killing my petunias

Asked July 6, 2016, 9:38 PM EDT

I made a big mistake with my lovely petunias (potted)...in the morning when i watered i added some sprinkles of pascalite clay to the pot...having read it was good for plants...4 hours later every single bloom has gone...the rest of the plant is still alive and green...what should i do to have more flowers again...is it hopeless?

Tuolumne County California potted plants petunias horticulture flowers: annuals and herbaceous perennials

1 Response

Pascalite clay can contain silicon, iron, calcium, magnesium, titanium, sodium, chromium, copper, manganese, barium, cobalt, boron, potassium, vanadium, nickel, cadmium, gallium, strontium, phosphorus, and zirconium. I expect you provided excessive minerals and shut down chemical transporters in the plant designed to gather nutrients from the soil. If the rest of the plant is healthy, you may want to consider repotting without the added clay. Several places recommend potted petunias be put into a soilless mix. You could then deadhead your petunias - a must if you want continual flowering and water with a liquid balanced fertilizer that has a high phosphorous content, such as 30/30/30 (the middle 30 is the Phosophorous number here) or even a 10/30/10; bone meal is also a good source of phosphorous. Petunias like high sun areas so keep them in a sunny spot. They are fairly drought tolerant - you should water weekly with a dilute liquid fertilizer and allow the soil to pretty much dry between waterings - although they do like it moist - it should be well drained.