How did colonel Lloyd keep the slaves boys from taking his fruits

Colonel LLoyd put up a fence and covered it in tar. Thus, he had evidence of the trespassers who stole his fruit. Once caught, the fruit thieves were beaten severely.

"Scarcely a day passed, during the summer, but that some slave had to take the lash for stealing fruit. The colonel had to resort to all kinds of stratagems to keep his slaves out of the garden. The last and most successful one was that of tarring his fence all around; after which, if a slave was caught with any tar upon his person, it was deemed sufficient proof that he had either been into the garden, or had tried to get in. In either case, he was severely whipped by the chief gardener."