Seeds apparently falling from a red oak


As well as the usual acorns we are finding large numbers of very tiny seeds, apparently falling from our 80′ oak in our back yard. These seeds look like bird seed. Also a larger seed, enclosed in a furry coat is falling, apparently from the same oak.
I’ve never seen these before. The tree had a bumper crop of acorns which the squirells have pretty well stripped clean.

We live in the Beach in Toronto, sandy, well drained soil, many very old oaks and maples.

I’d appreciate your thoughts. Thank you


Thank you for contacting the Toronto Master Gardeners. I think the seed-like things that you have found dropping from your red oak could be oak galls. Galls are irregular plant growths that are caused by the reaction between plant hormones and chemicals produced by some insects and mites as they feed or lay eggs. Galls provide food, shelter and protection to the larvae (often just one) that live inside.

There are at least 750 different galls that have been identified on oak, more than on any other plant. Oak galls vary greatly in size, colour and shape (and yes, some are fuzzy), and where they grow on the plant  eg. leaves, twigs. Many oak gall forming insects are tiny cynipid wasps that are harmless to humans. Many oak galls are formed in the spring / early summer, and the adult insects emerge by chewing their way out of the gall several weeks later. (You could check for exit holes on what has fallen from your tree.) Specific timing is required for insects to initiate the gall, so that the plant will respond and gall growth will begin. There are different lifecycles, depending on the insect species. Some insects have a two year lifecycle, and some overwinter on leaf litter (which would be worth totally removing and disposing of).

I think what you have is leaf gall which is very common in oak trees, and there are many different types. Leaf gall can be unsightly and detract from the beauty of the tree, but it does not damage tree health, and therefore does not generally require any control. Twig galls can be more serious, sometimes killing individual tree limbs or whole trees, so they might need to be pruned out if possible.

I suggest that you check some leaves and twigs on your red oak for the presence of galls, now and in the spring. If you see galls on twigs or branches, you might want to consult an arborist about any action that might be warranted. Landscape Ontario has a list of qualified arborists on their website. Here is a link :


Here are some links with further information about oak galls :


I hope your beautiful red oak will have continued good health !