singingsiren
Newly Registered
Posts: 2
Joined: Sat Apr 16, 2011 12:57 am

Help new to growing hydrangeas:Weak stems, bugs, or disease?

:?:
This is my first hydrangea and I'm trying to figure out what's going on with it. Planted it in October of 2010. It's a three year from HydrangeaPlus; Hydrangea Macrophylla Generale Vicomtesse DeVibraye. Most of it looks great from what I can tell, but a few of the upper stems looked pinched and started to droop. There are also some spots where the leaves looked burnt brown around the edges (I assumed this might just be from Texas sun exposure because all the burnt leaves are where the plant gets some late afternoon sun,although 90% of the plant is in full shade). I've been trying to find something that might explain why those few stems appear pinched and droop, but to no avail as of yet. Any thoughts? Could it be some disease? Or an insect? I haven't seen any bugs when I've looked, but insects are crafty buggers. Maybe I'm just over reacting? If there is an underlying problem I don't want it to get worse.

[img]https://jdesign.info/Gardening/Hydrangea01.jpg[/img]
[img]https://jdesign.info/Gardening/Hydrangea02.jpg[/img]
[img]https://jdesign.info/Gardening/Hydrangea03.jpg[/img]
[img]https://jdesign.info/Gardening/Hydrangea04.jpg[/img]
[img]https://jdesign.info/Gardening/Hydrangea05.jpg[/img]
[img]https://jdesign.info/Gardening/Hydrangea06.jpg[/img]

Any help would be greatly appreciated. I've attached some pictures to show what I'm talking about. Thanks!

luis_pr
Greener Thumb
Posts: 815
Joined: Sun Jul 05, 2009 12:31 pm
Location: Hurst, TX USA Zone 7b/8a

Interesting, singingsiren. A small/limited amount of wilting has happened to me before and I never found an obvious cause. I first looked for borer insects but found no evidence so I finally assumed it was caused by a windy day. The problem "went away" on its own after a few days or so.

Wilting/drooping of leaves indicates that the leaves are loosing moisture faster than the roots can absorb them. So lack of moisture, a windy day or placing the shrub in a windy location will cause this wilted look. It is very common during summer time on many hydrangeas. But most wilting episodes involve almost the whole shrub, not just 2-3 leaves.

If the wilting episode looks extreme, water ½ gallon of water immediately and ask questions later. Otherwise, insert a finger into the soil to a depth of 4" and if it feels almost dry or dry then water 1/2 gallon. If the soil feels moist or wet, do not water ..... instead, check the hydrangea again in the morning. If still wilted in the morning, water 1/2 gallon.

You can use the finger method in order to determine when to water. Check the moisture daily for two weeks. For a "new" hydrangea, water 1 gallon of water if it feels dry or almost dry. Each time that you water, make an entry in a wall calendar. After two weeks, review your calendar notes and determine how often you are watering (once every two/three/four/etc days for example). Then set your sprinkler to water 1 gallon of water on the same frequency. If temperatures change 10-15 degrees and stay there, re-check using the finger method for another two weeks.

Wilting can also be a sign that the roots are rotting. When the roots rot, the part of the shrub above ground does not get enough moisture and you get wilting of the leaves. It is hard to differentiate by wilting from lack of moisture or wilting due to root rot. That is why it is important not to water too much.

Root rot normally affects the whole shrub or almost the whole thing. Since your problem appears to be limited to just a few leaves, I would monitor the hydrangea and its soil moisture closely. For now, assume it is either too windy or that it needs more moisture; water according to the finger method.

Regarding your other questions/observations, when hydrangeas get insufficient moisture, the leaves brown out starting at the edges of the leaves so again, keep an eye on soil moisture.

Too much sun shows up as complete yellowing of the leaves. They turn all yellow or white-ish. To prevent this, I plant hydrangeas here such that they get shade starting at 11am-12pm.

Hydrangeas are not bothered by too many pests but there will be some that take a bite and move on. As long as the issue is small and limited as you see, I would take no action. But you could release some beneficial organisms like Lady Beetles, etc

Does that help you, singingsiren?
Luis

singingsiren
Newly Registered
Posts: 2
Joined: Sat Apr 16, 2011 12:57 am

Sorry. I didn't get back to this sooner. I'm a bit scatter brained. Thanks you for the info luis_pr. Your reply was helpful and I appreciate the info. Hydrangea's doing fine other than us not realizing that it would be in full sun most of the day in the summer :shock: So now we have an umbrella covering it until fall when we can transplant it. :)

luis_pr
Greener Thumb
Posts: 815
Joined: Sun Jul 05, 2009 12:31 pm
Location: Hurst, TX USA Zone 7b/8a

Do not feel surprised. It happens often since the angle of the sun is different. And with temperatures now in the 100s often, wilting will become more common so keep an eye in the mornings to see if they remain wilted.

I have had to add water once to hydrangeas and twice to azaleas in addition to the regularly scheduled sprinkler waterings. One time, the whole hydrangea shrub looked the end of your wilted stems so welcome to summer, hu?

Luckily, temperatures should finally dip into the 90s this week! :shock: Oh lord.

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