Due to unique physical and chemical properties, engineered nanomaterials (ENM) have been used in more than 2000 products that are commercialized in various sectors including electronics, therapeutics, medical diagnostics, clothing, and personal care products. Increasing use and unique properties of ENMs have raised concerns for their potential to cause harm to the receptor organisms. Soil contamination of ENMs may occur due to land application of biosolids and wastewater, land disposal of nanoproducts, surface runoff, and atmospheric deposition. Little is known about the potential impact of ENMs to the terrestrial crop plants. Therefore, we investigated the potential developmental phytotoxicity of silver and zinc oxide nanoparticles (NP) on two agriculturally significant crop plant species, Zea mays (maize) and Brassica oleracea var. capitata (cabbage), using microscopic examination of the root anatomy, germination rate and root elongation measurements. Results showed that the NPs evaluated were less toxic to germination and root growth than Ag+ or Zn+2 treatment. Several anatomical alterations were observed in the primary root cells in maize with both NPs and their corresponding ionic salt treatments. Greater biouptake of Ag occurred with Ag+ treatment than with the nanosilver treatment in maize. The number of metaxylem vessels was also altered with nanosilver, Ag+, and Zn+2 treatments, but not with nanozinc oxide treatment. These findings suggest that the NPs and their ions may impair the growth and development of the terrestrial crop plants. To understand whether uptake of nanosilver by maize is of human health concern would require a human health risk assessment considering exposure to nanosilver via human consumption of edible crops such as maize and cabbage.