Phenology: Growth and Flowering Times

Observations have been made at Pleasant Valley Conservancy of the growth, flowering, and seed set for many plant species. The table below gives the averages for 126 species for a four-year period. Included in this table are prairie, savanna, and woodland species. Weeds and nonnative species are not included.

The plants are arranged in this table by the time of first flowering, since this is the time when each species is most readily visible. The species listed are only those that are present at Pleasant Valley Conservancy, but this list includes most of the common prairie, savanna, and woodland species to be found at other locations in southern Wisconsin.

Phenology of the vegetative state Although the species are arranged by time of first flowering, data are also given on the times when the plants were first observed in the vegetative state. The column "1st leaves" gives dates when the first recognizable leaves have been seen. These dates are very useful because they give early seasonal clues to the success of restoration work. However, not all species are easily recognized in the vegetative state. The leaves of some species are not very distinctive, so that a positive identification is not possible. To recognize a plant in the vegetative state, it helps a lot to know where it is likely to grow, and when. The leaves of some plants (prairie dock and compass plant) are so characteristic that a positive identification is easy. For others, considerable field experience is necessary. When in doubt, mark the plant and return when it is in flower.

Phenology of flower bud formation Although the species are arranged by time of first flowering, many species can be recognized much earlier because of their distinctive flower buds. The column giving these dates may thus be helpful.

Phenology of flowering Flowering times vary from year to year, and also from site to site. Thus, the times in this table are only approximate. Some species flower over only a very short duration, whereas others flower over a much longer period of the growing season. No single specimen of a species will flower for a long time, but different specimens, either in the same location or at different locations, may flower early while others flower late. Examples of species that flower over a long period of time are black-eyed susan and ox-eye sunflower.

Phenology of seed set Some species set ripe seed soon after they are finished flowering, whereas seeds of others take much longer to ripen. Some species hold their seeds for long periods of time, so that seed collecting is easy, whereas other species drop their seeds soon after they are ripe. The data in the table give a rough approximation of the phenology of seed set. Also given are approximate dates when ripe seed can be collected. Follow this link for more extensive data on seed collecting dates. Those species whose seeds are held in pods are listed in the Comments column. Since the seeds are ripening inside pods, it is difficult to determine when they are ready to collect. The collecting dates given in the table are only approximate but may be helpful. Also given are the last dates at which seeds can be collected. Again, these dates are only approximate.

Flowering times: Sorted by date of first flowers

Latin name Common name 1st leaves Fl buds 1st fl Last fl 1st seeds 1st collect seeds Last collect seeds Comments
Ranunculus fascicularis Early buttercup     24-Mar 23-May   7-Jun    
Caltha palustris Marsh marigold   8-Apr 11-Apr 19-May 19-May      
Oxalis violacea Violet wood-sorrel     14-Apr 2-Jun   7-Jun    
Viola pedata Bird's foot violet     14-Apr 20-May 23-May 31-May 15-Jun  
Viola soraria Door-yard violet     14-Apr 27-May        
Antennaria neglecta Field pussytoes 10-Apr 12-Apr 15-Apr 13-May   24-May 10-Jun  
Anemone quinquefolia Wood anemone   14-Apr 17-Apr 22-May        
Aquilegia canadensis Wild columbine 31-Mar 17-Apr 20-Apr 17-Jun 15-Jun 30-Jun 15-Jul  
Ranunculus abortivus Small-flowered buttercup 19-Apr   22-Apr 27-May   15-Jun    
Lithospermum incisum Fringed puccoon     25-Apr 5-Jun 25-Jun 10-Jul 25-Jul  
Sisyrinchium campestre Blue-eyed grass   17-Apr 25-Apr 27-May 10-Jun 20-Jun 29-Jun  
Polemonium reptans Jacob's ladder 11-Apr 27-Apr 28-Apr 22-May 10-Jun 25-Jun 7-Jul  
Viola pedatifida Prairie violet     29-Apr 27-May        
Zizia aurea Golden Alexander   8-Apr 29-Apr 7-Jun 5-Aug 26-Aug 15-Sep  
Dodecatheon meadia Shooting star 31-Mar 30-Apr 6-May 3-Jun 15-Jul 5-Aug 15-Aug  
Geranium maculatum Wild geranium 10-Apr 29-Apr 6-May 10-Jun 15-Jun 30-Jun    
Polygonatum biflorum Smooth Solomon's seal 19-Apr 6-May 6-May 31-May 15-Aug 29-Aug 10-Oct  
Trillium grandiflorum Large-flowered trillium   1-May 7-May 26-May        
Heuchera richardsonii Prairie alum-root 16-Apr 6-May 9-May   15-Jun 30-Jun    
Saxifraga pensylvanica Swamp saxifrage 11-Apr 6-May 10-May 6-Jun 17-Jun 23-Jun    
Lithospermum canescens Hoary puccoon     11-May 12-Jun   5-Aug    
Podophyllum peltatum May-apple 12-Apr 9-May 11-May          
Actaea rubra Red baneberry 19-Apr 27-Apr 12-May 31-May 5-Jul 20-Jul 7-Aug  
Lupinus perennis Wild lupine 19-Apr 9-May 12-May 7-Jun 15-Jun 25-Jun    
Cypripedium calceolus pubescens Large yellow lady-slipper 14-Apr 11-May 13-May 12-Jun   15-Oct    
Senecio pauperculus Balsam ragwort 9-May   13-May 18-Jun        
Osmorhiza longistylis Smooth sweet cicely 13-Apr   16-May 13-Jun 15-Jul 7-Aug 28-Aug  
Lysimachia quadrifolia Whorled loosestrife 3-Apr   18-May 8-Sep 10-Sep 25-Sep    
Smilacina racemosa False Solomon's seal 13-May 17-May 19-May 10-Jun 15-Aug 10-Sep 15-Oct  
Anemone canadensis Meadow anemone 20-Apr   22-May 17-Jun 8-Aug 15-Aug    
Taenidia integerrima Yellow pimpernel 19-Apr 15-May 22-May 10-Jun 23-Jul 6-Aug 15-Aug  
Triosteum perfoliatum Tinker's weed 14-Apr 11-May 23-May 1-Aug 16-Sep 10-Oct 26-Oct  
Tradescantia ohiensis Common spiderwort 26-Apr 20-May 27-May 9-Jul 2-Jul 15-Jul 30-Jul  
Anemone cylindrica Thimbleweed   24-May 31-May 24-Jun 25-Aug 15-Sep 5-Oct  
Campanula rotundifolia Harebell 23-May   5-Jun 16-Oct 15-Aug 5-Sep 20-Sep  
Angelica atropurpurea Great angelica 11-Apr 22-May 6-Jun 14-Jun 5-Jul 13-Jul 20-Jul  
Asclepias exaltata Poke milkweed   22-May 7-Jun 22-Jun 29-Jun 30-Sep 21-Oct Pods visible long before seeds ready to collect
Lobelia spicata Pale spiked lobelia     7-Jun 8-Jul 10-Jul 25-Jul 7-Aug  
Penstemon digitalis Penstemon   20-May 7-Jun 25-Jun 6-Jul 5-Oct    
Bromus kalmii Prairie brome     9-Jun 23-Jul 23-Jul 15-Aug 8-Sep  
Thalictrum dasycarpum Purple meadow-rue 12-Apr 16-May 9-Jun 23-Jun 5-Aug 14-Aug 15-Sep  
Echinacea pallida Pale purple coneflower 17-May 7-Jun 10-Jun 3-Aug 24-Aug 13-Sep 5-Oct  
Heliopsis helianthoides Ox-eye sunflower 9-May 10-Jun 12-Jun 21-Sep 7-Oct      
Asclepias purpurascens Purple milkweed 13-May 19-May 13-Jun 9-Jul 15-Aug 17-Sep 16-Oct Pods visible long before seeds ready to collect
Baptisia lactea White wild indigo 2-Jun 7-Jun 13-Jun 2-Jul 15-Aug 5-Sep 10-Sep Pods
Euphorbia corollata Flowering spurge 7-Jun 13-Jun 14-Jun 26-Aug 30-Aug 13-Sep 20-Sep  
Parthenium integrifolium Wild quinine     14-Jun 12-Sep 25-Aug 15-Sep 10-Oct  
Amorpha canescens Lead-plant 16-May 3-Jun 15-Jun 5-Aug 26-Aug 15-Sep 1-Oct  
Asclepias tuberosa Butterfly weed   8-Jun 16-Jun 5-Aug 25-Sep 2-Oct 15-Oct Pods visible long before seeds ready to collect
Coreopsis palmata Prairie tickseed 4-May 13-Jun 20-Jun 19-Jul 30-Sep 15-Oct 30-Oct  
Potentilla arguta Prairie cinquefoil 20-May 2-Jun 20-Jun 28-Jul 15-Aug 15-Sep 5-Oct  
Rudbeckia hirta Black-eyed Susan 19-May 14-Jun 20-Jun 8-Sep 13-Sep 14-Sep 23-Oct  
Solidago missouriensis Missouri goldenrod   7-Jun 20-Jun 16-Aug 5-Oct 15-Oct 30-Oct  
Silphium perfoliatum Cup plant 28-Apr   21-Jun 8-Sep 30-Aug 13-Sep 30-Sep  
Elymus hystrix Bottlebrush grass 19-Apr 20-Jun 22-Jun 30-Jul 5-Aug 15-Aug 29-Aug  
Lilium michiganense Turk's cap lily 12-Apr   22-Jun 18-Jul   20-Sep 15-Oct pods
Lysimachia ciliata Fringed loosestrife 21-Apr   27-Jun 20-Jul 10-Sep 25-Sep    
Asclepias incarnata Swamp milkweed 20-Jun   28-Jun 11-Aug 14-Aug 16-Sep 15-Oct Pods visible long before seeds ready to collect
Ceanothus americanus New Jersey tea 29-Apr 3-Jun 28-Jun 14-Aug 15-Sep 30-Sep 5-Oct  
Desmodium canadense Showy tick-trefoil 15-Jun 22-Jun 28-Jun 30-Jul 6-Aug 26-Aug 14-Sep  
Eryngium yuccifolium Rattlesnake master 1-May 14-Jun 28-Jun 16-Aug 15-Sep 10-Oct    
Monarda fistulosa Wild bergamot 16-Apr 21-Jun 28-Jun 22-Aug 26-Aug 15-Sep 25-Sep  
Ratibida pinnata Yellow coneflower 19-Apr 14-Jun 29-Jun 20-Aug 10-Sep 10-Oct 27-Oct  
Verbena stricta Hoary vervain   24-Jun 29-Jun 21-Aug 26-Aug 15-Sep 10-Oct  
Dalea candida White prairie clover   15-Jun 2-Jul 30-Jul 25-Aug 15-Sep 30-Sep  
Astragalus canadensis Canadian milkvetch 17-Apr 27-Jun 3-Jul 5-Aug 14-Aug 15-Sep 5-Oct Pods
Desmodium illinoense Illinois tick-trefoil 8-Jun 24-Jun 3-Jul 28-Jul 22-Jul 14-Aug 22-Sep  
Napaea dioica Glade mallow 28-Apr 12-Jun 3-Jul 20-Jul 30-Jul 26-Aug 15-Sep  
Silphium laciniatum Compass plant 25-Apr 16-Jun 3-Jul 25-Aug 8-Sep 15-Sep 30-Sep  
Verbena hastata Blue vervain     5-Jul 8-Sep 25-Aug 15-Sep 30-Sep  
Campanula americana Tall bellflower 19-May 29-Jun 6-Jul 29-Aug 15-Sep 5-Oct 25-Oct  
Dalea purpureum Purple prairie clover 15-Jun 29-Jun 6-Jul 16-Sep 25-Aug 15-Sep 30-Sep  
Solidago juncea Early goldenrod   24-Jun 8-Jul 2-Sep 5-Oct 15-Oct 30-Oct  
Bouteloua curtipendula Side oats grama 1-Jul   9-Jul 26-Aug 15-Aug 30-Aug 3-Nov  
Hypericum pyramidatum Great St. John's wort 31-May 6-Jul 10-Jul 1-Aug 10-Sep 30-Sep 15-Oct  
Silphium terebinthinaceum Prairie dock 29-Apr 24-Jun 10-Jul 19-Aug 7-Sep 13-Sep 20-Sep  
Veronicastrum virginicum Culver's root 17-May 27-Jun 12-Jul 28-Aug 25-Aug 15-Sep 30-Sep  
Oenothera biennis Common evening-primrose 25-May   13-Jul 30-Sep 15-Aug 15-Sep 15-Oct  
Arnoglossum atriplicifolia Pale Indian plantain 14-Apr 29-Jun 14-Jul 10-Sep 16-Sep 25-Sep 4-Oct  
Asclepias verticillata Whorled milkweed 14-Jun 27-Jun 14-Jul 6-Aug 19-Aug 15-Sep 30-Sep Pods visible long before seeds ready to collect
Silphium integrifolium Rosinweed 9-May 1-Jul 14-Jul 26-Aug 8-Sep 27-Sep 14-Oct  
Vernonia fasciculata Common ironweed 17-May 21-Jun 14-Jul 25-Aug 25-Sep 10-Oct 15-Oct  
Eupatorium purpureum Purple joe-pye weed 16-May 15-Jun 18-Jul 23-Aug 5-Sep 15-Sep 25-Sep  
Pycnanthemum virginianum Common mountain mint 15-Jun 6-Jul 18-Jul 26-Aug 10-Sep 11-Oct 25-Oct  
Eupatorium maculatum Spotted joe-pye weed 19-May 21-Jun 19-Jul 5-Sep 8-Sep 25-Sep 5-Oct  
Liatris pycnostachya Prairie blazing star   29-Jun 19-Jul 15-Aug 20-Sep 5-Oct 15-Oct  
Helianthus divaricatus Woodland sunflower 20-May 2-Jul 23-Jul 2-Sep        
Sporobolus heterolepis Prairie dropseed 1-May   23-Jul 31-Aug 25-Aug 15-Sep 30-Sep  
Agastache nepetoides Yellow giant hyssop 20-Apr 6-Jul 25-Jul 30-Aug 25-Sep 5-Oct 25-Oct  
Andropogon gerardii Big bluestem 1-Jul 15-Jul 25-Jul 2-Sep 20-Sep 5-Oct 20-Oct  
Pedicularis lanceolata Lousewort 17-May 9-Jul 25-Jul 12-Sep 25-Sep 5-Oct 15-Oct  
Aureolaria grandiflora Yellow false foxglove 16-Apr 11-Jul 26-Jul 21-Aug 25-Sep 15-Oct 30-Oct Pods
Cirsium discolor Pasture thistle 20-May 19-Jul 26-Jul 2-Sep 12-Sep 20-Sep 30-Sep  
Allium cernuum Nodding wild onion     27-Jul 22-Aug 2-Sep 15-Sep    
Eupatorium perfoliatum Common boneset 31-May 30-Jun 27-Jul 13-Sep 15-Sep 30-Sep 10-Oct  
Eupatorium sessilifolium Upland boneset 25-Apr 20-Jun 29-Jul 2-Sep 25-Sep 7-Oct 20-Oct  
Sorghastrum nutans Indian grass 1-May   30-Jul 16-Sep 21-Sep 7-Oct 30-Oct  
Lobelia siphilitica Great blue lobelia   27-Jul 3-Aug 26-Sep 3-Jul 5-Oct 15-Oct  
Aster sagittifolius Arrow-leaved aster 14-Apr   5-Aug 5-Oct   15-Oct 30-Oct  
Kuhnia eupatorioides False boneset 19-May 5-Jul 5-Aug 2-Sep 5-Sep 13-Sep 30-Sep  
Lespedeza capitata Round-headed bush clover 7-Jun 13-Jun 5-Aug 28-Aug 15-Sep 10-Oct 21-Oct  
Rudbeckia triloba Brown-eyed Susan 10-Jun 1-Aug 5-Aug 16-Sep 5-Oct 15-Oct 30-Oct  
Solidago ulmifolia Elm-leaved goldenrod   7-Jul 5-Aug 15-Sep 5-Oct 20-Oct 5-Nov  
Eupatorium altissimum Tall boneset 19-May 1-Jul 6-Aug 15-Sep 26-Sep 11-Oct 26-Oct  
Rudbeckia laciniata Cut-leaved coneflower 22-May 18-Jul 9-Aug 5-Sep        
Cirsium muticum Swamp thistle 19-May 18-Jul 11-Aug 8-Sep 25-Aug 16-Sep    
Hasteola suaveolens Sweet Indian plantain 17-Apr 11-Jul 11-Aug 10-Sep 25-Sep 30-Sep 7-Oct  
Ambrosia artemisiifolia Common ragweed 26-Jun   14-Aug 2-Sep        
Aster novae-angliae New England aster     14-Aug 5-Oct   15-Oct 30-Oct  
Liatris aspera Rough blazing star 18-Jun 6-Jul 14-Aug 16-Sep 20-Sep 5-Oct 15-Oct  
Schizachyrium scoparium Little bluestem 5-Jun 26-Jul 14-Aug 16-Sep 22-Sep 12-Oct 4-Nov  
Aster laevis Smooth blue aster 1-Jun 26-Jul 15-Aug 5-Oct 6-Oct 25-Oct 5-Nov  
Gentiana andrewsii Bottle gentian 15-Jun 26-Jul 15-Aug 20-Sep 25-Sep 15-Oct 30-Oct  
Solidago rigida Stiff goldenrod 19-Apr 3-Jul 15-Aug 15-Sep 25-Sep 5-Oct 24-Oct  
Solidago speciosa Showy goldenrod 17-May 5-Aug 20-Aug 26-Sep 6-Oct 21-Oct 7-Nov  
Solidago nemoralis Gray goldenrod   3-Aug 21-Aug 21-Oct 15-Oct 24-Oct 5-Nov  
Gentiana alba Cream gentian 4-May 14-Aug 23-Aug 13-Sep   25-Oct 5-Nov  
Solidago flexicaulis Zig-zag goldenrod 21-Apr 15-Aug 23-Aug 26-Sep 24-Oct 30-Oct 5-Nov  
Chelone glabra Turtlehead 22-Jun 19-Aug 26-Aug 5-Sep 25-Sep 11-Oct 25-Oct  
Gentianella quinquefolia Stiff gentian 3-Jun 20-Aug 26-Aug 21-Sep 5-Oct 15-Oct 30-Oct  
Helenium autumnale Sneezeweed 22-Jun 21-Aug 26-Aug 2-Oct 25-Sep 10-Oct 21-Oct  
Aster lateriflorus Calico aster 1-Jul 23-Aug 30-Aug 5-Oct   25-Oct 5-Nov  
Prenanthes alba Lion's foot 21-Apr 19-Aug 8-Sep 17-Sep 30-Sep 10-Oct 21-Oct  
Aster ericoides Heath aster 6-Jul   11-Sep 26-Oct   30-Oct 5-Nov  
Aster oolentangiensis Sky-blue aster 17-May 27-Aug 20-Sep 10-Oct   15-Oct 30-Oct  
Helianthus pauciflorus Prairie sunflower 27-Jul 9-Aug 27-Sep   20-Sep 4-Oct