The biggest concern I would have is the Bermuda. It is so invasive that even a small pinhole in your barrier will allow it to invade. So make sure you really get an sealed barrier, especially if the Bermuda is under your raised bed. The problem of course is that if you seal your bottom so well that Bermuda is kept out then you have no drainage. You could solve this with some type of drainage pipe that allows the moisture to drain from your raised bed some distance from the bed, far enough so that a runner of bermuda will not invade the pipe. Of course the pipe will have to be sealed where it exists the barrier as well. When dealing with this type of system the constant rinsing of your soil by the irrigation/drainage action will have a tendency to leach out nutrients over time. Keep this in mind so as you amend your soil to a nice rich nutrient based growing medium suitable to the type of plants you are growing you are able to replace leached out nutrients. As with all gardening (and everything else in life) there will be a long period of trial and error. Good luck!

EM•1® Microbial Inoculant can be used to accelerate the soil building process and promote beneficial microbial communities. The soil building process revolves around soil aggregate formation. Soil aggregates form as mineral and decomposed organic matter particles are bound together by microbial secretions that act as glues. Stable and well-formed soil aggregate is the key to overall soil function. EM•1® produces high levels of polysaccharides and other beneficial enzymes and organic acids that help build stable aggregate and soil structure. Increased aggregate stability prevents the pore spaces between the aggregates from collapsing during heavy, saturating rains and reduces compaction caused by machinery. Furthermore, improved soil aggregate stability reduces soil erosion and run-off. Soils are better able to absorb and retain moisture, as well as cycle nutrients.
Many nutrients are held in the top layers of soil due to the cation exchange capacity (CEC). The CEC increases as aggregate formation mature because the aggregate are providing the surface area for the nutrients to adsorb or stick to (not absorb). EM•1® efficiently breaks down organic matter into stable humus, a key component to aggregate formation, by reducing oxidative forces that primarily rob the soil of Carbon and Nitrogen in the form of methane and ammonium gases, respectively. This is achieved from a reduction of available Hydrogen ions due to a favorable change of organic acid composition and concentration in the soil. The result is that a greater amount of organic matter is converted to humus, aiding in aggregate formation.

Nitrate is an anion (not involved in CEC), and is prone to leach into the sub-soil if not readily used, and becomes part of amino acid chains. Amino acids are not negatively charged and can be utilized as plant food over a long period of time. EM•1® helps to improve Nitrogen cycling at two points. First, when EM•1® creates a reducing environment as raw organic nitrogen is decomposed eventually into nitrate ,reducing the amount of mineralization of Nitrogen and Carbon. Second, when forming amino acids that provide a slow release food source for plants.

Added Benefits:
The benefits of EM•1® Microbial Inoculant are not just limited to direct soil applications. The foundation of a healthy plant is healthy soil. Crop quality standards can be strict and EM•1® foliar applications can be an important technique to improve crop quality and consistency. EM•1® foliar treatments help build leaf, stem, fruit, and flower tissue. Airborne diseases spread from plant to plant by wind, rain, and insects. EM•1® can significantly improve the plant's ability to fend off these disease vectors by reducing the space and moisture available to the pathogens on the plant surface. Improved crop sizing, consistency, post-harvest shelf life, color, flavor, and density are all benefits of foliar treatments. Results will vary depending on the crop. Spraying crops with EM•1® Microbial Inoculant on a regular basis will improve overall crop quality during harvest and maintain quality during storage and pack-out.

The use of EM•1® to improve soil structure, organic matter management, and nutrient cycling compliments efforts to reduce reliance on mechanical and material inputs. Establishing EM•1® Microbial Inoculant in soil ultimately results in increased profitability and sustainability.

***Note to first time users: It is important to apply EM•1® Microbial Inoculant consistently the first year to establish the cultures in soils. Once EM•1® is thoroughly established it works with reduced dependency.***

Fruits and veggies grown with EM•1® are sweeter and have been tested to have higher vitamin counts than conventionally grown fruits and veggies.

If you would like to try some fruit growth with EM•1® Microbial Inoculant, Whole Foods Market exclusively carries sustainably-grown bananas from EARTH University in Costa Rica. These bananas are grown with EM•1® Microbial Inoculant and EM•1® Bokashi. Whole Foods Markets now also carries banana paper products made with EM•1® as well. These are available across the country.

Forgiveness please!..... I only wish to profit by helping to create a sustainable world. The EM in the post is from the original company(non-profit) and I have no ties . My EM comes from SCDWORLD.NET .........EM has helped the world and I just think that you might want to learn more on This Earth Saving Revolution. EM AMERICA.COM (not a dime goes to EM of California) I get paid by the many prayers of those that follow the EM trail . EM of California is a small family run EM Retail shop in the Napa Valley.