The trace fossil Zoophycos has long been considered an archetypical example of a deposit-feeding trace. The important discovery that at least some types of Zoophycos actively introduce surface material into the burrow sparked a new interest in alternative ethological explanations. Recently proposed ethological explanations for the trace fossil Zoophycos include gardening of microorganisms. In the gardening model, organic-rich material is collected on the sediment surface and introduced into the burrow as substrate for the cultivation of microorganisms. Because microorganisms are known to fractionate strongly against ¹³C, especially under low oxic to anoxic conditions, it is argued that any gardening activity in the trace would result in a noticeable shift in δ¹³C between spreiten and adjacent host sediment. In order to test this hypothesis, δ¹³C_org of spreiten material and directly adjacent host material was measured in 12 host-spreite couples from three cores from the eastern North Atlantic. The results show δ¹³C_org values ranging from -23.6‰ to -21.6‰ for host sediment and between -23.4‰ and -21.8‰ for Zoophycos material. The difference in the couples is usually only a few tenths of a permil. The minimal difference between Zoophycos and host material suggests that gardening plays an insignificant role. However, the trace material generally displays a significant enrichment in organic carbon compared to surrounding host sediment. Therefore, the gardening hypothesis is rejected in favor of a cache model, where food is squirreled away for poorer times.