The easiest way to prevent salt damage to your landscaping is to not use it. However, this is not possible for most people, as walkways need to be safe for everyone, especially children and the elderly, to walk on. There are a few other ways to prevent salt damage though.
Check what type of de-icing salt you use. There are some brands that do not have sodium in them. As mentioned in a previous post, the salt that has sodium chloride breaks down when dissolved and is more harmful to your plants and lawn.
Mix your salt with other materials. You can use sand, sawdust, or cinders to mix into your salt. These materials will provide grit so you will still have traction, and they are more eco-friendly.
Carefully apply the salt. Make sure that the salt is only put on your walkway or driveway. Do not freely toss handfuls around, that will cause more damage to your yard. Also check your yard to see if it drains properly. Try not to plant anything besides grass in low areas where water may gather, not only will this be where salt drains to, but excess water in the summer months can also damage your plants.
Put in barriers around flower beds. You can edge around your beds with plastic, wood, or metal edging, Not only will this prevent excess runoff of salt, but it keeps the perimeter of your beds looking sharp in the summer months because it prevents grass from growing in your beds.
For areas of your yard that are close to roads, try to plant trees and shrubs that have a higher salt tolerance. Some Oaks, Sumacs, Horsechestnuts, Junipers, and White Spruces are just a few of the trees and shrubs that have a higher salt tolerance.