It's not always necessary to trim or loosen the roots of pot grown shrubs but if the roots are entwined and looping around the sides of the root ball, then it's best to cut or gently loosen them to allow them to expand outside the shape they've taken.

It's more likely that you've got some other problem that caused the quick demise of the plants. Lack of water or over watering are the two most common causes of rapid plant death. Newly planted material requires about 1" of water a week and it must soak down to the root zone to be effective. Too much water can kill just as quickly as too little. It prevents air circulation from the roots which essentially drowns the plant. So if the plants were healthy when you put them out, look to the soil moisture content first.

Did you dig large holes for them or just the size of the root ball? What's your native soil like? Sandy, hard packed clay, rocky, decent loam? Did you amend the soil with anything or add any fertilizer?

Since some of your plants are already stressed, I wouldn't dig them up unless you remember them being badly root bound. Where did you buy them? A "big-box" hardware store or a reputable nursery? Wherever you got them, check to see if they have a warranty on their plants. Some places will replace the plants if they die within a year. Some won't.

If you think the water situation was ok, take samples of the stressed plants to your local cooperative extension office to see if they can diagnose the problems. If there's some disease or insect infestation, they will probably be able to help you and their services are free.

Lastly, did you have that nice mild winter and then a nasty cold snap? That can stress the plants and kill new growth that hasn't had time to harden off. Are the branches totally dead or is there still some green if you scratch off a little bark? If there's still a green layer under the bark, they probably will survive.

Good luck with your landscape problems. I know how frustrating it can be to have beautiful plantings that die. Been there and done that myself.

Thanks for that great reply. We did return the dead shrubs to the nursery - 50%. We have a lot of clay in this area. I did amend the soil with a little peat moss and compost. When we pulled them out of the ground some of them looked like they were still in a pot. I did dig the hole plenty wide and deep, being careful not to plant them too low. I have been told that if you bury the 'neck' bad things can happen.
I am afraid maybe I did over water. I hit them about 3 days a week and I gave them a good dousing with the hose each time. Being that we have all this clay - I bet the water pooled in the holes. How do I know what an inch a week is?

Thanks again,

Chris.

That's a hard question to answer. Usually, one good watering a week is sufficient. When I plant shrubs, I make a shallow saucer shape just outside the bounds of the pot they were in and fill that with water, let it soak in and then fill it again, once a week. That seems to be enough without drowning them and I have nasty clay soil, too.

By the way, don't use much peat moss, or none at all. It can make the soil very difficult to get wet if it ever dries out. (Voice of experience here... One azalea border was heavily amended with pm and it took several years for it to get over it. Even rain didn't want to soak into the ground!)

If you want to spend the time and energy, you could dig a hole about the size you would for the planting, line the bottom with something like plastic and run the hose in it till there's about 1" of water in it while timing the event. Personally, that's being a little overboard but if you're really unsure about the amount to use, it might help you. And then you have to allow for any rainfall you get.

For the home gardener, watering is not an exact science but rather a seat-of-the-pants feel for what's enough but not too much.

To add to the above comments:

though it sounds counterproductive to many people, it is not recommended that you use peat moss (or anything) in the planting hole, no matter what kind of native soil. This practice can cause a bath tub effect, as well as discourage plant roots from ever leaving that improved hole. Amendments ARE recommended, however, if you decide to prepare an entire planting bed all at the same time. Rototilling in organic matter over a wide area is terrific. My favorite soil amendments are compost, composted wood chips, bark fines. I, too, avoid peat moss.

Another common mistake is that of planting too deeply, especially into clayey soils. It's not simply a matter of burying the 'neck' of the plant....the top of the natural root ball should be above the soil level in it's new home. Then the plants can be mulched.