Why Phalaenopsis Orchids Grow New Roots While Old Roots Dry Up and Die, and How to Fix It

If you grow Phalaenopsis orchids, you may have run into this: the new roots are sprouting away happily, and then you notice the old roots at the bottom are shriveled and dry, and you start to wonder- what on earth is going on?

Why do new roots grow while old roots wither? The most common reason is natural replacement; Phalaenopsis roots have a lifespan too. Once old roots reach a certain age, their ability to absorb nutrients declines, and the plant shifts its nutrients to the new roots, so the old roots naturally retire little by little. This situation is usually nothing to worry about - as long as the new roots are growing strong, it is normal for one or two old roots to wither.

But if too many old roots wither, you need to look for other causes. For example, watering may not be well controlled: either you water too little, and the old roots dry out and shrink from long-term lack of water; or you water too often, and the old roots rot while sitting in damp sphagnum moss, and once the rot reaches a certain point they dry out and turn black. It could also be unsuitable lighting: new roots like soft, diffused light, but old roots cannot stand strong light, so if the plant is placed somewhere with too much light, the old roots can easily be scorched, dehydrate and dry up.

Then there is the potting medium: sphagnum moss compacts over time, its air permeability gets worse, and the old roots, unable to breathe for a long time, gradually wither. Or you may fertilize too heavily - old roots are relatively fragile and easily burned by concentrated fertilizer, and eventually dry out and die.

So what should you do in this situation? First, you need to determine whether the old roots are simply aging normally or have a problem. Normally aging old roots are shriveled but not black, and come away with a gentle pull; if the old roots are black and soft and smell musty, then they have rotted and need to be dealt with right away.

When treating it, do not rush around in a panic. First take the Phalaenopsis out of the pot, gently remove the old sphagnum moss, and examine the roots carefully. Healthy new roots are white and tender with crystal tips. If the old roots are completely dried up, cut them off directly with sterilized scissors, being careful not to damage the new roots. If there are rotten roots, cut away the rotten parts completely until healthy tissue is exposed, then apply some carbendazim to the wounds and leave the plant in a ventilated spot for half a day so the wounds dry out thoroughly.

When repotting, remember to use fresh sphagnum moss; no matter how clean the old moss looks, do not use it again. Soak the moss in advance and squeeze out the water until it is semi-moist - too wet easily causes root rot, while too dry is bad for new root growth. Place the plant in, let the new roots spread out comfortably, and press lightly around it with your hands, without burying the new roots too deep.

After that, keep these points in mind for care: do not water too often, about once every ten days or so, just watering the sphagnum moss through each time; at ordinary times mist the surroundings to raise humidity, but do not pour water directly on the roots; choose a spot with plenty of diffused light, avoiding the strong light at noon; and do not fertilize for now - wait until the new roots are well established, then after a month or two apply a little light fertilizer.

Actually, when a Phalaenopsis grows new roots and its old roots wither, as long as there is no large-scale root rot, it is mostly a normal phenomenon. Remember not to fuss over it too much; give it the right environment, and Phalaenopsis is much tougher than we think!