Dwarf Norway Spruces Dying
Just a quick question for everyone, I'm at a bit of a loss for what could have caused it. We did a landscape install around three weeks ago, which consisted of somewhere around 40 shrubs, 13 of which were dwarf Norway spruces. We were there last week and they all looked fine; got a call earlier this week that they were starting to turn color so we went to take a look yesterday. All 13 of them are turning brown on the top center; the rest of the shrubs are fine (grey owl juniper, Encore azaleas, fernspray cypress, arborvitae, winterberry and a topiary pine). We dug a few of them yesterday to take a look; the roots appeared to be relatively healthy; there are some small white tips on some roots where it appears to be trying to grow. One did appear to have some sort of fungus growing on the rootball.
When the client called to report the issue, they did mention that they had been watering every day. They were looking for a low maintenance landscape; I was shocked to hear that they watered it every day; especially since we have installed other landscapes for them on the property and they did not do so, though this was the most expensive. I've either told them in the past about how much to water (if needed) or they have asked, but either way this time there was a miscommunication.
That all said, the soil is a heavy clay; we did amend all of the holes with a mixture of composted pine bark fines and leaves, so they're not planted directly into the clay soil. I'm guessing the die-back is a result of over-watering, combining the recent rains here with the supplemental watering. I'm thinking too much water would result in the water pooling in the dug holes. If it were a few of them, I'd say perhaps we planted them incorrectly or it was a disease, but for all 13 to die at the same time, seems strange. Would root-rot show signs that fast, and could I still expect to see some roots growing?
I'm planning to dig a couple today and bring them to the nursery to get their input and check on any warranty, but I'm not too sure they'll cover it if it's a result of over-watering. The client insists that they did not over-water, after I brought it up as a potential cause, saying that they've planted a lot of plants in their lifetime, and that they'd expect all of the plants to show some signs. Of all of the varieties planted, I'd expect the spruce is the least tolerant to over-watering and may be the first to exhibit any problems.
Any thoughts would be appreciated!