Many parts of the country are having abnormally high temperatures. That is definitely the case here where I live in Oregon. We're seeing temps in the mid to upper 80s and there's been some talk of us hitting 90 this month. For this part of Oregon, that is just crazy. We should be in the 60s and 70s right now.
For those of us who container garden, that means lots of watering. The plants haven't grown strong enough roots yet to be able to seek out all the water in the pot and the plants aren't strong enough yet to deal with this weather. That means a lot of wilting, shock, and possibly death. So how do you deal with this?
Go out first thing in the morning and give everyone a really good watering. Make sure not to miss anyone. Doing it early in the day before it gets too hot out decreases the amount of water lost due to evaporation and allows it to seep into the dirt.
Put mulch around your plants. Several of my pots have mulch all around the plants. Home Depot has been running a special lately on the weekends where big bags are only $2/each. I bought three, which appears to be way too much for my garden. Having never worked with mulch, I didn't realize that a little goes a long way. And be sure to have gloves as well, otherwise you will end up like me and be covered in slivers. I like working in the garden with my bare hands, but not with mulch! Adding mulch helps to keep moisture in your pots longer, which means they can better make it through these hot days.
Check on your plants during the day. If it's extremely hot outside, you may find some plants need a second watering. Just be careful, as you don't want to overwater and wash all your nutrients away. You can look at the soil and see how dry it looks, is it pulling away from the sides of the pot, etc.
Hopefully all of this will help you to protect your plants during these heat waves.