Tree failures along State Road A1A tied to saltwater intrusion; CRA to replace select palms and pilot alternative plantings

CRA staff and consultants told the board on April 2 that clusters of recently planted Montgomery palms along State Road A1A are failing because of standing wet, saline soil in the small sidewalk planting pits.

Jonathan Hague of Kimley‑Horn presented project history and planting layout along the A1A streetscape, noting that constrained sidewalk widths required trees to be planted in 36‑inch tree‑grate pits to preserve ADA passing clearances. He described extreme wind and flood events since installation (late 2023–2024), then introduced consulting arborist Lisa Hammer, who detailed field and laboratory findings.

Hammer said soil cores and a water sample from several failed pits showed very high sodium, chloride and soluble salt levels consistent with seawater. In one sampled pit inspectors found standing water and an old irrigation sleeve that retained water;…