Are old Phalaenopsis (moth orchid) plants prone to pests and withering?

When you have kept a Phalaenopsis for a long time, do the old plants especially attract pests? Do they wither just like that? In fact, compared with new plants, old Phalaenopsis plants do indeed face more problems during care, and this is closely related to factors such as the plant's own condition and the growing environment.

"constitution" is changing. After three to five years of growing, the pseudobulbs at the roots of an old plant become rough, and the leaves may also have slight aging and damage; these places easily trap dirt and give pests an opening. The most common are scale insects, which cling to the underside of old leaves like a layer of small cotton fluff, and root mealybugs, which hide in the crevices of aged aerial roots and are impossible to spot without careful looking.

Why do old plants attract more pests? It is actually because their immunity is declining. The leaves of new plants are thick and glossy, with an intact waxy layer, making it hard for pests to bite through; the leaves of old plants become thinner, the waxy layer is not so sturdy, and on top of that the roots' absorption capacity weakens, with occasional root rot, turning them into a nutritious meal for pests. But there is no need to panic. If you find pests, isolate the plant immediately, dip a cotton swab in a little alcohol and wipe the leaves, bury a few granules of Huahuashen at the roots, and usually provide more ventilation and do not let the potting soil get too wet; this can basically keep them under control.

Now let's talk about the problem of withering. Old plants do run the risk of retirement, but they will not necessarily wither. A neighbor's Phalaenopsis had been grown for six years, and last summer half of it suddenly withered; it turned out that the old pseudobulbs had rotted. In fact, withering in old plants is mostly because they have flowered many times, consuming a lot of nutrients, and because the root system has aged, the ability to absorb water and nutrients declines. Once the environment is unsuitable, such as root rot from too much watering, or sunburned leaf tips from too strong light, it is easy for withering to start from the bottom.

But there are exceptions. My own purple Phalaenopsis has been grown for four years, and although the lower leaves have turned a bit yellow, it still blooms twice a year. The secret is not to fuss over it: when repotting, keep as many old roots as possible, and for regular fertilizing use diluted orchid-specific fertilizer, applying light fertilizer frequently so the old plant can slowly build up its strength. If you find yellow leaves at the bottom, do not pull them off forcefully; wait for them to fall off naturally to avoid wound infection.

Old Phalaenopsis plants need more careful attention. Do not let them sit in a stuffy, humid environment; do not give too much direct light; when watering, pour slowly along the edge of the pot and do not splash the leaf core. As long as these details are done well, old plants will not only be less prone to pests and withering, but may even produce new side shoots.