Gardner's Inivisible Gardener Thought Experiment

The late skeptical intellect Martin Gardner once posed this conundrum: one that, being a Christian, I ponder from time to time. 
Essentially: "We find a lovely, organized garden in the woods.  We can't see the gardener nor observe him in action. We employ every sensor, test, and alarm possible, and we still can't detect him. We can't see any action like weeds being pulling out of the ground by a visible or invisible force. How is such an insubstantial gardener different from no gardener at all?" 
Gardner's preferred conclusion that there was no gardener, however, is based on the preconception that we should be able, in some way, to catch the gardener at work.  There are actually two possible solutions:
1) a gardener who is so different from us no test can spot him or directly observe his work and
2) No gardener at all.
Possibility 1 is one we cannot test, but neither can we say as a fact that there is no such gardener. Possibility 2 is unsatisfying because we have not solved the problem: we still have to come up with an explanation for the garden, one that does not require a gardener.  A) Maybe we can.  B) Maybe there is one, but our science is not yet advanced enough to find it (possible but unprovable).  C) Maybe we can't find it at all.  In cases B or C we are still at a loss - we still have to explain the garden. 
Martin's thought experiment is certainly thought-provoking. But the answer to it is not as simple as be believed.