Table 1. Soil C10–C50 and PAH concentrations at the beginning (October 2011) and at the end (April 2012) of the greenhouse experiment.

	C10–C50			PAH
	October 2011 (mg kg−1)	April 2012 (mg kg−1)	% Degraded	October 2011 (mg kg−1)	April 2012 (mg kg−1)	% Degraded
NC-NP	0.00±0.00	0.00±0.00	NA	0.00±0.00	0.00±0.00	NA
NC-P	18.33±44.91	0.00±0.00	NA	0.00±0.00	0.00±0.00	NA
C-NP	1,546±635	438±104	62.0±35.5	59.6±31.6	8.3±4.1	85.1±4.7
C-P	912±402	447±167	45.6±23.2	60.3±37.8	8.7±5.9	82.9±10.7

Abbreviations: C-NP, contaminated, not planted; C-P, contaminated, planted; NA, not applicable; NC-NP, not contaminated, not planted; NC-P, not contaminated, planted; PAH, polycyclic aromatic hydrocarbons.

The % degradation was calculated separately for each of the pots.

Values are average±s.d. (N=6 for all except C-NP, where N=5 after removal of one outlier (pot 62; Supplementary Table S1)).