Is it safe to plant vegetables in a garden which had peonies grown in it for 25 years, but the peonies were recently dug up and vegetables Just planted where the peonies were. Is this safe for humans to then eat these vegs.?
Thank you for your question to Toronto Master Gardeners.
I could find no reference to peonies having a long-term toxic effect on soil. There have been some studies linking peony roots to low danger toxins but there’s nothing out there to suggest the effect stays in the soil. In fact, the roots are considered edible by some, and the leaves can be added to jams and jellies, according to some recipes. Your vegetables should be safe to eat.
Attached is a link to a question similar to yours that we answered previously. In it is a link to further information:
I would like to know if Peony flowers are poisonous.
Would it be just the stem or the flowers?
Could a peony go on a cake?
The use of edible flowers in cooking has a long history, and continues to hold our interest today – not surprisingly, for the colour and beauty that flowers bring to our culinary creations.
As a general rule, whatever edible plant you plan to use, there are some important considerations. Plants that have been subjected to pesticides or chemicals should not be eaten, nor should plants be harvested from polluted areas such as roadsides. You should be able to identify your plant without any question.
Confusingly, while the peony (Paeonia lactiflora) appears on many lists of edible flowers, it also appears on lists of poisonous plants, for example, this list prepared by Toronto’s Hospital for Sick Children, here. The Illinois Poison Centre classifies the peony’s toxicity as a “1” on its ranking scale of from 0 (non-toxic) to 3 (highly toxic) indicating that symptoms may occur which are mild and not life-threatening. Eating the rhizomes, seeds, or flowers of the peony can cause nausea, vomiting, abdominal pain or faintness. All parts of the peony are considered toxic to dogs, horses and cats. Paeonol, found in the root of Paeonia lactiflora, is a component used in traditional Chinese medicines, and is the subject of current research on its pharmacological functions, including anti-oxidative, anti-inflammatory and neuroprotective activities.
A previous Toronto Master Gardeners post (although written in response to a question about honeysuckle) provides some good resources for identifying edible flowers, and also offers good basic advice: https://www.torontomastergardeners.ca/askagardener/is-dropmore-scarlet-an-edible-honeysuckle/.
You could use your peony flowers to decorate the edges of your cake plate, but they should be removed before eating.