Moths Infesting Dried Flowers and Herbs
Answered by: Conrad Richter
Question from: Barb Couture
Posted on: December 30, 2003

I started making potpourri from one of your kits a few years ago and enjoyed it so much I began to gather the flowers from my garden and drying them. I ordered all the materials from Richters and the potpourri turned out beautiful.

However, last year I had a problem. I usually hang the flowers in the garage until dry and then bring into the house and hang again in a cool, dry place until I’m ready to begin. Except that this year I had moths flying around and spotted some larvae. I threw everything out and was very disappointed that I couldn’t make it this year.

Can you please tell me what I can do next year to stop this problem? Is there a spray I should be using on the dried or fresh flowers before bringing them into the house?

The larvae are probably susceptible to sprays based on insecticidal soap and pyrethrum, such as Trounce sold by Safers. But you need to experiment to be sure that the spray doesn’t add excessive moisture that interferes with the drying process.

Apparently problems with moths are not that common because most books on drying flowers do not mention this problem. One that does is "Dried Flower Gardening" by Joanna Sheen and Caroline Alexander (Ward Lock, London, 1996). Here is what the authors write about insect damage:

"The main threat of insect damage to stored flowers comes from moths -- or rather from the voracious appetite of their larvae, which can eat away the base of the petals, causing the flowers to fall apart. The most susceptible varieties are peonies, roses, Helichrysum and Centaurea. Putting mothballs in the boxes during storage helps to deter the adult moths from laying eggs (and also discourages mice). If you come across any stored bunches showing signs of damage, discard them (and the box they were packed in) immediately. If you suspect any other bunches of containing eggs or larvae, place them in a sealed plastic bag in the deep freeze for 24-48 hours. It sounds drastic, but usually works."

The problem with mothballs, of course, is that the odour is offensive, and if it lingers it will spoil the scent of the potpourri. Your only options may be the deep freeze tactic or discarding infested batches.

The good news is that you won’t necessarily have the same problem next year. Pest problems like this are often chance events that occur one season and then disappear.

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