You may not be doing anything wrong but it sounds like you are watering too much. Hydrangeas always suffer and wilt during the heat of the Texas Summer and new shrubs will do that even more often than normal. Once the shrub is established and starts growing a good root system, it will not wilt as often or as long but it still will wilt on some summer days.

Wilting a natural response by large leafed plants to circumstances where they loose moisture through the leaves faster than they can absorb moisture through the roots. High temperatures can cause wilting and so can windy days. If the weather forecast has wind advisories, you may see wilting in temperatures like the 80s. By reducing the leaf surface in contact with the hot sun, the plant looses less moisture.

To help the plant, you can make sure that it has 3-4" of any type of acidic mulch. This conserves soil moisture and prevents from having to water often.

You also need to water only when the soil feels almost dry or dry. That is a tall order when you see all these wilting episodes so here are some suggestions.

Hydrangeas wilting mechanism allows them to recover and go back to normal once the sun goes down (or next morning at the latest) so, based on that: if you see an extreme wilting episode, water immediately 1 gallon of water for a new shrub (slightly more for taller plants). If the wilting episode is "not extreme", check the soil by inserting a finger to a depth of 4" into the soil. Does it feel almost dry or dry? If yes, water 1 gallon of water (more for a larger shrub; otherwise wait until next morning. If still wilted in the morning, water.

Why do this? Hydrangea roots like constant soil moisture that feels "moist" to the touch. If it feels wet then they can develop root rot, a fungal infection that usually kills the plants. Plants with advanced root rot are always wilted-looking because they cannot absorb water through their impaired root system. It is the same symptom you normally see on new shrubs in the summer but this goes on constantly and the plant does not recover from the wilting on its own.

On a daily basis for the next week or so, use the finger method to determine when to water. If the soil feels almost dry or dry then water and make a note on a wall calendar. After a week or so, look at the notes and observe on what frequency you are watering (every 2/3/4/5/... days). Then make it part of your schedule to water 1 gallon of water on that frequency early in the mornings (or set an automatic drip system on that frequency). Recheck using the finger method if temperatures change by 10-15 degrees (up or down) and stay there.

Location - the planting location is critical here. I find that shrubs that receive sun after..... let's say after 11am approximately, will get sunscald. The leaves will turn all yellow, including the leaf veins. So select a planting location that is not too windy and that gives them shade starting at about that time or earlier. Dappled sun is fine too. You do want some sun as this makes the plants flower more. A minimum of 1-2 hours will be fine, even less in some special conditions.

FYI: If the leaves begin to brown out, this could suggest too little water so keep an eye on the shrubs during this tough time. ES should make it through. Some time after October and as late as December, the plants leaves will dry out and go dormant. Remember to water them while on the pot during winter!

Does that help you, dallasblooms?
Luis

Wow, thanks for such a detailed response Luis! I do have acidic mulch on top and have dumped coffee grounds on it occasionaly too. I did not know about the wind being an issue - it's extremely windy on the porch when we get a storm, but dead calm otherwise. I checked the moistness and it's still wet so I will hold off until 4" are mostly dry as you suggest. It looks even worse this afternoon than it did this morning - wilting AND dry leaves - so I may be too late on this poor plant. It probably has root rot based on your description, but I think I'll move it to the front porch where it's more sheltered from rain and wind. Maybe it will dry out. If nothing else, I now know what to do with the next one I buy. Thanks again for the valuable information.

You are welcome and good luck.

I've been having exactly the same problem as Dallasblooms. I live in northern California where the summer heat of 85-100 has really taken it's toll on my newly planted Endless Summers. I think I'm overwatering them to keep them from wilting at all. If wilting is normal then I think I may be drowning them. Also, I have some in places that get too much sun and must move them this winter.

My question is about drip irrigation. We never have rain between May and late October, so we have drip irrigation. How close to the base of the plant should I put the drippers? I think I may be too close and in danger of drowning them.

I also have new Oakleaf Hydrangeas nearby. They like the additional sun, but again I'm drowning them. I see now that I need to cut the water back on them since they don't like wet feet.

Lastly, you suggest acid mulch. I have about 3" of redwood mulch on all the hydrangeas. Is this a good type?

Thanks so much.

Debbie

Hello, Debie. Where to place the dripper probably differs based on the type of soil that you have, how big the roots are and whether the dripper's water can reach the roots.

The amount of area wetted by the drippers always resembles a balloon. If you have clay soil, the balloon would look wide and not too long/deep, almost like a baloon full of air about to explode? If you have sandy soil, it would be thin and long/deep. The wetted area should wet the plant's roots. You can put it right on top or besides.

I place one dripper right on the main stems of the shrub. As the plants grow, I add more tubing to cover areas not being wetted. Because this is a slow-release watering method, you do not need to worry about 'drowning' the plants provided your soil drains well.

This works well with plants like hydrangeas but I do not recommend it for shrubs like azaleas and rhododendons who have most of their roots on the top 4" of the soil. The tubing that is provided has drippers every 12" and this is not enough coverage for plants whose roots stay near the surface.

It also may not work well when a new plant is located a certain distance away. If the plants does not have deep roots yet (because it is new) then water from the dripper may not reach the roots and the plant dries out! even though a dripper is just 6 inches away. That happened to a small gardenia of mine once. It had very few roots and the dripper was about 10" away. The root ball dried out because I forgot to check it out.

I am not certain if redwood mulch is acidic, Debbie. I have never run into redwood mulch or if I did, it did not register in my brain. Redwood mulch is not a product of the tree that is native on the West Coast so it may pay to look on the bag for some indication. Acidic mulches may use the word 'acid' or 'acidic' somewhere in the bags or they may say that they are good for plants such as azaleas, rhodies, camellias, hydrangeas, etc.

Luis