Drought makes water priorities clear

Don't give up! Do give water to the weak and the edible

It is hard to keep from crying when the landscape turns crisp around us and no amount of water is enough to replace what the plants lose to blistering heat.

So, choose your targets and water wisely.

Do all you can to keep it moist if:

It's an important tree or shrub that had to replace much of its foliage this spring after suffering frost damage (many Japanese maples and mulberries, and a good number of unluckily situated ginkgoes, katsuras and others). It already dipped into its reserves to create the replacement leaves. Now, if it's crown is thin, it's not producing starch in its customary amount. Let it remain dry and you may see significant dieback next spring.
It's a vegetable setting fruit or forming tubers now. They may be miniscule but that produce is susceptible to blossom end rot (tomato), fruit drop (apple, peach, nut crops, etc.) stunting (potatoes), etc.
It's a plant stressed by other factors, such as your favorite rose exposed to exhaust vents, or chemical spray drift when lawn care companies visit. (What in the world are lawn companies doing, to be continuing with fertilizers and pesticides on dormant lawns and around vulnerable ornamentals?!)

We planted potatoes 60 days ago. They are almost certainly in tuber formation stage right now, when steady water can make a crop and drought can ruin it. It's worth carrying a bucket of water every day or dragging the hose, for homegrown potato varieties not often found at market.

Many ways to deliver water

You don't have to water the whole yard or a big area.

Pour a bucket of water slowly over the plant's root zone

Let a hose drip there for an hour or two.

Cover the soil with mulch, if it's bare.

Set a full but leaky bucket or jug firmly onto the soil.

Up-end long necked bottles filled with water to seep into the root zone. (More in Growing Concerns 311.)

(See What's Coming Up 151 for details.)

On the other hand,
don't waste time on terminal cases

If it's in permanent wilt and won't "come to" no matter how much or when you water, lay it to rest. When plants are severely stressed, all manner of pathogens and pests home in on the weaklings' distress signals. Don't make matters worse for the survivors by allowing a build up of infected or infested material.

Hydrangea's had it

Right: This plant has had it. When it has been too often left dry and hot, cool moisture loving Hydrangea develops a chronic wilt that is likely the root rotting disease called armillaria. When this happens no amount of water can bring it around. The owner reportsthe plant has been wilting regularly since before summer went dry, so it was a goner from the get-go.

Below, right: It probably didn't help the plant when, several weeks ago, chemicals meant for the lawn drfited onto the leaf. White residue remains to tell the tale.