Are oak leaves poison to vegetable garden ? - Ask Extension
Relative neighbors say oak leaves are poison to garden. They recently said they mulched and filled nine large bags of oak leaves and took to landfill...
Are oak leaves poison to vegetable garden ? #435557
Asked November 29, 2017, 5:39 AM EST
Relative neighbors say oak leaves are poison to garden. They recently said they mulched and filled nine large bags of oak leaves and took to landfill.
I said they could drop off with me since I mulch mainly with kitchen vegetable, coffee grounds, egg shells, etc.
Neighbors said the oak leaves were poisonous to vegetable gardening which they do a lot of and to plants & flower gardens at our home.
Please advise any caution with east coast oak tree leaves being used as mulch.
Sussex CountyNew Jersey
The simple answer is no, oak leaves are not poisonous to a vegetable garden.
The longer answer is: Oak leaves have high levels of tannins, which are somewhat acidic. If you were to eat copious amounts of the leaves or acorns directly, they might make you or an animal sick (see Illinois Poison Center info: http://illinoispoisoncenter.org/plant-list).
Oak leaves also tend to break down/decompose slowly. If you plan to use them as part of your garden mulch/compost, shred them so they break down more quickly. They'll likely be one of the last items to break down, and some gardeners use them as mulch for just that purpose.
If you can compost these leaves before you put them in your vegetable garden, you may have more success because they'll break down faster and offer more nutrients. Here is some basic information about composting, which mentions oak leaves: https://extension.illinois.edu/hortihints/0010a.html
This work is supported in part by New Technologies for Ag Extension grant no. 2020-41595-30123 from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.