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Sunday - July 26, 2015

From: Lufkin, TX
Region: Southwest
Topic: Pests, Shrubs
Title: Hydrangea with Pest and Sun Issues
Answered by: Anne Van Nest

QUESTION:

My hydrangea is in trouble. Something is eating holes in the leaves which then turn brown on the edges (the holes and the tips of the leaves are also burned). It looks like someone burned them with a cigarette. I don't see any insects. I took a picture to send but don't see where I can add it. Is it insect damage, soil problem or just too much hot sun? I moved it today to a shadier location in hopes that resolves the issue. Help! Thanks! (I'm in Lufkin and it is sunny and HOT!)

ANSWER:

Neil Sperry in the Star-Telegram has written a good article about The challenges of growing hydrangeas that you might like to read.

Here's some of what he says about Hydrangeas in East Texas....

In my own experiences, hydrangeas grow best where they receive morning sun (until 10 or so) and shade the balance of the day. In areas with black, alkaline soils, they should be planted much like azaleas. Dig a hole 15 to 18 inches deep and 3 feet wide for each plant.

Remove all of the native soil. Fill the hole with a mix of half sphagnum peat moss and half finely ground pine bark mulch, and mound more of that mix to 12 or 15 inches above the surrounding grade. That will give your plant good drainage and an acidic growing medium. You will need to water it slowly and carefully, however, because the mound will tend to shed irrigation and rainfall.

Hydrangeas dry out more quickly than almost any other shrub that you’ll grow. That’s partly because they prefer moist soils and cooler summer weather, but it’s also because of their very large leaf surfaces. It simply takes a lot of water to keep them plumped up and happy.

And since local irrigation water tends to be highly alkaline — not the friend of hydrangeas — you may see signs of iron deficiencies showing up. Iron is insoluble in alkaline conditions, and it’s a critical part of the chlorophyll molecule, so when alkaline irrigation water combats the original acidity of that planting mix you prepared, you can expect iron chlorosis to appear after a few years.

On the plus side, very few insects or diseases bother hydrangeas.

You’ll want to trim and reshape the shrubs only after they finish blooming. Try to do as little pruning as possible, though. Strong vegetative growth made late in the growing season can come at the cost of having no flowers the following spring.


Read more here: http://www.star-telegram.com/living/article17958428.html#storylink=cpy

 

 

From the Image Gallery


Smooth hydrangea
Hydrangea arborescens

Smooth hydrangea
Hydrangea arborescens

Smooth hydrangea
Hydrangea arborescens

Oakleaf hydrangea
Hydrangea quercifolia

Oakleaf hydrangea
Hydrangea quercifolia

Oakleaf hydrangea
Hydrangea quercifolia

Oakleaf hydrangea
Hydrangea quercifolia

Silverleaf hydrangea
Hydrangea radiata

Silverleaf hydrangea
Hydrangea radiata

Silverleaf hydrangea
Hydrangea radiata

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