ANOVA analyses for days to emergence, absolute growth rate (AGR; eq. 2), total seedling dry mass and taproot length.

Days to emergence was analysed for within-pot averages (4 seeds pot−1). AGR, total mass and taproot length were evaluated on the first seedling to emerge per pot. Watering treatments were pulse duration (number of days at start of experiment with 10 mm water per day) and follow-up watering frequency (post-pulse frequency of 5 mm watering events). Seedlings of P. velutina (n = 96) and A. greggii (n = 91) were thinned as needed to one per pot and harvested 16 and 17 days after imbibition was initiated.