Davey Tree Flipbooks

50 WILD PARSNIP (Pastinaca sativa) PLANT DESCRIPTION Wild parsnip, or yellow parsnip, is a broadleaf biennial weed that can be seen from late spring to early summer as an upright, single-stemmed, 3–5 foot tall branching plant with flat-topped yellow flowers. Wild parsnip can also be found as a seedling or rosette in spring and fall. Wild parsnip is easily noticed when flowering, especially in colonies along the road edge. LEAF: The leaves of young plants are oval shaped with tattered edges and look like parsley leaves. Leaves usually grow in groups of 5–11. As wild parsnip matures, branches develop and leaves grow larger and become more pointed with deeper lobes. STEM: Stems are hairless with prominent vertical ribs. FLOWER: Bright yellow flower heads bloom at the end of the branches and are arranged in an upright, flat-topped formation. SEED: Seeds are flat, green disks that eventually turn brown. The large fleshy tap root is another key identification feature that has a distinct parsnip or carrot smell when cut or crushed. REPRODUCTION: Seeds function as the primary means of reproduction. Most seeds drop around the parent plant but can be dispersed by wind, water, and animals. A mature wild parsnip plant is capable of producing thousands of seeds that remain viable in the soil for up to three years. WHY IT IS NOXIOUS: Use caution when handling wild parsnip leaves and stems, as contact with sap may cause a skin rash, especially when combined with sunlight exposure. SEASONAL IDENTIFICATION WHEN TO FIND: Wild parsnip is often seen in late spring to early summer as one of the only plants with yellow, upright, flat-topped flowers. SPRING IDENTIFICATION = EASY TO MODERATE Seedlings and rosettes can be found growing low among other plants and grass. Long stems with raised vertical ribs develop by late spring. SUMMER IDENTIFICATION = EASY Wild parsnip flowers in early summer and produces seed by midsummer. Leaves have become larger and more pointed with deeper lobes. The entire plant turns yellow and dies off by the end of the summer. FALL IDENTIFICATION = MODERATE Dead plants may still be standing as copper-brown stems. Look for remnant seed head and vertical ribs on stems. Young plants may be present in seedling or rosette form identified by leaf. WINTER IDENTIFICATION = MODERATE TO DIFFICULT Dormant seedlings and rosettes can be found in low-growing form. SIMILAR-LOOKING SPECIES GIANT HOGWEED (Hercleum mantegazzianum) leaves and form look similar from a distance. The flowers are upright and flat topped but they are white. The stems are covered in hairs. Giant hogweed is also much larger than wild parsnip. WILD CARROT (Daucus carota) flowers grow in a similar umbrella shape. The flowers are upright and flat topped, but they are white. Leaves are fern like. Stems do not branch and are covered in hairs. LOW HIGH ohio distribution roadside distribution growth seeds ability to dominate difficulty of control WHERE TO FIND: Wild parsnip is common in Ohio and can be easily found along the edge of the road in unmowed areas. It usually grows in patches. Wild parsnip favors well-drained soil and full sun, but tolerates shade and moderate soil moisture as well. CONTROL METHODS: MECHANICAL: Mow only from spring to early summer to maintain visibility and reduce seed production. Hand pull with gloves and use caution to avoid plant sap that can cause rashes. CHEMICAL: Make directed or broadcast applications from spring to early summer with selective herbicide. Make applications before flowers bloom. CULTURAL: Plant tall fescue in the fall and allow to grow tall in spring. RECOMMENDATION SUMMARY: Wild parsnip germinates in spring, lives for one full season, and overwinters as a rosette. In the second spring, the stems bolt, produce flowers, and then seeds before dying. Accomplishing control should not be difficult with many opportunities to prevent seed production. For best control results make herbicide applications in spring to early summer. Fall applications to rosettes and seedlings can also be effective. Use directed applications for large colonies and broadcast applications for sporadic wild parsnip growing in turf. Mow at flower emergence to reduce seed production. Plant tall fescue in early fall and allow to grow tall in spring to compete for space and to shade out seedlings. Failure to control wild parsnip will allow this tall-growing, moderately- competitive weed to form dense patches, thereby crowding out more manageable vegetation. biennial x 2 RIVM LEVEL OF CONCERN

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