Hello, wanttogarden. You did not indicate what verieties of hydrangeas you have or include pictures of the problems so I will comment in general terms to each of the five questions. I hope this helps you.

1) Many newly planted (translation: 'young') hydrangeas have stems that cannot support the weight of the blooms very well. As the stems grow older, they harden and can support the weight. However, there are some varieties that are known to suffer, especially at times when you combine lots of blooms with a rainy day. A wire mesh cage installed when the leaves have dried in fall/winter should help with this problem; cutting the flowers will not. Be careful when doing this type of pruning though; deadheading the blooms is fine but pruning the stems can cause you not to have blooms next spring. The flower buds of hydrangeas that bloom on old wood develop in the stems starting around the month of August.

2) Newly planted hydrangeas will suffer from wilting episodes when the temperatures are very warm, when the weather is windy, when they do not get enough moisture or when they develop root rot. Provided we are not talking about a root rot problem, hydrangeas recover quite quickly on their own, usually by sun down, definitely by the next morning. I suggest that you try to control the urge to water as too much water can cause root rot. If the plant looks extremely wilted, water it immediately. Otherwise wait until next morning.

To determine if you need to water, insert a finger into the soil to a depth of four inches and see how the soil feels. If the soil feels wet, check what caused the soil to be wet and take any appropriate action to improve drainage. If it feels moist, do not water. If it feels dry or almost dry then water about 1g for a small plant (more for taller/older plants). Repeat this procedure if the temperatures vary by 10-15 degrees and stay there. In the spring, water the plants with about 1g of water. At the start of the summer, you will need to increase the amount/frequency of water; at the start of fall, you will need to reduce the amount/frequency of water; and remember to water during dry winters if your soil does not freeze. Something else that will help is to maintain about 3-4 inches of mulch through or past the drip line.

Plants whose leaves turn lighter green, yellowish or whitish could be suffering from too much sun. In your area and mine, hydrangeas should be in part shade which is defined 4 hours of sun or less (mine get about 3 hours). Leaves that turn lighter green or yellow but whose veins remain green are suffering from iron chlorosis and usually just need liquid iron chelated products and/or more Sulphur added to the soil to raise the soil pH Level.

3) I am not clear what caused the plants to loose their leaves but I am not surprised that the ones in more sun are performing better. Sunlight is required to produce blooms and the more any plant gets within reason- then the more a plant thrives and the more bloomage you can expect. Plants in denser shade would show the opposite: less vigorous growth and less blooms. The leaf problem appears to be either a fungal infection or watering issue. Common at this time of the year are leaf spots and Cercospora. Neither is lethal to the plants but they can look ugly. The fungus could have originated in the nursery or been already in your garden. However, I am surprised that things got bad enough where ALL the leaves fell off though. Fungal infections usually indicate that there is too much moisture in the area where the plants are located while lack of water can make all the leaves brown out and fall.

I hesitate to suggest a fungicide at this point. It is kind of late in the year for that and I suspect you may be watering too much and making it easy for the spores to develop. For the next 1-2 weeks, manually check whether the plants need to be watered manually (as I described earlier). After a while, you will notice that you water on a certain frequency (every two/three/etc days). Set the sprinkler to water on that frequency. Try to water early in the morning and try not to get the leaves wet (water the soil instead).

It is important to remove plant material from the vicinity of a planting. Dead material (leaves, flower parts, etc) that could harbor spores of fungal disease should be thrown in the trash, not the compost bins. Make sure you do not crowd the hydrangeas with other plants; you want good airflow around the plants in order to minimize the chance of fungal infections. I cannot 'see' the extent of the infestation; if you deemed it to be large then also consider replacing the mulch that you have with new mulch.

I would not be concerned about the size of the leaves. The plants should be getting ready to go dormant so the leaves will dry off and fall off soon. Lack of sunlight and plant vigor causes them not to develop as large in late September.

Another problem that could cause the leaves to brown out and fall would be lack of water. If a plant does not get enough water, you would notice that the edges of the leaves start to brown out. Eventually the whole leaf browns out and falls. I wonder if the plant suffered from insufficient water but now is getting too much water and that caused a fungal infection. Is there any chance that you could post pictures of affected areas or can you email?

4) Same comment as above in #3. Fungal infections Âusually- do not cause all foliage to fall. Lack of water would do that in a heartbeat. You should be able to eliminate lack of water as a cause if you check the soil daily as I described above.

5) Address the problems with some of the suggestions given here and keep us updated of what happens. Hydrangeas grown in just a few hours of sun a day should be able to do well in your garden. Locations that are densely shaded are not the best though; try to get indirect reflective sunlight from a wall or cement driveway, for example. If you cannot get any sun, observe how the plants thrive and bloom before considering replacing them. Because your plants are stressed, one final suggestion: no pruning and no fertilizing. Fertilize with ¼ to ½ cup of manure or cottonseed meal in early May and again in early July. When absolutely necessary, prune after the plant has bloomed but before August.

Does this help you, wanttogarden?
Luis

My goodness Hydrangeas are more finicky than roses. Yes. I will try to keep an on water and fertilizing.
And next time I have a problem, I will be arm with pictures too.

Well I guess this is all I can do until next spring. Talk to you guys then.