Plant care guide
Scale on Bromeliads: Spot the Insects, Spare the Leaf Scales
Updated · First published
Why does my Bromeliad have scale?
Raised, oval tan or brown bumps on bromeliad leaves, often near the leaf bases, along the leaf undersides or tucked into the overlapping leaf sheaths, are scale insects. Do not confuse them with the fine silvery scales that coat many bromeliad leaves naturally.
What to do first
Isolate the plant, confirm the bumps lift off, and scrape them away with a fingernail, toothpick or soft toothbrush, working into the leaf bases. Test any oil or soap labeled for houseplants on one leaf first, flush the central cup afterwards, and keep checking for weeks.
Bumps on a bromeliad can be alarming, but check what you are looking at before you scrub. Many bromeliads carry natural scales on their leaves, and those are part of the plant. Insect scale is a separate problem. Clemson Extension names scale and mealybugs as the most frequent insect pests of bromeliads, and UF/IFAS says that while bromeliads are fairly pest-free, scale and mealybugs can sometimes be a problem.
Natural leaf scales or scale insects?
Clemson notes that some bromeliads have silvery-gray scales covering the leaves. UW–Madison Extension describes Tillandsia leaves as densely covered with fuzzy scales that give their gray color, and some Vriesea as patterned with scales (UW–Madison: Bromeliads). Clemson describes some urn plants (Aechmea) with bands of silver scales. These are an even coating or a regular pattern, and they belong there.
Scale insects look different. Clemson HGIC’s houseplant pests factsheet describes them as small, immobile, legless bumps, 1.5–13 mm (1/16–1/2 in) across. University of Maryland Extension says they flake off with a fingernail, toothpick, cotton swab or soft toothbrush (UMD: Scale Insects on Indoor Plants).
Signs of insects:
- Separate, raised oval bumps, scattered or clustered, not part of a regular pattern.
- Sticky leaves. UMD calls honeydew the main sign of soft scale. It can grow black sooty mould.
- Yellow spotting or yellowing where they feed, which UMD lists among the symptoms.
Where they hide on a bromeliad
UMD lists bromeliads among the hosts of brown soft scale. It notes this species can hide underneath leaf sheaths and in crevices between emerging leaves, and feeds along veins and leaf undersides. On a rosette, that means the overlapping leaf bases that form the cup.
NC State Extension lists scale on the foliage and flowers of Aechmea fasciata and advises monitoring for scale and mealybugs. Check the flower spike and bracts too.
What to do
- Isolate the plant. UMD advises quarantining plants with scale.
- Scrape off the insects. Use a fingernail, toothpick or soft toothbrush. Gently part the outer leaves to reach the bases. Spiny-edged types such as Aechmea call for gloves.
- Remove badly infested outer leaves if they are heavily covered.
- Treat with care. We found no extension guidance on how bromeliads tolerate soap or oil. Clemson advises testing any insecticide on a small part of the plant before treating the whole plant, and lists insecticidal soap and oils for crawlers. Colorado State Extension rates spray oils as the most effective scale treatment (CSU: Managing Houseplant Pests). Use a product labeled for houseplants.
- Flush the cup afterwards. Clemson advises flushing the tank periodically with fresh water to prevent stagnation. Do it after treatment so product residue does not sit in the cup.
- Keep checking. Colorado State says treatment must cover a whole scale generation, two to four months. It adds that dead scales can stay attached and look alive.
UMD says heavily infested plants are best discarded. A bromeliad dies slowly after flowering anyway, according to UF/IFAS, and produces pups at the base. If the mother plant is badly infested, inspect the pups closely before keeping them.
Pets
The ASPCA lists blushing bromeliad (Neoregelia) as non-toxic to dogs and cats. Treatment products are another matter, so keep pets away until sprays dry.
Prevent a return
- Change the cup water. NC State advises replacing it monthly, because stagnant water can breed insect pests.
- Inspect new plants. UMD notes brown soft scale occurs worldwide and can arrive on any plant shipment.
- Avoid soggy mix. Clemson and UF/IFAS link most bromeliad problems to root rot from excess moisture; a healthy plant is easier to clean up.
For cup care, see watering a bromeliad’s central cup. Our scale insects guide covers scale biology, and cottony tufts point to mealybugs instead.
Related guides
Other bromeliad problems we cover: repotting. For an overview of every common bromeliad problem, see bromeliad problems and solutions.
References
- Clemson Cooperative Extension: Bromeliads
- UF/IFAS Extension EP337: Bromeliads at a Glance
- NC State Extension Gardener Plant Toolbox: Aechmea fasciata
- University of Maryland Extension: Scale Insects on Indoor Plants
- UW–Madison Extension: Bromeliads
- Clemson Cooperative Extension HGIC 2252: Common Houseplant Insects & Related Pests
- Colorado State University Extension: Managing Houseplant Pests
- ASPCA Animal Poison Control: Blushing Bromeliad
How this guide was put together: Clemson Cooperative Extension, UF/IFAS Extension, NC State Extension, University of Maryland Extension, UW–Madison Extension, Colorado State University Extension and ASPCA guidance.