Bromeliad splotches

Question: I have 20 pots of bromeliads that contain with pups over 3.5 doz plants which have evolved over several decades.  About a third are vertically striped (neoregelia?) of which half  have the splotches showing in attached pics.  Is this a fungus which could be controlled or should be tossed, or is it genetic so no hope to irridicate?  Thanks.

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied March 17, 2023, 11:48 AM EDT
response: We're not certain what the cause of damage is, but suspect growing conditions instead of issues of pest or disease outbreaks. Have any chilly drafts hit the plants, and does the growing area get good air circulation? (Are the plants misted, or only watered in the "tank"/cup of the plant? Misting foliage might allow for easier infection by pathogens until the leaf surface dries.) Has any spray (pesticide or otherwise) been used on or near the plants before this damage appeared? Were any updates to grow lights made, where the light intensity output has increased? (Or are the plants in a greenhouse?)  We don't have extensive bromeliad experience as they are not as commonly grown here, so we may need to reach out to other Extension resources or experienced tropical plant experts outside of Maryland to see if they recognize the cause. (In that case, we can also share with them the information you provide us regarding the questions above, and hope to have some feedback during next week.)  Miri

responder: The Question Asker Replied March 17, 2023, 12:31 PM EDT
response: Really appreciate your effort.  I was hoping it is a common issue for the genus that someone would recognize.  I should have mentioned that it is not on every leaf of a plant (usually 20-33%), it is mainly visible on top side, and it is in the tissue not raised.  Let's eliminate some issues by responding to your questions.1. This variety is in one room facing east on shelves 12-18" from double pane windows, with reasonable space and no artificial light. 2. There is water in cup and I water the loose mix soil once or twice a week.  I mist irregulariy but never when there is sun (in morning).3. No pesticides or other sprays have been used.Hope this helps.On Fri, Mar 17, 2023 at 11:48 AM Ask Extension <<personal data hidden>> wrote:

responder: The Question Asker Replied March 17, 2023, 1:40 PM EDT
response: I forgot that there is also recent presence on this Vriesea Splendens.

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied March 17, 2023, 2:04 PM EDT
response: Thank you for the additional information and image. We'll see what we can find out via consultations and will get back to you as soon as we have feedback.  Window-only light from an eastern exposure is potentially insufficient for long-term health and vigor of the plants in general, even if not necessarily responsible for this issue.  A southern- or western-facing window usually receives more intense light, but even then might not be enough overall. Bromeliads like these prefer much more intense light (not full sun per se, but quite bright relative to typical indoor light levels). Supplementing their light with a grow light source might be useful going forward. Or, if you have the outdoor space, growing them outside in part shade in summer (from about late May through early October, potentially) can help them receive the light they prefer and "stockpile" carbohydrates to help carry them through the leaner times of winter indoors.  Have you observed any armored scale or thrips on any other plants in that area? Scale are perhaps the most common insect pest on bromeliads, though in our experience they tend not to cause damage this widespread. (Thrips might, as may certain types of mite.) The linked pages don't pertain exactly to the particular scale and thrips species that might be attacking tropical plants indoors, but still contain general information about each that might be useful for inspecting the plants. We don't see either pest in the photos, but they are small and might be easy to miss, especially if a mobile pest like thrips wasn't roaming around the damaged leaf portions at the time. (Scale adhere to the leaf and don't move.)  Have the plants been fertilized since prior to the symptoms manifesting? If so, is the fertilizer used one formulated for air plants (epiphytes like Tillandsia or orchids, often) or a general houseplant formulation? You've been growing the plants for so long that we presume no drastic changes in your care for them will be a factor, but we're trying to cover all the bases. When was the last time the potting mix was refreshed (at least on the symptomatic plants), in case old fertilizer "salt" residues have built up in the substrate? Is a household water softener used by any chance, where that water source is used to water the plants?  Miri

responder: The Question Asker Replied March 17, 2023, 4:26 PM EDT
response: The room has a wall of 4 windows together, each 32w x 70h, and the plant shelves are at the middle 2 with nothing including drapes obstructing light from the 2 at ends.   Therefore, they are getting more light than you probably assumed. I am familiar with those insects, and others, but there has been no sign of any in the 8 yrs of growing there.No water softener.  I draw water at least several days in advance to allow chemical evaporation and reaching room temp.  Fert is once a mo with half (or less) strength liquid rotating between organic and chemical.  I don't see any salts on pot or soil, but I don't repot, except bviously when the old plant dies back I start the pups in new mix which is combo of potting soil and bark.Thanks for your willingness to stick with this.On Fri, Mar 17, 2023 at 2:04 PM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied March 24, 2023, 10:21 AM EDT
response: Thank you for your patience as we've waiting to get additional feedback. Unfortunately the consultations we were trying to reach haven't come through for us yet, we think because there is a conference the people are attending and less accessible via email. Our in-house plant pathologist is still fairly certain these are abiotic symptoms (that is, not caused by pest or disease but instead by environmental conditions), but isn't sure what exact factors triggered the damage. Based on the leaf patterns he thinks maybe something happened while those particular leaves were still expanding, but we're not certain.  To answer your original question, we don't think it's likely the plants would need to be discarded and they will probably grow out of the damage gradually, in that forthcoming new leaves would emerge normally unless the environmental stressors repeated themselves.  Would you like us to try to reach out to someone in Extension down in Florida, perhaps? (Our thinking is that since lots of these types of tropicals are grown more widely there, both as landscaping plants and for shipping to nurseries in other states, that maybe they'll have more experience and recognize these symptoms.)  Miri

responder: The Question Asker Replied March 24, 2023, 11:10 AM EDT
response: Truly appreciate your extra effort.  Since this is not an urgent matter, it seems appropriate to wait for your orig contacts to respond.  If after a month there has been no response, then contacting Florida would be much appreciated.  Let's tickle for 5/1.  Thanks. On Fri, Mar 24, 2023 at 10:21 AM Ask Extension <<personal data hidden>> wrote:

responder: The Question Asker Replied March 24, 2023, 11:10 AM EDT
response: Truly appreciate your extra effort.  Since this is not an urgent matter, it seems appropriate to wait for your orig contacts to respond.  If after a month there has been no response, then contacting Florida would be much appreciated.  Let's tickle for 5/1.  Thanks. On Fri, Mar 24, 2023 at 10:21 AM Ask Extension <<personal data hidden>> wrote:

responder: Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied March 24, 2023, 11:17 AM EDT
response: Thank you for understanding! Feel free to reach back out around that time if you haven't heard from us in the meantime. We'll reply in this question thread if we receive any feedback in the meantime.  Miri