Hello all,
I hope everyone is having a great fall so far. I need some help on this one, I had this ASB in a pot for about a month and planted in ground a week ago yesterday. I noticed some grey spots on the leafs. Is it powdery mildew and if so, what can I add to the plant to prevent it from spreading? Here are a few pics.
[img]https://i288.photobucket.com/albums/ll196/mlsalcido/Hydrangeas/Greyspots3.jpg[/img]
[img]https://i288.photobucket.com/albums/ll196/mlsalcido/Hydrangeas/Greyspots2.jpg[/img]
As always any and all help is appreciated.
Thanks!
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luis_pr
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- Posts: 824
- Joined: Sun Jul 05, 2009 8:31 am
- Location: Hurst, TX USA Zone 7b/8a
Hydrangeas tend to show signs of powdery mildew as seen in your pictures. The other spots look like leaf spots, another fungal infection. While there are fungicides that you could use, it is now so late in the growing season that perhaps it is best to use clean gardening practices instead.
Do not overwater the leaves. When you need to water, water the soil instead and water early in the morning so the sun has a chance to dry out the leaves. Pick up all plant debris and dispose in the trash as it contains fungal spores. When the leaves and flowers fall, dispose of them on the trash as well. Plant shrubs away from each other to improve air flow. In severe cases, replace the mulch with new mulch. A drip irrigation system can help minimize this problem but other times, one has weather issues or water sources that cause this all the time (example, a creek or pool near the house).
Hydrangeas sort-of kind-of suffer a lot from powdery mildew. Some varieties are more resistant than others but if you have ever seen how close they get packed in garden centers, you can get an idea why this happens so often. The employees are merely trying to get them close so they can easily water them but air flow between plants is reduced and many shrubs get powdery mildew from the nurseries.
If you wish to apply a fungicide anyways, try first with a solution of 1 part milk and 9 parts water. This time, water the leaves. You can add more milk to make the solution stronger. I usually go thru one or two gallons of milk easy. When a little milk is left, I fill the container with water and water the hydrangeas or crape myrtles that have powdery mildew.
Do not overwater the leaves. When you need to water, water the soil instead and water early in the morning so the sun has a chance to dry out the leaves. Pick up all plant debris and dispose in the trash as it contains fungal spores. When the leaves and flowers fall, dispose of them on the trash as well. Plant shrubs away from each other to improve air flow. In severe cases, replace the mulch with new mulch. A drip irrigation system can help minimize this problem but other times, one has weather issues or water sources that cause this all the time (example, a creek or pool near the house).
Hydrangeas sort-of kind-of suffer a lot from powdery mildew. Some varieties are more resistant than others but if you have ever seen how close they get packed in garden centers, you can get an idea why this happens so often. The employees are merely trying to get them close so they can easily water them but air flow between plants is reduced and many shrubs get powdery mildew from the nurseries.
If you wish to apply a fungicide anyways, try first with a solution of 1 part milk and 9 parts water. This time, water the leaves. You can add more milk to make the solution stronger. I usually go thru one or two gallons of milk easy. When a little milk is left, I fill the container with water and water the hydrangeas or crape myrtles that have powdery mildew.
Umm OK forgive my ignorance but Milk like in Milk does a body good? If yes, how does this help with powdery mildew. Also, so the solution is just milk and water? I don't have a drip line but am starting to think it will be a good idea to add one. Can I purchase from any garden center? Sorry for all the questions.If you wish to apply a fungicide anyways, try first with a solution of 1 part milk and 9 parts water. This time, water the leaves. You can add more milk to make the solution stronger. I usually go thru one or two gallons of milk easy. When a little milk is left, I fill the container with water and water the hydrangeas or crape myrtles that have powdery mildew.
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luis_pr
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- Posts: 824
- Joined: Sun Jul 05, 2009 8:31 am
- Location: Hurst, TX USA Zone 7b/8a
Yes, there are some very effective "green" or "organic" fungicides out there. Just plain old milk on a solution of about 1 part milk and 9 parts water. Some people use a stronger mix (half and half) for more severe infestations. The only downside is -sit down- pets; some dogs and cats may start to visit to lick the shrub's leaves. One of my three dogs showed this type of interest in prior years but I have not caught her licking some roses and CMs that I sprayed. The active ingredient in this case would be the pottasium phosphate in the milk.
I have also seen garlic used (sparingly as it can kill beneficial/good insects): 10 cloves of garlic in a pint of water (strain the solution when spraying the leaves).
Drip systems can be purchased from Lowes and HD. I had mine installed though when I needed major repairs to the old sprinkler system that the house came with.
If your shrubs are new, you may want to wait until next year before investing in drip irrigation. New hydrangea shrubs may have gotten powdery mildew at the nursery (when the containers were kept too close together) so PM may be less of a problem in your garden in future years.
I have also seen garlic used (sparingly as it can kill beneficial/good insects): 10 cloves of garlic in a pint of water (strain the solution when spraying the leaves).
Drip systems can be purchased from Lowes and HD. I had mine installed though when I needed major repairs to the old sprinkler system that the house came with.
If your shrubs are new, you may want to wait until next year before investing in drip irrigation. New hydrangea shrubs may have gotten powdery mildew at the nursery (when the containers were kept too close together) so PM may be less of a problem in your garden in future years.