Last year I began establishing three raised beds of fruit trees interplanted with vegetables, herbs, and short term fruits like Banana and Papaya. The trees were planted on beds topped off with compost and well mulched.
This is what it looked like at first:
Later, I planted single stalks of lemongrass down each side of the beds at 1 foot (30 cm)spacing. During the first few months I grew watermelon, cowpeas, pumpkin and sweet potatoes in the sandy soil between each bed. Later, I mulched the pathways between each bed with chipped wood mulch obtained from a hurricane debris shredding operation.
The intent was to serve 3 purposes:
1. Produce a permanent source of mulch for each bed adjacent to where it would be used.
2. Stabilize the sides of the raised beds to prevent slippage of mulch down the sides.
3. Use the grass to produce some shade and a low windbreak over the beds.
4. Occupy the space alongside each bed to prevent other weedy plants from becoming established.
Here are two views of how it looked once the grass became established:
Last week after one year's growth I cut all the lemongrass and placed it across the beds. It made a very good mulch coverage and began regrowing immediately. I may be able to cut it once again this summer if needed. I believe that rather than 1 foot spacing an 18"(20 cm) spacing would be close enough. The particular clone of lemongrass used is common but I have built up a stock of a different sort which grows much taller and does set viable seed during our wintertime, I'll be testing that one out later this year.