Red osier dogwood (Cornus stolonifera), blackberry (Rubus allegheniensis) and wild lupine (Lupinus perennis, in planted prairie) in flower, UWGB (Gary Fewless). Green Bay received 0.01 inches rain.

Saw my 1st nesting Painted Turtle of the year, Barkhausen, Brown County, WI (Steve Price).

Cleavers (Galium aparine) in flower, UWGB (Gary Fewless).

Silverweed (Argentina anserina, previously Potentilla anserina) in flower, Bay Beach Sanctuary. It has obviously been flowering for some time (Gary Fewless).

Spittle bugs (Order: Homoptera - Family: Cercopidae) observed on plants, UWGB (Gary Fewless).

A little rain today--0.40 inches in Green Bay.

Spreading Jacob's-ladder (Polemonium reptans), bald spike-rush (Eleocharis erythropoda) in flower, UWGB (Gary Fewless).

Heart-leaf twayblade (Listera cordata) in flower (probably not the first day).
Mosquitos are intense in many places (insect repellent or headnet are
required), Nicolet National Forest - Northern Oconto County, (Steve Janke).

It has been dry in the Green Bay area and the soil is becoming hard and is beginning to crack in a some places. We have had only 0.15 inches of rain in the last 15 days. This is a critical growth period for many plants that requires regular precipitation, and cannot be compensated by more rain later. Averages and totals are less relevant to the plants than regular availability (it is true for animals too--you can't compensate for 2 weeks without water by drinking 14 times as much on the 15th day).

Spring-cress (Cardamine bulbosa), in flower, UWGB (Gary Fewless).

Yesterday was about the end of the peak flowering season for Dandelions. Lesser numbers of flowers will occur throughout the summer and even well into the Fall, City of Green Bay (Gary Fewless).

Saw my first tiger swallowtail (Papilio glaucus)today. Also, first flowers observed on chokecherry (Prunus virginiana), and dame's rocket (Hesperis matronalis). First baby cottontail rabbit (Sylvilagus floridanus) observed, Town of Cooperstown, Manitowoc County (Joel Trick).

Horsechestnut (Aesculus hippocastanum) in flower, City of Green Bay (Gary Fewless) and at Silver Creek Park in City of Manitowoc (Jon Reisenbuechler).

May apple (Podophyllum peltatum), rose twisted-stalk (Streptopus roseus), and common wood sedge (Carex blanda) in flower, UWGB (Gary Fewless).

A few big white trillium Trillium grandiflorum turning pink; I still have not been bitten by a mosquito on UWGB's Cofrin Arboretum (though I have seen a few), UWGB (Gary Fewless).

First Tiger Swallowtail butterfly, Shawano County (Gary Fewless).

I may have missed the start, but today in Green Bay the carp were conspicuously spawning in very large numbers--a sight that never fails to amaze people when they first observe it (Gary Fewless).

Nodding trilliums (Trillium cernuum) and Red-berried Elder (Sambucus pubens) in flower, (5-25), Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler).

Shooting star (Dodecatheon media), Hill's oak (Quercus ellipsoidalis)and red oak (Quercus rubra) in flower, UWGB (Gary Fewless).

Choke cherry (Prunus virginiana) in flower, Allouez (Gary Fewless).

Japanese barberry (Berberis thunbergii), bastard-toadflax (Comandra umbellata) and hairy wood sedge (Carex hirtifolia) in flower, UWGB (Gary Fewless).

Quaking aspen (Populus tremuloides) dispersing seeds heavily. These trees began to flower (anthesis) 38 days ago on April 12, UWGB (Gary Fewless).

Tiger beetles (Cicindela sp., almost certainly C. sexguttata), the six-spotted tiger beetle, which loves woodland trails, Cofrin Arboretum Trail, UWGB (Mike Draney).

White spruce (Picea glauca) in flower (anthesis). Also in flower, and appearing to have been in flower for several days previously: American golden saxifrage (Chrysosplenium americanum) and brome-like sedge (Carex bromoides), Brown County (Gary Fewless).

My first mosquito bite of the year, Brown County (Gary Fewless). There are very few mosquitos so far, but the time is near when they will become numerous.

This is about the time of what I call "general greening of the trees" in the Green Bay area. Before this weekend the trees were beginning to develop leaves, but the forests were mostly open and you could see through them easily.  Now the forests  are becoming conspicuously green and more difficult to see through.   This is a very imprecise phenology item, but for what it's worth the average (by my estimation) has been May 7 over the last 18 years (Gary Fewelss).  Another vague phenology item of this period is the peak of dandelion  flowering Taraxacum officinale).

Wild geranium (Geranium maculatum) and downy hawthorn (Crataegus mollis) in flower, UWGB (Gary Fewless).

Blue cohosh (Caulophyllum thalictroides) in flower, but it has probably been in flower for several days, Brown County (Gary Fewless).

Sandbar willow (Salix exigua, previously S. interior) in flower (anthesis), UWGB (Gary Fewless).

First Green Frog of the year West Central Marinette Co, WI (Steve Price).

American Toads and Northern Leopard Frogs calling in full
chorus. Gray Treefrogs just starting in, Peshtigo Harbor Wildlife Area, Marinette Co, WI (Steve Price).

New flowering species today: false solomon's-seal (Smilacina stellata), fire cherry (Prunus pensylvanica), dwarf red raspberry (Rubus pubescens), sugar maple (Acer saccharum), early meadow rue (Thalictrum dioicum), red elderberry (Sambucus pubens), Missouri gooseberry (Ribes missouriense), false mermaid (Floerkea proserpinacoides), lily-of-the-valley (Convallaria majalis), henbit (Lamium amplexicaule), UWGB (Gary Fewless).

Wood thrush, Bairds Creek Parkway, Brown County (Steve Price).

The cool, cloudy weather has slowed the development of many plants, until today's sunny skies and warm temperatures. The following new flowering species were noted on UWGB today for the first time: Juneberry (Amelanchier sanguinea), American wild plum (Prunus americana), purslane speedwell (Veronica peregrina), thyme-leaved speedwell (Veronica serpyllifolia), corn speedwell (Veronica arvensis), big white trillium (Trillium grandiflorum), cherry currant (Ribes rubrum), Yellow violet (Viola pubesens). Jack-in-the-pulpit (Arisaema triphyllum) has flowers fully formed and the "spathe" is open, but the flowers are not yet in anthesis, UWGB (Gary Fewless).

American Toads "singing" at UWGB's Prairie Pond and Spring Azure butterflies flying (Gary Fewless).

First day of serious lawn mowing, City of Green Bay.

Many new avian arrivals for us today: Ruby-throated Hummingbird, Gray Catbird, Golden-winged Warbler, Blackburnian Warbler, Northern Parula, Least Flycatcher, Magnolia Warbler, Black and White Warbler, Bobolink, Chestnut-sided Warbler, Blue-headed Vireo, Veery, Swainson's Thrush.
Noted our first Wood Anemone (Anemone quinquefolia) and Yellow Trout Lilly (Erythronium americanum) in bloom. Scarlet Cup fungi were observed, Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler).

A significant movement of migrants today, with the arrival of our first Gray catbird, Brown Thrasher, Indigo Bunting, Great Crested Flycatcher, Least Flycatcher, Scarlet Tanager, and many species of warblers, Town of Cooperstown, Manitowoc County (Joel Trick).

First calling Gray Treefrogs, Town of Cooperstown, Manitowoc County (Joel Trick).

Golden currant (Ribes odoratum) first open flowers, UWGB. This is basically a horticultural species in this area, rarely if ever found outside of cultivation, though it may persist for years on abandoned home sites. Also first flowering for Yellow trout-lily (Erythronium americanum), two-leaved toothwort (Dentaria diphylla), common blue violet (Viola sororia), long-beaked sedge (Carex sprengellii), wild gooseberry (Ribes cynosbati) and Canada wild plum (Prunus nigra), UWGB (Gary Fewless). Also the horticultural species Japanese Yew (Taxus cuspidata) is in anthesis, UWGB (Gary Fewless).

Today we had our first Ruby-throated Hummingbird taking nectar at our feeder, Town of Cooperstown, Manitowoc Co. (Joel Trick).

Heard my first of the year Black-throated Green Warblers singing today, Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler).

Wild strawberry (Fragaria virginiana) in flower, UWGB (Gary Fewless).

Northern oriole arrived today, has been using our nectar feeder. Also new are Sedge Wrens and Tennessee Warblers, Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler).

A few Four-toed Salamanders (Hemidactylium scutatum) at nesting sites. West-central Marinette County (Steve Price).

First Wood anemone (Anemone quinquefolia), Yellow Trout Lily (Erythronium americanum) and the first violet I have been able to confirm is Dog violet (Viola conspersa). Also first Red Admiral butterfly and Cabbage butterfly. Baird Creek Parkway, City of Green Bay (Gary Fewless)

First downy yellow violet (Viola pubescens) Brown County, Town of Scott.
Yellow rocket (Barbarea vulgaris) & green ash (Fraxinus pennsylvanica) in flower, Allouez.
Swamp buttercup (Ranunculus hispidus), false rue anemone (Isopyrum biternatum) in flower, UWGB (Gary Fewless).

Two Nashville Warblers seen among many Yellow-rumped Warblers; one Solitary Sandpiper, Manitowoc County near Lake Michigan, Town of Centerville (Jon Reisenbuechler).

First white-crowned sparrows, clay-colored sparrow, rose-breasted grosbeak, Town of Cooperstown, Manitowoc County (Joel Trick).

A few horticultural trees of Norway maple (Acer platanoides) in flower, City of Green Bay (Gary Fewless).

First flower (anthesis) for paper birch (Betula papyrifera); first open flowers of Spring Beauty (Claytonia virginica) for UWGB (Gary Fewless). Spring beauty flowered 10 days later than the 18 year average.

Several tree species are leafing out far enough to give a slight green caste to some woods. Box elder (Acer negundo) is the most conspicuous in this regard, but others include crack willow (Salix fragilis) and some quaking aspen (Populus tremuloides), plus the shrubs Bell's honeysuckle (Lonicera xbella) and American wild currant (Ribes americana), (Gary Fewless).

I have a couple of reports of blue violets in flower without positive identification. Usually, the first two blue violets to flower are dog violet (Viola conspersa) and wood violet (V. sororia), in that order, but I can't be sure without seeing the plants.

Wild ginger (Asarum canadense) in flower, UWGB (Matt Welter).