Q.Tibouchina Fertilizer And Care
My outdoor Tibouchina (Princess Flower plant) bloomed the first year it was planted but since then has been loosing leaves (they turn yellow-orange and drop off). Could this be due to soil that is not acidic enough? If so, can I use acidifier for hydrangeas to change the ph? Or just lack of fertilization in general? Thank you.
Certified GKH Gardening Expert
You're right that they do need acidic soil, but don't overdo it. A pH of 7 or below is fine.
https://www.gardeningknowhow.com/ornamental/shrubs/princess-flower-bush/growing-princess-flower.htm Use the same fertilizer that's used for rhododendrons and azaleas. You may want to test your soil to make sure it's not too alkaline.
Another thought is that you may have overwatered it in the cool weather and waterlogged the roots. If that's the case, it should come back as the season changes. Make sure to keep the surrounding area clear of dead leaves, and examine the bush for any pests that may have taken up residence.