TY - JOUR T1 - Improving nursery production of fifteen California native plant species: the effect of air-filled porosity JF - Native Plants Journal JO - NATIVE PLANTS JOURNAL SP - 249 LP - 258 DO - 10.3368/npj.16.3.249 VL - 16 IS - 3 AU - Juliet Braslow AU - Richard Evans Y1 - 2015/09/21 UR - http://npj.uwpress.org/content/16/3/249.abstract N2 - Many studies have shown the importance of air-filled porosity (VA) for optimal growth and dry weight of container-grown plants, but few have examined its effects on California native plants. Anecdotal evidence suggests that various upland native species require higher substrate aeration or less frequent irrigation than do standard nursery crops. We tested effects of VA and irrigation frequency on 15 California native species that had been identified by growers as challenging because of their aeration needs and sensitivity to overwatering. Plants were grown in substrates with 10% or 22% VA and were irrigated once (up to 574 ml) or twice daily (up to total of 972 ml). None of the applied treatments preferentially influenced plant survival or growth. Results indicate that these species may tolerate both normal and high VA values. The high survival and growth rates in these experiments indicate that growers’ experiences of plant death or poor plant growth are attributable to something other than VA. ER -