Monarch Watch Blog

Milkweed and Nectar Plant Phenology Project

Friday, February 29th, 2008 at 9:07 pm by Jim
Filed under Phenology | 12 Comments »

Coming soon to a website near you – a new project to record the phenology of milkweeds and nectar plants used by monarchs. Phenology is the term given to the study of the seasonal progression of natural events involving plants and animals. In this case, we are interested in recording a series of “firsts” (first emergence of shoots, first flower bud, etc.). This study is needed to monitor the effects of proximate seasonal conditions and long-term effects of climate change on the plants on which monarchs depend.

These kinds of data are also needed to help us sort out the impacts of human-induced (anthropogenic) changes in the environment and those due to weather and climate. In short, we need to develop a more comprehensive understanding of the changing availability of the host and nectar plant resources utilized by monarchs. We will monitor 6 species of milkweeds and 10 nectar plants. Our goal is to create maps with isoclines that show the progressive greening up of the resources used by monarchs. For this to be a successful project, one in which we can make comparisons of one year with another, we will need hundreds of you to contribute your “firsts” from all over the country. We hope you will participate. If you have a Monarch Waystation, this project is another good way to put it to use for monarchs.

This project is a collaborative effort and we anticipate that it will be fully online in mid March or perhaps a bit later. Just before the website becomes fully operational, we will outline the program in greater detail and will provide additional justification and instructions for this program. The growing season for milkweeds and nectar plants is about to start in the south and it may have already started in some areas. If you are in the south, please start keeping a record of dates now, as the data can be submitted later.

Additional announcements about this program will be posted in the coming weeks.

We will monitor the following growth (or phenophases) for milkweeds:

– Date of first emergence from soil – the first shoots to break soil
– Date of first flower bud (no matter how small)
– Date of first open flower or floret on a flower head
– Date of last flower on a flower head
– Date of first seed pod (marked by elongation of the ovary at the base of a flower)
– Date of first open seedpod

For the nectar plants we will only record the dates of first flowering.

The milkweed and nectar plant species have been selected on the basis of their broad distributions, their use as season markers (e.g., American plum) and their importance to monarchs. The links for each species will lead you to distribution maps, species accounts and images of the plants and the flowers.

Milkweed Species

Asclepias asperula – Spider milkweed [Distribution] [Images]

Asclepias incarnata – Swamp milkweed [Distribution] [Images]

Asclepias speciosa – Showy milkweed [Distribution] [Images]

Asclepias syriaca – Common milkweed [Distribution] [Images]

Asclepias tuberosa – Butterfly milkweed [Distribution] [Images]

Asclepias viridis – Green antelopehorn milkweed [Distribution] [Images]

We will monitor spring, summer and fall nectar plants.

Spring (April-May)

Syringa vulgaris – Common lilac [Distribution] [Images]

Taraxacum officinale – Common dandelion [Distribution] [Images]

Prunus americana – American plum [Distribution] [Images]

Summer (June-July)

Cephalanthus occidentalis – Common button bush [Distribution] [Images]

Echinacea purpurea – Eastern purple coneflower [Distribution] [Images]

Vernonia fasciculata – Prairie ironweed [Distribution] [Images]

Fall (August-October)

Helianthus annuus – Common sunflower [Distribution] [Images]

Oligoneuron rigidum (Solidago rigida) – Rigid goldenrod [Distribution] [Images]

Liatris aspera -Tall blazing star [Distribution] [Images]

Verbesina virginica – Frost weed [Distribution] [Images]

Symphyotrichum ericoides (Aster ericoides) – White heath aster [Distribution] [Images]

We hope you will participate in the phenology program outlined above. Observing plant growth and recording the data is quite easy – simply follow these steps:

1. Review the list of plants along with their pictures and distributions to determine which species occur in your area.

2. Create a journal (on paper and/or on your computer) listing the species you are most likely to observe.

3. Record the “firsts” for each species; e.g., first shoots, first flowers, first seed-pods, as appropriate, in your journal.

4. After you have accumulated a number of observations, visit the United States of America National Phenology Network (USA-NPN) website and record the data for each species. The USA-NPN website will have a separate section for the Monarch Watch plants by the 15th of May.

5. Be sure to make a note of the data that has been entered so as to avoid entering the same data at a later date.

This is a great project for classrooms, nature centers, families, and those interested in making additional uses of their Monarch Waystation habitats.

Revised 4-23-2008

  1. 12 Responses to “Milkweed and Nectar Plant Phenology Project”

  2. By Harlen E. Aschen on Mar 1, 2008

    I found Asclepias viridis and Asclepias oenotheroides with stems to at least six inches on Thursday, February, 28, 2008. Photos at: The viridis in the photo already had buds. This was about 5 miles west of Port Lavaca in Calhoun Co., along the midcoast of Texas. We have found both varieties this size in previous years as early as Feb. 14th when there weren’t freezes along the Texas coast. This is common and not exceptional, I was expecting to find one or both this past week. From past experience, we are figuring Asclepias asperula should be just sprouting now about sixty miles to the NW of us in DeWitt Co. … but this we have yet to document.

  3. By Pat Swerkstrom on Mar 3, 2008

    I will follow the phenology project with great interest. Although the information requested deals with plant growth, I would also like to receive any and all information regarding beneficial practices for monarch egg, larvae, and butterfly propagation—especially things we can do to limit predators and natural destructors in the wild. Thanks for any feedback in these areas.

  4. By Albert Eurs on Mar 3, 2008

    I have Tropical milkweed which has been growing and blooming throughout the year. It never goes dormant or dies back. I have six Asclepias fascicularis which do die back and they all sprouted about two weeks ago, around February 17th.

  5. By Deny Brooks on Mar 4, 2008

    I think Joe-Pye Weed, Black-eyed Susans, and Bergamont should be added to the summer Wildflower list

  6. By Harlen E. Aschen on Mar 4, 2008

    Altus and I found Asclepias asperula up and well on Sunday, March 2nd in DeWitt Co., Texas, even some A. oenotheroides, from sprouts to a plant with nine stems and buds.

  7. By Albert Eurs on Mar 27, 2008

    My Asclepias fascicularis have emerging buds.

  8. By B. Embry on Apr 24, 2008

    My Asclepias incarnata first popped through on April 14, 2008. Madison County Arkansas (NW corner of Ark.)Also spotted a few monarchs passing through April 12-20, 2008.

  9. By Mitchell Dormont on Apr 28, 2008

    I’m in New Jersey, Monmouth county, and noted that my Asclepias tuberosas had stems that were several inches out of the ground, yesterday, 4/27/08. My neighbor’s Lilac is in full bloom, though I do not know the variety. I had not been to the Monarch Watch site or blog for some time until noticing the 4/24 e-mail, today. I will participate in the phenology project.

  10. By Albert Eurs on Apr 30, 2008

    My Asclepias fascicularis are now blooming. The buds first opened on April 28th.

  11. By Dottie Carter on May 1, 2008

    I am so excited about the phenology project and will participate. My incarnata broke through the ground on April 9. The tuberosa have since emerged. I will be planting the curassavica this weekend (May 3 or 4) – it is only an annual here in Missouri but I plant it every year as it is so beautiful and the hummingbirds love it just as much as the monarchs. I am Waystation # 252……….

  12. By Mitchell Dormont on Jun 11, 2008

    Recent firsts are as follows:
    June,6th- the first Asclepias Tuberosa blossoms opened; June 9th-the first Coreopsis opened;June 10th-the first signs of purple showed up on Yarrow; June 11th- the first Monarda bloom opened, in a South facing planting, and the first Stella D’Oro daylilly bloomed.

  13. By Dr. Donna M. Laws on Sep 10, 2010

    My daughter found a caterpillar in my yard and gave it to my grandaughter who loves butterflies. We found supplies and made a home for it that contained everything the caterpillar needed. Mr. Butterfly (the name my grandaughter gave to the caterpillar) has structured his cocoon and we are waiting for the butterfly to emerge. These studies are very interesting and my grandaughter is going to do the study with 10 nectar plants to submit.
    Thanks for this information.
    Dr. Laws

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