It’s me, brown thumb, again

Question: Bought me a hydrangea from the market. 2 days later- it’s like a nuclear gas attacked it. Thoughts?

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 April 14, 2023, 5:06 PM EDT
response: If this occurred after the plant was put outside, then there are a few possibilities. If it happened inside first, then maybe a watering issue, mentioned below, was the culprit.  Hydrangeas put out for sale (often in a greenhouse at that point) for the Easter-centric and early spring season tend to be more tender varieties that are considered "florist" types. That is, varieties not reliant on hardiness, compared to those sold as regular landscaping shrubs, because their main purpose is to be forced into early bloom for colorful seasonal décor. It can be a bonus when these florist types are planted out in the yard and survive, but it's not a trait they are bred for, so sometimes they survive our winters but don't flower reliably because the flower buds got too cold. Since florist hydrangeas were forced into early leaf growth and flowering by being in a greenhouse at the nursery, they are not accustomed to outdoor conditions, both in the sense of overnight temperatures (when we were much cooler not long ago, anyway) and in terms of direct sunlight. True, greenhouses let in lots of light, but even the glass or polycarbonate roof (more so if a shadecloth was used) cuts-down on some of the light transmission so it's actually more intense light that the plant receives once outside. Either cold damage or the shock of lots of sun could have caused the singed-looking leaves and quick-to-fade flowers.  Hydrangeas also can be over-watered or under-watered when in pots this size, merely because they dry out quickly but also a pot cover like the one in the photo traps moisture instead of allowing it to drain. (If you removed the pot cover when watering, as should be done, this is less likely.)  In either case, this is temporary damage and trimming away the burnt bits will improve the look of the plant. A disease isn't responsible, and the plant may yet recover well once it has enough time to produce new leaf buds. (Leaves adapt to the conditions present when they are forming, which means those exposed to more light like this will be better-equipped to handle it compared to those that expanded in the greenhouse.) You can try to plant it in the garden if you want to see if it returns for future years. In that case, pick a location with well-draining but not-too-dry soil that receives part shade once the trees leaf-out fully. Total shade is fine but will result in few flowers; full sun might be tolerated but can easily stress the plants and may fade the flowers prematurely in the future. A site near an insulating wall might give it the few extra degrees of cold protection in winter that would allow more flower buds to survive for the following year's bloom, assuming that's an issue due to its heritage as a florist plant.  Miri

responder: The Question Asker Replied April 15, 2023, 4:31 PM EDT
response: You all are wizards. Honestly I shouldn’t be able to email you. I should be required to hike through hills and forests, cross streams and fight wildlife to find you all isolated from our world living in mystical caves, filled with botanical and gardening knowledge and wizardry that commoners such as myself seek for a lifetime.    Thank you once again for such thorough and informative replies to my seemingly never ending inquiries, blunders, faux pas and blatant stupidity.    You’re all true living gems.    Justin

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 April 17, 2023, 8:05 AM EDT
response: Thank you for your entertaining response, and you're quite welcome.