All the water runs off and it seems plants are doing poor from lack of water.

Should I drill holes in the slope and put drilled PVC pipes in the holes to catch the runoff? Or what do you rec?

Make a basin around each plant to catch the water.

sort of like a bowl, but with the biggest lip on the down slope side.

You can use dirt or mulch

If you do it right, you should be able to water with a hose so that a tiny lake forms at the base of each plant.

If I were you,Alaskan, I would go with drip irrigation with slow drip or misters.

Another vote for drip irrigation.

Besides moving the soil around the plants, some strategically placed rocks help hold the soil in place.

Then there's also terracing...but that's getting a little more involved...

mulch and soaker hose or drip irrigation.