This is a selective list of popular blooming horticultural plants in Longenecker Horticultural Gardens (LHG) and native plants in the Wisconsin Native Plant Garden (WNPG) and natural areas. Estimated bloom times are approximate and can change due to weather. Bloom dates will be noted in bold once buds have begun to open (this does not reflect peak bloom). For native plants, additional location might also be listed. Dates will be updated weekly.

Longenecker Horticultural Gardens

• Cherries (Prunus spp.): early to mid-April / April 23
• Magnolias (Magnolia spp.): April–May / April 17
• Crabapples (Malus spp.): April–May / May 7
• Lilacs (Syringa spp.): April–May / April 30
• Rhododendrons and azaleas (Rhododendron spp.): mid-April–May / April 24
• Horsechestnut/Buckeyes (Aesculus spp.): mid-May / May 26

May 15 bloom update: Magnolias are past peak, but a few trees still have good bloom display that should last through the weekend and into next week. The majority of crabapples are in bud or blooming. Peak bloom should begin this weekend and go through next weekend. Due to last year’s wet and cloudy growing season and the winter’s extreme cold, the lilac display will not be as robust as usual. About 40% of the collection will have few to no blooms. The rest of the lilac collection is either in bloom or will begin to bloom soon. Peak bloom should start this weekend and continue through next weekend. As always, bloom times and duration are weather dependent.

May 10 bloom update: While a few lilacs and crabapples have started to bloom, the cool temperatures and cloudy days have slowed progress. Some of the late-flowering magnolias are in bloom. Sun and warmth should help the lilacs and crabapples along, and the crabapples are likely to have more blooms this weekend than the lilacs, but substantial bloom for both is still a week away (if weather stays warm and sunny).

May 1 bloom update: the April 27 snow and cold was milder than forecast and magnolias suffered little damage. However, those that were in full bloom are now fading. Those that are just beginning to bloom should be in full bloom this weekend (May 4–5), and those yet to bloom should start in the next week. Cherries should be in bloom through the weekend. Lilacs are just beginning, it will be another 7–10 days for many lilac blooms. Crabapples are leafing out and should bloom in 7–10 days.

April 26 bloom update: About 40 percent of the magnolia collection is in bloom. Once flowers are open, they are easily damaged by cold. If we get the mid-20s forecasted for overnight Saturday, all the open flowers will wither. Some magnolias are just starting to bloom, and the mid- and late-season trees haven’t started to bloom yet. The cold may damage those just opening, and we hope there will be little damage to those not yet flowering. So the good news is that about 40% of the collection still has potential to bloom after Saturday’s weather. Cherries have only a light bloom this year. The extreme cold in late January killed most of the flower buds, and those in bloom will likely lose flowers due to cold this weekend. Crabapples and lilacs are not yet blooming and will likely come through Saturday’s cold without damage.

Native Plants

Native plants generally bloom in the garden earlier than the same plants growing in the natural areas.

• Skunk cabbage (Symplocarpus foetidus): February–April / March (Skunk Cabbage Wetlands)
• Toothwort (Cardamine concatenata): April–May / April 8 (Wingra Oak Savanna)
• Trout-lily (Erythronium spp.): April–May / April 8 (Wingra Oak Savanna)
• Hepatica (Anemone acutiloba): April / April 22 (WNPG)
  
• Pasqueflower (Anemone patens): April
• Prairie-smoke (Geum triflorum): April-May / April 22 (WNPG)
  
• Bloodroot (Sanguinaria canadensis): April–May / April 8 (Wingra Oak Savanna)
• Wild ginger (Asarum canadense): April–June / May 1 (WNPG)
• Dutchman’s breeches (Dicentra cucullaria): April–May / April 22 (WNPG)
  
• Virginia bluebells ( Mertensia virginica): April–May / April 25 (WNPG)
  
• Woodland phlox (Phlox divaricata): May–June / May 5 (WNPG)
• Wild geranium (Geranium maculatum): May–June / May 14 (WNPG)
• Trillium (Trillium spp.): May / May 15 (WNPG)
• Shooting star (Dodecatheon meadia): May / May 10 (WNPG)
• Wild lupine (Lupinus perennis): May–June / May 16 (WNPG)
• Indigos (Baptisia spp.): May–July
• Spiderwort (Tradescantia ohiensis): late May–June
• Milkweed (Asclepias spp.): June–August