It is very common for acid-loving shrubs to need a "booster shot" sometime between July and September. Such booster shots need to be applied per the recommended label schedule until the problem goes away, which can take as little as 1-2 weeks or slightly more than a month. Make sure you dilute the products per the label amounts too.

Since our acidity levels are somewhere around 7.4 or higher, you could apply these monthly, all year around to reduce or elimintare the outbreaks.

Other products that you can apply are garden Sulphur, aluminum sulfate, iron sulfate or green sand. Other liquid iron chelated liquid products are fine too. I usually waterever is handy when shopping. Just make sure that you do not apply aluminum sulfate near azaleas because that can poison them if applied in large amounts.

Luis

Thanks Luis.

Also - is it time to drop back on the watering? I've been watering every other day for 30 minutes (drip line) for the hydrangeas at the lake (due to high winds and very sandy soil) and every other day for 15 minutes (drip line) here in the city.

Normally, we can do that but this is not a normal year. The exceptional drought continues and they think La Nina will return again, meaning the drought may not abate. Except for some rains that brought down the temps from the 100s, we have not received any rain so I suggest using the finger method.

Insert a finger into the surrounding soil to a depth of 4" daily for a week or two and write a note on a calendar on those days that you water. Water if the soil feels dry or almost dry. Then set the drip to apply 1 gallon of water on the same frequency that you were watering with the finger method.

Further down in December, we may be able to reduce that since most or all acid loving plants will be dormant. Hydrangeas vary but, over here, usually go dormant between November to December (when the foliage and blooms completely dry out). My hydrangeas currently look like they are still watching late night TV.