Weird thing is that snow melt (it was fairly deep) and rain in the early spring didn't seem to cause any trouble. It seems like the drip system contributes a larger water flow than those did. Or maybe they caused enough erosion that the drip water had a path to get in... (no problems with this last fall).

Anyway, thanks, good to know that a slope towards the house is pretty universally considered bad.

I'd expect the landscaper to fix the problem they created for you.

I live in a hilly area, and it's not always possible to place a house on the top of a slope. I have a French drain in front of my house to handle heavy rain that runs off from the lawn, and I'm not the only one in my neighborhood using this solution.

Cut back on the watering time, and don't water if you have received rain. As to your damp basement, concrete is never completely dry. Water moves through it on a microscopic level. The simplest and least expensive fix is to coat the basement concrete walls and floor with a waterproofing paint. HERE is an article with more info.

It isn't necessarily the case that the landscape company that did the planting created the grade issue. One would need to know the history and the particulars of the contract. A company tasked simply with planting may not have the obligation to correct a grade issue that should have been fixed by the original builder. It might be the case that the condition existed and was simply not pointed out by the homeowner or the landscape planting company. It would have been nice and more professional/thorough if they had pointed it out and said, "For a little extra, we can take care of that." We just don't know what happened.

Nevertheless, it's probably an easy fix, depending on the severity of the problem. If the OP could quantify the problem and explain/show how grade interfaces with the foundation wall, maybe we could suggest what to do.

Yes, the landscaping company created the slope. They built a mound and then planted on top of it. It looks to me like it would be straightforward to fill in the house side of the mound so that it no longer slopes down. (The yard generally slopes down towards the street, so no problems there.)

I tried to capture the slope in my picture, but didn't do a great job. :-) Using a measuring tape, it's about 4 feet from the high point of the mound (where the tree is planted) to the wall, with about a 1 foot drop.

Would love to hear if anyone feels like this kind of slope towards a house is defensible, since the consensus so far seems to be a strong "no".

Kind of hard to describe but to show a slope you must hold the camera level and photograph perpendicular to the line of slope, and with the camera held moderately low. If it is too high, one would be looking down so cannot see the cross slope. If the company created, it would be worth pursuing them to fix. Be careful about just adding soil to correct the slope as you also cannot let it get too too high against foundation wall.

I agree with Yardvaark about the danger of adding too much soil against a foundation.

One thing that's confusing is that the verbal description ("one foot drop") in no way corresponds to the picture, which just shows flat ground. If the picture doesn't show what the problem is, it will be hard for viewers to understand or accept it.

Here's an alternate angle, hopefully clearer about how things are arranged.

The tree is the high point, dropping 1 foot to the cement wall.

I think it should be possible to fill in the downward slope while still keeping about 10 inches of cement above ground.

That totally illustrates it. I would bet that if you show a wide shot of the tree and house, the vast majority of us would say that the tree is planted too close to the house. A lot of landscape companies plant trees high, especially if the soil has much clay, on account of fear of their roots staying wet too long and rotting. This wouldn't be the problem it is if the tree was farther away from the wall. I wouldn't raise the soil to overcome the wrong flow of drainage. I would relocate the tree to a more acceptable position. (.... if my guess is right.)