What is the best material to use and manner to build flood irrigation berms?
As a general rule berms should be three times as wide as they are tall for them to hold up. A heavy clay soil is usually a great material for the berms. Planting some grass on them helps to prevent erosion as the roots get set into the berms they provide stability. Keep the berms free of leaves and other debris that will cause erosion or failure points, thus leaks!
Is there something or some way of keeping the weeds down in my berm? I get a lot of grass and weeds.
Adding mulch and edging can drastically reduce the amount of weed growth in your berm.
Do you have any articles with pictures or ideas for planting and designing landscaping berms?
These articles should help: https://www.gardeningknowhow.com/special/spaces/building-a-berm-how-do-i-make-a-berm.htm
We just bought a house with lots of lawn and the desire to transform lawn into more interesting landscape features. We have some good fill dirt from creating egress windows in our basement, so we thought this would make good berm material. My question -- is it necessary to remove the sod before creating the berm or can we just pile material on top?
You can just pile the soil on top. The lack of sunlight will kill the grass. Here's an article that will help with designing the berm: https://www.gardeningknowhow.com/special/spaces/building-a-berm-how-do-i-make-a-berm.htm
I see berms that look like their edges are so even and easy to mow around. Is there a trick to making it look professional?
They likely used an edging when they built the berm (and removed the edging after). You can go back and edge a berm to even it out much like you would edge a flower bed.
Very long, very steep, very dry part of it flows into my lawn, part of it flows into bark covered area with pine trees. Center of bark covered area has rock landscaping. I cannot mow any longer, and the area is too steep. I like the protection and visual privacy but need to find a way to make it low maintenance. I would like to cover it with shredded bark as I think it would fit nicely into existing look but it is steep and long and would be costly to maintain. If I use a rock or gravel cover, it competes with my yard too much. Can you help me?
Shredded bark/wood usually works well on berms, as it is less likely to wash down during heavy rains. You could also take out the weedy growth/grass and replace it with some low-maintenance native plants.
What types of plants could be grown on a berm in a semi-sunny area of the yard in Florida that could prevent soil erosion?
Vinca minor is a popular choice for this kind of thing. It spreads quickly and holds hillsides together well. The plants in this article would also do well in berms: https://www.gardeningknowhow.com/special/slope-hill/hill-ground-cover.htm