Located in the marble planters at the entrance to Howlett Hall, the Ericaceous Collection features plants from the botanical family Ericaceae which thrive in low pH, or acid soils.. This photograph represents our gardens before the winter of 2013 when many of our ericaceous plants were lost due to the harsh winter. We are replacing those plants that were lost so that the horticulture classes can continue to learn about ericaceous plants, even though the soil in central Ohio is not suited to these acid loving plants. So, be sure to check back next spring to see what the students and staff have created.
Examples of ericaceous plants include rhododendrons, azaleas, leucothoes, heaths, heathers, and blueberries. Ericaceous plants share similarities in botanical characteristics and also in cultural requirements. Most prefer moist, well-drained, acid soils, protected from strong winds.Central Ohio's soils are not well-suited for ericaceous plants and they are generally not recommended for local landscapes. However, these two large raised planter beds presented the opportunity for horticultural staff to amend and maintain the soil to meet the particular pH requirements for ericaceous plant. Having these plants in the Learning Gardens allows faculty to teach a wider pallet of plants to students, who likewise benefit from studying the plants in a living environment.
To prepare the large container beds, student staff excavated the soil to a depth of two feet and backfilled with a combination of sphagnum peat moss, finely ground pine bark mulch (pine fines), container soil media and sulphur. The soil pH is tested once or twice a year, and sulphur (used to acidify soils) is added as needed.
Many of our ericaceous plants that were lost this past winter are also evergreens that easily desiccate in dry soil and windy winter conditions. Additionally, plants that are grown in containers tend to lose some of their winter hardiness because moisture levels are difficult to maintain, and because their roots don't benefit from added thermal protection of in-ground plantings.