Can I grow something between rows or on the edges of my olive tree orchard?

While we have seem some olive orchards with ornamentals such as roses or lavender on the edges, most olive orchards do not have crops between the trees. Paul Vossen of the University of California at Davis describes a study in his article on weed control which compared olive tree growth with different between the row soil treatments. The trees either had excellent weed control(wood chips made from mulched prunings), herbicide treated soil, clover "weed-cover crop" or annual grasses. The trees with clover grew at 1/2 the rate of the mulched trees, the ones with grass at 1/4 the rate of the mulched trees.

This would suggest that in between crops are a bad idea in general if your primary business is olives or olive oil. Some producers would argue with Paul though. McEvoy Ranch is totally organic and prides itself on its cover crops of clover and vetch between the trees. The cover crops and row end lavender support their bee hives and add another product to their retail line; lavender honey.