Building a berm or mound isn’t as complicated as many would think. By following simple guidelines in the design of the mounds and berms, landscape troubles can be eliminated with ease.
If you’re one of those wondering “How do I make Landscape Mounds and Berms?” read on to get an answer.
Landscape Mounds and Berms Design
Before building a mound or berm, a landscape designer should first plan its design. You can also design it for yourself. Always consider the mound’s overall purpose in advance as well as the drainage patterns within your landscape. One “purpose” could be a spill containment berm.
On average a garden berm or mound should be about four to five times longer than its height, progressively streaming out into the remaining landscape.
Most landscape berms have a height of 18-24 inches. The berm design can have more than one peak to give it an added interest as well as shape to perform its purpose.
Most of the berms are given a curved or crescent-looking shape, which is preferable and natural looking.
Related Reading: 37 Landscape Edging Ideas
Build A Berm Or Landscape Mounds
Berms are often constructed using fills such as plant debris, sand, asphalt, soil, or rubble. Use the fill materials to fill the major part of the berm, forming its shape around it using the soil. Firmly tamp the fills to ensure compactness.
The LandscapingNetwork has this Pro Tip:
When grading mounds near existing trees and shrubs, never alter the grade nor disturb soil within a tree’s drip line. Also be sure the berm will not interfere with water that has previously supported the life and health of the tree.
The Following are the Items You’ll Need to Have When Building Landscape Mounds and Berms
- Graph paper
- Landscaping spray paint
- Garden hoses
- Clay soil
- Fill dirt
- Boulders and flagstones (optional)
- Shredded bark mulch
- Various plants
The Following Ten Tips of Building Landscape Mounds and Berms Will Guide You Better
Sketch The Berm Design To Scale On A Graph Paper Beforehand
Having a sketch of the berm to scale will help you become aware of the area the berm will occupy so that you can know whether you have enough room to build it.
Berms meant to showcase trees should take a horizontal slope of 5-7 feet with 1-foot height from the base while those meant to showcase small plants can do well on a steep slope of 3-4 feet in length with a height of 1 foot.
The peak of your berm should be designed to occupy one end instead of taking the center position. Also, the top of the berm should be flat to prevent water run off to the sides of the slope.
Be creative with the design, such that your berm has multiple peaks, undulant conical edges, or even crescent shape, rather than the perfect oval design
Put Down Your Layout Plan
Lay out the berm design on the ground using the garden hose; garden hoses are preferred because they flex easily to achieve perfect curves to layout an island bed and also offer flexibility in the design.
After you’re content with the shape of the berm, transfer it to the lawn using a landscaping spray paint.
Remove The Turf Layer In The Marked Lawn
Use your spade to remove the turf clutter so that the marked turf is now ready for refilling. Curve it with grass, if possible, so that you can be able to see your design as you fill it up with dirt.
Fill The Area With Clean Dirt To Build Up The Berm
Use a garden hose to spray the mound so as to moisten the soil and then tamp it tightly. The fill dirt should take up about half of the total height of your berm. The remaining part should be filled with top soil.
Fill The Remaining Few Inches With Clay Soil
Depending on the height of your berm, cover up the fill dirt with 1 foot of clay soil. Any other correction in the berm design should be made using clay soil.
Clay soil is preferred as it compresses well and it’s not likely to be eroded by runoff water.
Add Top Soil Over The Clay Layer
Bulk up the remaining height of your berm using topsoil; this will provide nutrients for your vegetation.
Use A Shovel To Flatten The Top Soil Of Your Berm So That It Can Take A Good Shape
Drag the topsoil using a bow rake down to the outlines of the berm to achieve significant slope and smooth edges. Compress the top soil especially on the sides of the hill to ensure that it’s compact.
Naturalize Your Berm
Place large boulders and flagstones throughout the berm to give it a more natural outlook. Bury one-third of the stone height to hold them firmly in the soil, and also to make them appear as natural features on the hill.
Plant Your Vegetation
Plant the vegetation of your choice be it trees, perennial and annual flowers, groundcovers and shrubs on the berm so that they can establish roots to anchor the soil, especially on the sides of the slope.
Plant the short plants at the peak of your berm; this will make them more visible. You can have several trees at the top of your berm as well, but plant them in an irregular pattern so that they can look natural.
Plant the groundcovers at the slope of your berm to help preserve the soil from being eroded.
Add Mulch Around The Plants
Add a 2-3 inches film of mulch around the plants on your berm; use mulches with uneven shapes to prevent erosion. Shredded barks can make good mulch as they interlock to resist washing down the slope.
The Bottom Line
There are no specific rules for building a berm. The landscape outlines will dictate much of the berm or mound’s design as the rest lies with the owner’s needs and preferences. Be creative and unique.