|I believe I overwatered my Philodendrons and now have root rot as the leaves are tuning black and falling off. Is there any way to save them?|
|This is a difficult question. Sometimes the plant can be saved but it is a sort of drastic procedure, along the lines of kill it or cure it. Start by removing the blackened foliage and stems, cutting them off with a sharp knife or razor blade and dipping the blade in bleach/water solution in between cuts. (Nine parts water, one part ordinary chlorine bleach.) Next wash the soil off the roots, cut away any blackened or rotted roots, then dip the remaining rootball in a solution of water and household bleach and finally replant into clean fresh soillless potting mix. Use a mix formulated for container plants. Make sure your container has functioning drainage holes in the bottom. Use a new container or scrub the old one thoroughly and dip it in bleach water and then allow to air dry. Then cut back the top growth proportionately to compensate for the lost roots -- unless you already removed much of it.
From then on, water only when the top of the soil is dry. Use your finger to dig into the soil a bit and see if you need to water or not. If the soil is still damp, do not water yet. When you do water, water thoroughly and allow the excess to drain out, then promptly empty the saucer of the excess water.
Also, try to keep the plants in overall good health by providing ample light, good air circulation, and fertilizing sparingly. Use a quarter the label rate of a water soluble fertilizer for foliage plants with an analysis of 10-10-10 plus minors or similar proportions and fertilize only when the plant is actively growing from spring through fall. In winter, keep the plant out of both hot and cold drafts, and provide an average room temperature of 60 to 70 degrees. I hope this helps!