WYNNEWOOD, Pa. (WPVI) -- It was a huge milestone today for the Pennsylvania Horticultural Society.
They are halfway into their Plant One Million campaign.
Tuesday they planted their 500 thousandth tree at the St. Charles Borromeo Seminary in Wynnewood.
It's in honor of Pope Francis' visit later this month.
The planting also coincides with the World Day of Prayer for the Care of Creation, which was established by Pope Francis.