Extension

Now that we’ve sprung forward, the days are longer, and gardeners are itching to get to work in the landscape. While some people take time to do traditional spring cleaning inside, gardeners should take some time to clean up their garden spaces.

 

Why tidy up the garden? Well, for one, it just looks nicer without all the dead stems and foliage. Gardeners who may have had issues with infected and diseased plants should remove that dead debris to reduce the chances of those organisms infecting new growth. Plus, removing dead plants and leaves gives way to the sun warming the soil and providing space for the new plants.

 

However, before jumping in with lopping shears, check the standing spent plant stems. Recent research has shown that these dormant habitats have an impact on native bees and beneficial insects. Cavity nesting bees and some solitary wasps use hollow or pithy stems to construct nests.

 

Horticulturists at the Lurie Gardens in Chicago have shared valuable information they’ve gathered about these habitats. These experts have discovered that sturdy, fibrous stems with pithy, hollow centers are great for stem nesting bees. They typically nest in the lower 24 inches of the stem.

 

Plants that are good hosts for native bees and solitary wasps include Monarda fistulosa, Rudbeckia sp., Echinacea sp., Solidago sp., Aster sp., Asclepias incarnata, Vernonia sp., Veronicastrum virginicum, Agastache sp., and Hydrangea arborescens. Other species that the Lurie Gardens are experimenting with include Phlox paniculata, Eutrochium maculatum, and Actaea sp.

 

By leaving some of these stems intact throughout the year, gardeners are preserving the bees’ habitat and hopefully increasing the population of important pollinators. Leaving stubble that is 18-24 inches high in the garden may seem unsightly at first, but as the new growth develops in the spring, those stems will soon be hidden and may even provide additional support to the new growth.

 

Go ahead and cut back plants without pithy, hollow stems, including some ornamental grasses and perennials as new growth will emerge soon, which can make it difficult to remove dead foliage without damaging the new growth. Debris that hasn’t been infected with pests can be left in the garden as a mulch or it can be composted.