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Potpourri preservation

By David Shaw, 8 March 2018

Learn about the different parts of plants, as well as the science of preservation, by making your own pretty potpourri.

Safety: Vegetable peelers are sharp. Ask an adult to help.

You will need

• Flowers – we used roses
• Orange
• Cinnamon stick
• Vegetable peeler
• Paper towel

What to do

1. Put some paper towel on a table. We used about 8 sheets.
2. Carefully remove the petals from your flowers. Lay the petals spaced out on the paper towel.
3. Ask an adult to help you use a vegetable peeler. Carefully cut strips of peel off an orange. Lay these out on paper towel too.
4. Leave the petals and peel to dry for a few days, turning them over once or twice a day.
5. When the petals are dry and crinkly and the peel is hard, they are ready! (If the petals or peel look strange or smell bad, throw them out. Something may have gone wrong in the drying process.)
6. To mix up your potpourri, put the petals and peel into a bowl. Take a cinnamon stick, break it in half and add it to the bowl. Mix it around a bit and take a sniff – does it smell nice?

What’s happening?

Drying is a wonderful way to preserve plant parts. Botanists also use this process to preserve scientific specimens in herbariums.

This potpourri uses three different parts of a plant. Petals are parts of flowers, peel is part of a fruit, and cinnamon sticks are actually dried bark!

In nature, flowers have one job – they are there to reproduce. Flowers are pretty and smell to attract animals, spread their pollen and receive pollen from other flowers. When the flower is pollinated, its job is finished, and the plant will try to recover nutrients from flower petals. In this process, the petal loses its smell and goes brown.

When we dry petals, we interrupt this process. The colour and smell chemicals in the petals are not broken down and are instead preserved.

Drying also preserves the smell from fruits and bark, but they have slightly different reasons for their scents.

The purpose of a fruit is to be eaten, so it smells to attract animals too. Inside the fruit, there are seeds which don’t get digested like the fruit does. Instead they get pooped out, far away from where they came from, in a pile of manure fertiliser, ready to grow into new plants.

Most bark doesn’t smell very much, but cinnamon bark is unusual. It contains a chemical called cinnamaldehyde, which gives cinnamon its smell. This chemical is also a fungicide, an insecticide, and can repel some animals. This protects the plant from many threats. It’s quite surprising that we humans actually like the smell!

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