- Start with established pants since changing the soil can cause stress.
- If you’d like your flowers to be pink add Dolomitic lime (calcium magnesium carbonate) to the soil and test pH not going over 4.5 to 5.5.
- If you’d like blue flowers add aluminum sulfate.
Both additives can be purchased at any garden center. The aluminum sulfate is diluted in water usually 1 tablespoon per gallon of water.
After one season the colors will start changing. It takes a couple of years or more to get a deep blue or deep pink from the opposite color. Meanwhile, the flowers change into beautiful shades of purples, reds and pinks. You really can’t lose.
Search online for alternative ideas such as using vinegar or coffee to raise acidity. There are a lot of creative ideas using ingredients from home.