State, shrub under Habit, and Perennial under Lifespan. Select part shade under Light Requirement, and Moist under Soil moisture. Click on the Narrow Your Search Button and your list shrinks to 54. Clicking on the scientific name of each plant will bring up its NPIN page that contains a description of the plant, its growth requirements, and photos. Look for plants whose growth requirements meet your growing conditions.