Watering perennials in the hotest part of summer

by Alvina
(Perry, OK noble county)

What is the best rule of thumb for watering perennials that like full sun in the middle of summer? I am having a hard time keeping them looking good.

Thanks

Doug says there are actually two problems here with "looking good".

The first may be watering. Generally, 2 deep waterings of 3/4 to 1 full inch a week in well-drained soils will keep a perennial bed well watered. I find with a deep mulch that I wind up not watering most weeks but when I do have to water, I put on an inch or two at one application to get it through the mulch. With mulch, check the soil moisture by pulling back a bit here and there and feeling the ground with your finger. If damp, don't water. If drying - soak thoroughly. Without mulch, you need to continually apply 2x a week.

The second thing that happens to plants is heat problems. Many perennials can't take extended periods of high heat (photosynthesis shuts down in mid-80's on them) and they get tattered looking no matter what amount of water you toss at them.

So I'd expect a tired-looking garden in mid-summer in high heat areas unless the garden is totally high heat tolerant plants.

Hope that helps a bit.