99% of foundation issues are caused by water. Grading plays a very important role in controlling water and keeping it away from your foundation. Proper grading drains surface water away from the building and is recommended to be at a slope of six inches for the first ten feet from the foundation.
If you have negative grading where the land is sloping towards the building you should have it corrected. Pull back any landscaping materials including plants for several feet from the building. Make sure to keep soil away from the siding material. Dig down to create the positive grading. You may need to create a swale or French drain in some instances. If your property allows for adding dirt to create positive grade without it touching the siding material, I recommend a mix of brown and black dirt to keep it from washing away.
Remember to keep your gutter extensions six feet from your foundation to aid positive grading with controlling water and keeping it away from your foundation.