Flourishing Orchids Produce “Happy Sap”

I’m so used to sticky, sap-like substances on my plants indicating the presence of pests, especially scale, that it never occurred to me that honeydew on my orchid leaves was anything other than a bad sign. But as usual, orchids have to be orchids. After years of wiping clear, sticky resin off of my orchid leaves and treating them for scale, I recently came across an article referring to orchid honeydew as “happy sap.” 

As it turns out, sometimes the presence of sap or nectar means an orchid is living its best life. Other times, it means the orchid is overwatered and is trying to shed excess moisture. And sometimes, the sticky resin is caused by scale, mealybugs, or aphids. To figure out which accounts for the honeydew production on any particular orchid requires some up-close and personal time with the plant.

Droplet of happy sap on a phalaenopsis spike

Where on the sap is located and where the orchid is in its growth cycle are the two best clues about what the honeydew means. If your orchid is actively producing new leaves, pseudobulbs, or flower spikes, and if the sap is located on or around any of those actively growing parts, then that’s a good sign. Spikes and blooms require extra hydration and nutrition, so orchids pull nutrients into those areas. Honeydew formation along blooms, stems, and spikes means they’re getting what they need and then some.

Even “happy” sap can cause problems if there’s so much of it that it drips down onto leaves below. Like maple syrup or honey, orchid sap is thick and sticky, and when it sits on a leaf (or any part of the plant) for too long, it can end up killing cell tissue. That’s an open invitation to bacteria, fungi, viruses, and other stuff we don’t want to mess with. Insects, particularly ants, also are drawn to the sugar-rich honeydew. Excessive sap should be carefully wiped off with a soft cloth or Q-tip moistened with water. 

Blistering from edema

Droplets of sap on the underside of the leaves, kind of like rain build up on the underside of an awning, often indicates overwatering. The guttation, or releasing of water from the underside of the leaf, is the plant’s way of getting rid of excess water. This is especially common in winter months if people don’t reduce watering. Edema, blisters that form on the top of the leaf, also indicate that the leaves can’t transpire enough water to keep up with the amount of water the roots are taking up. Wipe off these droplets. As orchid guru @Orchideria notes, the undersides of phalaenopsis leaves are particularly sensitive and should be treated with extreme care. 

This isn’t “happy” sap. The orchid isn’t blooming or actively growing, and there’s what looks like scale near the bottom right edge of the leaf

If the orchid isn’t in spike or bloom, and if it’s not being overwatered, then the sticky resin might be a bad sign. Instead of being sap, this resin is actually the waste of pests that are eating and excreting plant material. If that’s the case, you want to treat the pests and wipe down the leaves. 

Ah, orchids. Always being a little extra. But they’re extraordinary, which is why I love them. Forgive me for being such a sap. (Groan).