Phenology Report for April 14, 2015

From time to time, we will be reporting on the development of invasive plants across Illinois, informing readers about what is in bloom, leafing out, setting seed, senescing in different regions of the state.  Feel free to add to the knowledge by emailing chris.evans@illinois.gov and letting me know what the plants are doing in your area of Illinois.

Phenology Report for April 14, 2015*

(Contributors include Cathy McGlynn, Mike Daab, Caleb Grantham, Nick Seaton, and Eric Smith, )
*Report based upon observations between April 8-14, 2015

Southern Illinois

• Multiflora rose, Rosa multiflora and bush honeysuckle, Lonicera maackii  - These two common woody shrub species are actively expanding their leaves right now and are nearing full leaf expansion.  This is not the time of year to treat these species with chemicals.  Wait until the leaves have fully expanded before conducting cut stump or foliar applications.
• Autumn olive, Elaeagnus umbellata - This species is actively expanding its leaves and starting to flower. This is not the time of year to treat this species with chemicals.  Wait until the leaves have fully expanded before conducting cut stump or foliar applications.
• Callery (Bradford) pear, Pyrus calleryana - This species is past peak for flowering.  Many of the plants still have flowers on them but the leaves are expanding now as the flowers fade.  It is still a great time of year to find and report new populations.  Look for this species along roadsides, rights-of-way, and other open habitats.
• Garlic mustard, Alliaria petiolata - Garlic mustard is bolting right now and starting to bloom. If a population is bolting but not flowering, it can still be treated with herbicide.  Once the population starts flowering heavily, you best option is to hand pull, bag, and remove the plants.
• Italian arum, Arum italicum - Is starting to actively grow.  New succulent leaves can be found.  This new invader is showing up in land within and adjacent to urban areas.

Central Illinois

• Bush honeysuckle, Lonicera maackii; autumn olive, Elaeagnus umbellata; and Japanese honeysuckle, Lonicera japonica - These woody species are starting to leaf out, moving towards mid-leaf expansion.  This is not the time of year to treat these species with chemicals.  Wait until the leaves have fully expanded before conducting cut stump or foliar applications.
• Callery (Bradford) pear, Pyrus calleryana - This species is beginning to flower now.  This is the perfect time of year to survey and find new populations of this plant.  Look for this species along roadsides, rights-of-way, and other open habitats.
• Garlic mustard, Alliaria petiolata - Garlic mustard is not yet starting to bolt in Central Illinois but is expected to soon.  These populations can be treated with herbicides or hand-pulled.  Once the populations start to flower heavily, then hand pull, bag, and remove the plants.

Northern Illinois

• Lesser celandine, Ranunculus ficaria - This new invader is starting to bloom.  The bright yellow flowers blooming in low woods are easily spotted this time of year.  Be sure to verify identification, as there are native wildflowers that bloom in early spring that could be confused with this species.
• Japanese barberry, Berberis thungbergii and goutweed, Aegopodium podagraria - These two invaders are actively expanding their leaves right now.