Browse resources Displaying 1 - 3 of 3 resources Photo by Lynn Ketchum. (Cropped from original) Rhododendrons and azaleas need a strong acidic soil The most effective way to correct an iron deficiency for these plants is to acidify the soil. Jun 4, 2024 | News story Credit: Jennifer Alexander (Cropped from original) General care for hydrangeas Look to this hydrangea how-to for advice on soil, water, pruning and more. Learn a simple pH trick that will turn blooms from pink to blue. Kristin VanHoose | Jun 2018 | Article Peer reviewed (Gray level) Photo: Tom Brandt (Cropped from original) Can Kincaid's Lupine improve my soil? Q: I'm an urban rental dweller in West Portland, and the soil in my yard appears to be of very poor quality and I can't afford to purchase fertilizer to improve it. My yeard is full of dandelions and weeds currently. After...A: View answer | View all featured questions