The lone voice of horticultural reason
“Groundcovers have a tough time under pine trees because the soil is too acidic.”
No. Test the soil before making that assumption.
Only rarely will one find the pH of the soil under pine trees to be more acidic than surrounding soil. Pine needles don’t add all that much acidity. If the soil around your yard tests at 6.5, the soil under the tree is probably 6.5. If you have alkaline soil, soil under a pine may drop to neutral, but it’s not going to be deathly acidic.
Groundcovers struggle under pine trees because the trees suck up all the moisture. We plant a nice shade groundcover under and around the tree, don’t water it heavily the first couple of seasons, then when it dies, we think the soil is too acidic.
The soil is fine. It’s just dry. The pine has a zillion secondary and tertiary roots lying only a few inches below the surface, and they’re using up all the moisture and nutrients.
Go ahead and plant your pachysandra, lamium, ajuga, asarum, and polemonium under pines (or spruce) but be sure to water them every week, more often in dry heat of summer. They’ll do fine.
The Renegade Gardener