Something in the Soil of Santa Chiara

As we begin our last week in Italy, our program has started to slow down; we’ve been focusing on classes and taking fewer day trips. Everyone seems to be worn down from the past five weeks of traveling and being away from home. I do not think it’s bad that things have slowed down at all; this change in pace gives us a chance to appreciate the smaller details of Italian life. In the beginning, we had so much put in front of us so quickly that I don’t think we were able to truly appreciate the little things. Santa Chiara has always been a home base of sorts and I think this change of pace has opened my eyes to how representative it is of Italy as a whole. The plants we find in the courtyard are everywhere in Italy, from the citrus and olive trees to the zonal geraniums that we saw in almost every city. The hydrangeas are the plant I only recently noticed in the courtyard and have seen in almost every garden we’ve visited in Italy. Hydrangeas are ornamental plants that are native to southern and eastern Asia and the Americas. They come in several forms and can be deciduous or evergreen, with the cultivated varieties being deciduous. Flowers appear in the early spring and late fall and can come in the mophead or lacecap forms. These plants are considered natural pH indicators because the color of their flowers varies from pink to blue depending on the amount of aluminum available to them which depends directly on the pH of the soil. Pink flowers appear at a higher pH (6.0-6.2) when aluminum is not available and blue flowers occur at lower pHs (5.2-5.5) when aluminum is present. Acidic soil is preferred by hydrangeas because above a pH of 6.4 they tend to experience an iron deficiency. Iron deficiency is characterized by interveinal chlorosis of the leaves. Since iron is a non-mobile nutrient, the symptoms of iron deficiency first appear in new leaves. So looking at hydrangea growing in Santa Chiara, I can tell a few things about the soil. Since the flowers are pink and the new leaves have interveinal chlorosis, it can be inferred that the pH of the soil is around or above 6.4 and aluminum is either not available or not present in the soil.

Since coming to Italy, I have had the chance to learn more about the cultural history and influence of plants. This study abroad has really opened my eyes to how much plants can tell us, not only about the physical environment but about the people who grow them.
-Lisa C. Maciques