Can you post a photo or two? You can regrade the yard. Plant trees and shrubs that will help absorb water. Install a French drain system. Install a retaining wall. Redirect downspout further out into the yard. Without knowing what your situation might be, any of these options will work.
Is this erosion along a beach, a lake or just from excess run off in a yard? In general here are a few ideas.
Plant trees or shrubs near slopes or shorelines.
Plant a rain garden so soak up excess moisture.
Mulch when possible.
Build a terrace or retaining wall.
Use a rain barrel to contain water coming from a spout drainage.
what is a rain garden. It is excess water when it rains that comes down into the many slopes
Naomie has the right idea.
Naomie is right. You don't say why or how your ground is eroding so it is difficult to suggest the best way to help. Also, is it washing away badly or just gradually? Is it on a slope or hill? Is it a constant thing or only when it rains badly? I have a slope in my lawn that I have planted shrubs and small trees in. It is in a full sun location but when it rains all the water runs off here. I have also planted a ground cover around the shrubs and trees. All of the plants roots have helped hold the soil in place and it looks good.
Yes it is on a slope and the roots are showing from the many trees. When it Raines all the water comes down to the flat area and now I have very little grass left. A few days ago I planed grass seed and then it rained and all I could see is puddles where I planted the seed. We tried filling the slopes with mulch but it did not help much
Anything in the willow tree species will soak up water like crazy.
What do u mean. Plant willow trees?
Hmm, your slope is obviously steeper than mine. Yes, willows do draw a lot of water but if this only happens when it rains I'm not sure the willows will do well during any prolonged dry spell. How about a rock garden with some flowers and shrubs planted amongst them for color and interest? You could group various sized rocks in interesting arrangements and then plant different plants around them. The rocks and plants might slow the flow. I have a drainage ditch along the road side that floods used to flood badly and I planted a tree/shrub (don't know what kind of tree it is as it was wild and just sprouted on the back side of the house, I moved it to the ditch) and Yucca plants in the middle of it. They have grown a lot due to the amount of the water they get and my neighbors yard and driveway is no longer being washed away. I live in south Virginia so Yucca plants do well here, I'm not sure where you are or if they would work for you. May want to check with your local agriculture center to see what they would recommend.