I may also need to add that the water is pooling above where I didn’t amend the soil, which is about a foot down below grade where the hard clay is.

When you have a bed with good soil, water that struggles to penetrate your clay will drain into it. You probably need to add drainage.

I regret to inform you, if you thought tilling in 'compost and pine bark fines' was going to improve drainage without taking any other steps, you were misled.

I dug up all the plants yesterday & decided to raise the bed. Sloped it slightly to drain excess water into the lawn where the French drain is. This evening I’ll replant everything -they’ll now be a few feet above the clay soil when planted.

James, I have a very similar issue.

I noticed that the soil around my Limelight hydrangeas & other shrubs was soggy. I moved everything to a good-quality bed until we could determine the root cause, then resolve.

• The planting bed is sandy. The holes originally dug for each shrub were big, but not large. They were filled w/good soil.
• We discovered that the planting bed sandy soil (including some clay), is as hard as a boulder in many areas. To be able to dig, our new landscaper had to use an auger & pick axe. Water does not /cannot drain. . . there is nowhere for it to go, so it sits.

OPTIONS: We considered several, including:

• Create deep berms to plant the shrubs in.
• Excavate a 2-foot depth of the hard soil from the 230-foot long planting bed & filling it w/good-quality soil. This option wasn't really feasible, because drip irrigation is already installed. ( This should have been done before irrigation was installed. )

EXPERIMENT:

• Our landscaper dug 3 holes in different problem areas of the bed. Each hole has a diameter 1' wider than is usually recommended, and is as deep as needed to reach soft sand (4') He layered dry leaves, rocks, then 3' of good soil.
• We covered each hole w/mulch, as we do for our shrubs. For 3 months, we observed how the area drained after irrigation & rain.
• It appears that the water is draining well. The planting holes are not soggy, so we're going to transplant a shrub into each of the 3 experimental holes when the weather cools here on southern shore of Massachusetts.
• I will observe the drainage & determine if this solution worked. If so, get out the auger to dig more holes!