I have a couple of Oleanders in my garden that were doing great until recently.
Is this frost damage? We have only had one or two light frosts and the other oleanders in the neighborhood are doing just fine.
If it isn't frost damage, what could it be? And most importantly how do I remedy it?
I did have some aphids on them several months ago but I blasted them off with water and they haven't come back. I would appreciate any input, thanks!
If all you had were light frosts then I don't think that's it, unless these were ones that you just planted recently and hadn't had time to get established yet. I've never seen them show any signs of damage until you get more severe cold than that. We had an extreme cold snap last year where we had temps that got down to 19-20 at night for about a week, my oleanders were in pots up near the house since I hadn't found the right spot for them yet and they came through with no damage at all, but I think some of the oleanders in the freeway medians did get some damage from that weather. However in a normal winter where we get a number of frosty nights but temps don't get much below 25-30, they never show any damage.
I definitely don't think aphids could have done that, and I even had a pretty bad scale infestation on the ones at my old house and they didn't look anything like that--oleanders are pretty tough plants. The one thing that can get them unfortunately is Oleander Leaf Scorch, I know that disease exists in your area and your leaves look similar to pics I've seen of leaf damage from that disease. Unfortunately I don't think there's any way to cure it. This is a good reference from UC Davis that gives some info on it: http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7480.html They only talk about the distribution of it in CA, but I know from reading other things that it does occur in TX as well. The only thing that makes me question whether it's leaf scorch or not is the time of year that it showed up, generally it shows up more during warm weather rather than cold. If I were you, I would take a sample in to your local extension office and see what they say about it.
Thanks Ecrane3. I was hoping for your input. I'll definately take in the sample. Do you think they would recover if I cut back all the damage?
If it's leaf scorch, no they won't recover. You can temporarily make the plant look better by cutting back the affected parts, but there's no way to get rid of the bacteria that's causing the disease. Some oleanders will hang on longer than others so it's worth cutting them back from an aesthetic perspective, but it won't cure the disease. I would not cut them back until spring though--otherwise you could stimulate new growth which could get zapped by frost.
i am a bit north of you and my oleander has done well for the last 17 years --no matter how cold the winter was--and if i cut it to the ground it just came back good as new--so i agree that it doesn't seem like the cold did it!
Do you know if these are the "larger" more common 0leanders, or the dwarf varieties? They look like the "dwarf" varities to me. i.e. "Petite Salmon" or the dwarf pink variety. (Hard to tell exactly though, from the close up)
The dwarf varieties are NOT as cold tolerant as the larger, more common varieties you see growing as hedges , windbreaks, in street medians, etc. and tend to show frost damage pretty quickly.
Your photo looks like frost damage to me, as they look just like ones we did an informal hedge out of for a client, which were the Petite Salmon. They show the same type of foliage damage every year at this time when we get a light frost. They bounce right back in the spring, but we leave the damaged foliage on the plant anyway, then cut it off when the weather warms up.
I never knew the dwarf ones were less hardy. That would explain why the damage showed up now rather than during the warmer part of the year which is what I would have expected for the leaf scorch. If that is what's going on, that's also really good news, the plant can definitely come back and recover from that.
Thanks Jasper! To be honest I am not sure if they are dwarf varieties or not. Although they do have pink flowers. I had thought it was frost damage because they were ok before we started having the little frosts. - At least I didn't notice any damage until after then.
I guess I will try to cut it off in the spring and watch it for any signs of damage during the growing season.
Right now I think it can go either way because a couple months ago I did notice a couple of large grasshoppers on them. I shot them off with water, but it's possible they were carrying the bacteria.
I'll keep my fingers crossed and see what happens.
Thanks for all your input.
I don't think that grasshoppers transmit the leaf scorch bacterium...the main insects of concern are the glassy winged sharpshooter and several of their relatives. They're not as big and obvious as grasshoppers so I don't know if you would have noticed them on your plants or not. This is really not the time of year that the leaf scorch should be showing up for the first time, so now knowing that there are some oleanders that are less hardy than others and do show winter damage in mild climates, I suspect that's more likely. If you notice something similar developing during the warm part of the year, then you need to worry about the leaf scorch.
Would the sharpshooters have been on the plant for a while? I did a pretty thourough inspection of the plants shortly before the frosts and aside from some aphids on the new growth I didn't see anything.
I really don't know too much about them, but I think they're the sort of insect that flies around a lot and goes from plant to plant so unless you happened to catch it in the moment it was on the plant you probably wouldn't have seen it. They're not like aphids that take up residence on a plant and hang out there for long periods of time (at least I don't think they are). I really think JasperDale's got it with the frost damage, that would have been my first thought too except I'd never seen oleanders get damaged until the temps got a lot lower, but given the time of year it really makes a lot more sense for it to be frost.
I had 2 beautiful oleander trees. Both quite mature. The one in the yard fronting the street was showing signs of severe distress, which I subsequently found out was leaf scorch (and yes, it is the sharpshooter grasshopper that carries the bacterium that causes this to be such a deadly, and widespread disease). Fortunately, the big tree in the other yard (the house is between the two) has been spared, and it seems it will weather the worst of this. I had to cut down the beautiful smaller tree...However, it is showing signs of life, with new growth everywhere from the stumps. Since the bacterium ultimately kills the tree by literally sucking it dry, causing the leaf scorch, I hear that keeping it well-watered does retard the spread of the disease. It truly is heartbreaking to see these beautiful trees dying everywhere in Southern California... although it is remarkable how many survive in close proximity to the dead - or dying - ones.
