New 60 concrete box needs sealant to prevent alkaline leeching
Dear experienced hydrangea enthusiasts please share your advice.I have been waiting for years to have hydrangeas in abundance again.
We just had our patio and outdoor living room slabs poured.
We added a 60 foot long x 30 inch high and 24 inch deep planter constructed in front of a wall of huge boulders.
The base of the planter is soil and our underground utilities run under the soil.I have been successful growing mopheads in 20 " diameter pots for the last five years and controlling bloom and color. The lime in the new concrete
face wall will completely alter the ph of the soil.
What could I use to seal the interior surface of the planter before it is planted? Would a styrofoam insulation
spacer be enough? Once the planter box is filled with soil there will be no way to empty it. I can only amend it from the surface.I want to keep my hydrangeas blue.
Thanks for your suggestions.