How to make Glow in the Dark Flower Pots? We used Techno Glow Paint Collettsville, NC. Red Hydrangea. Potting soil must have really high pH. Houseplants Seeds Urban Farmer Brass Planters Stylish Gloss Pots 13.5 Inch Calla Lilies Planting Information Calla Lilies Care Guide Calla Rhizomes Plant Info Gardenistas Magic Soil Mix Recipe:, 50% potting soil, 25% Perlite and 25% Coco Chips (or Orchid Bark). All of these elements together allow your soil to drain well and provide nutrients as your plant