They say that if you follow your bliss, the money will follow. I am not rich yet, but I am stress free in my work, and that is more valuable to me. The Xeriscape style of landscaping is where I want to work. The only aspect of this style I don't do is the grass. I ask the customer to have the lawn maintenance done separately, simply because I do not wish to return week after week to mow.
Most of my projects are residential and I care for them monthly, others I do twice a month, and a few on a quarterly schedule. Visiting a project monthly is perfect to maintain a Xeriscape landscape. Feeding, pruning, clean-up, weed control, irrigation system checks, and vegetable gardens can be cared for with these twelve visits per year. Some places need a little assistance from the owner: spraying weeds for instance but for most of the year I manage well.
So to maintain a project means to keep the status quo. I bid my projects based on maintenance and anything over that would be on extra change. For example, planting, removals, staking, irrigation changes, pest control, and animals.
This I hope will help you decide whom you wish to have taking care of your garden.