Abstract Boston fern [ Nephrolepis exaltata (L.) Schott ‘Rooseveltii’] was grown with sufficient and insufficient levels of N and K and leaf nutrient concentrations were determined periodically from 4 frond sections: frond tips, 10–12 cm; frond midsections, 10–12 cm; frond bases, 10–12 cm; and whole fronds, 30–40 cm. Both the frond midsection and the whole frond were found to be acceptable for foliar analysis. Frond tips had the lowest nutrient concentrations for most elements. Foliar N was similar for all frond sections sampled. Nitrogen deficiency symptoms occurred after 2 to 4 weeks of minus N conditions. When three N sources were added to plants grown under minus N conditions, N source had a limited influence on N uptake as measured by foliar analysis. One and 2 weeks after N treatment was restored to N-deficient ferns, foliar N had increased 55 and 100%, respectively.