Long day length, warm spring temperatures, and the first day of summer are among the highlights of gardening in June. This month brings exuberant plant growth, flowering, nesting birds, seedlings, and pollinator activity. Garden tasks include planting, weeding, edging, and monitoring plants and bumble bees. This year we are adding a short profile prairie garden, inspired by Black Earth Rettenmund Prairie State Natural Area in Western Dane County. Also, gardeners’ and visitors’ observations and questions are providing topics to explore and share.
When describing plants and animals in the garden, I include the common name along with the scientific name. Common names are not always unique to a single species, but the scientific name is. A plant may have several common names, or a common name might be regional or used for more than one species. Occasionally, more than one scientific name is used to taxonomic revision and the changeover to the new name. I use the Flora of Wisconsin as my authoritative source for plant names.
Flowering in June, the honeysuckles (native and non-native) can be easily distinguished. Native northern bush-honeysuckle (Diervilla lonicera) is a small shrub with arching stems. It grows well in well-drained, even dry, soils in partial shade. It can be grown in a row to form a border, or in masses. It is a valuable resource for pollinators. Another native, limber honeysuckle (Lonicera dioica) is a desirable woody vine, with flower clusters held above circular leaves. As a reader points out, in this group the exact scientific names are important, if you want to avoid planting or fostering bush honeysuckle (Lonicera x bella) and other related invasive shrubs that can be in gardens and landscaping but may move into restorations through birds dispersing the seeds.
Another visitor asked about the differences between two members of the carrot family, golden Alexanders (Zizia aurea) and yellow-pimpernel (Taenidia integerrima). The former has toothed leaflets and the latter is not toothed. Both bloom in May and June and have tiny yellow flowers arranged in compound umbels. The flowers are more tightly arranged in golden Alexanders and loosely arranged in yellow-pimpernel. The flowers of both species are attractive to early season pollinators, mostly small bees and flies. They are host plants for black swallowtail butterflies (Papilio polyxenes asterius). They both grow well in semi-shaded sites, are smaller in size, and usually flower well before the non-native biennial yellow parsnip (Pastinaca sativa). Use caution when handling plants in this family—use gloves and long sleeves, especially if you are removing yellow parsnip.
A reader from the northeast United States asked about a group of colonial larvae found feeding on goldenrod leaves. My research yielded only one photo that matched the larvae, suggesting that the adult would be northern crescent butterfly (Phyciodes selenis); it is colonial as early stage larvae and solitary in later stages, feeding on plants in the aster family. The crescents are a confusing group taxonomically, which adds to the uncertainty. The reader may rear a few larvae to photograph the adult. I also recommended submitting the photo of the larva to BugGuide.net for help with identification and to build more records. The habitat in the reader’s area and the abundance of known adult butterfly host plants there support the tentative identification. Anyone can make valuable contributions to our knowledge of little-known garden denizens.
The wild roses in the native plant garden (Rosa blanda, R. arkansana, and R. carolina) began blooming in late May. Those have pink open flowers with five petals and many stamens. In June, bumble bee (Bombus spp.) colonies are building in size, with female workers out foraging on roses and the foundress queen usually remaining in the nest, laying eggs. Join Bumble Bee Brigade (coordinated by the Wisconsin Department of Natural Resources) to contribute your observations and learn more about Wisconsin’s bumble bees. This month, solitary leaf cutter bees (Megachile spp.) may use rose leaves and petals to line chambers in crevices and hollow stems where they leave provisions (primarily pollen) and lay their eggs with the provisions. The most easily observed evidence of this might be circular pieces missing on the roses.
Seeing patterns, making connections, and noting your observations and contributions are all great ways to enjoy your garden in June and beyond.
—Susan Carpenter, native plant gardener