New DE user, DE question

Ok, I'm in the process of converting from a cartridge filter to a DE.
A co-worker gave me an old Hayward EC-40 DE filter.
I have to take it apart and see if all of the parts are their.

Regarding DE. when backwashing where do you guys empty the water? on the ground into a flower bed in a bucket?
I'm worried about excess DE in the yard. The area around the existing pump and filter is a raised mulch bed, due to dogs and the mud and bare dirt that was their previously. So I put down landscaping cloth and mulch and built a raised bed around the pool.

If I backwash into the mulch how much DE will there be? Or should I use a bucket and empty into a flower bed or other area in the yard.

Can I come watch when you backwash into a bucket? :)
DE is good for the soil, actually, it's great for the grass since it is what's used to kill grubs, so if you have grubs, you now have grub control.
Backwashing into mulch isn't going to go well, a gravel bed is much better.
Can you dig a 5" deep discharge bed for holding gravel, then have that spill over into the lawn or yard? that would be much better than washing all you mulch away every time you backwash.