The Magick of Oak Galls

I love oak galls so much. They come in so many shapes and sizes and are home to the California gall wasp. It actually looks more like an amber-colored fly more than a wasp. I gathered these from the same Valley Oak just up the road from my forest. Sun exposure, environment, and age affect the color. The pale cream with soft blush marks is my favorite. When gathering oak galls, it’s important to keep a few things in mind. Don’t pick them if they’re green, you’ll kill the wasp larvae. Wait to gather galls until August, September, or even October. I gathered as late as early December in 2020 because of the drought. You’ll want to get them before it rains a lot. The water will leach out the tannins. Only pick them if you can see small holes in the exterior shell. This means the wasps have hatched and left to lay eggs new eggs. Thoughtful gathering is always important. Please follow these simple rules. Take no more than half; sharing is caring. If only a few are left, leave them. There are probably more on a nearby tree. Be gentle. Don’t break off branches. A gentle twist and the gall usually pops right off. I usually bring a clean pair of pruners with me. If there is a particularly beautiful cluster on a dead branch, I’ll clip it off and keep and add it to my curiosity collection. Remember to clean your pruners before using them on another tree. You can spread disease otherwise.

One of the beautiful things about oak galls is that it’s very high in tannins. So it’s both a mordant and a natural dye. It all depends on how you process it. Oak Gall + Iron was the very first natural dye I ever used, and it's still one of my favorites. It creates cool shades of gray with an almost purple undertone on white fabric. For deeper hues, try dyeing natural colored linen. I love combining it with logwood extract. It makes the color of a new moon sky full of magick.

I’ve found that leaves, acorns, and galls all produce different colors. And depending on the species of the oak tree, the leaves also produce a unique color. Oak trees create their own rainbow.

I wrote a book on natural dyes, and it was published in 2025. I have signed copies available in my shop. Dyeing Instructions can be found in my book ‘The Natural Dye Handbook’.

This is an affiliate link to Bookshop.org, which supports independent bookstores. This means that if you purchase through my link, I may earn a small commission, at no extra cost to you. I encourage you to buy my book from your local independent bookstore. Check your local library and see if they have a copy.

You can find sashiko thread naturally dyed with Oak Galls and other natural dye plants in my shop.

I teach Botanical Dyeing at Art Stays at Emandal and at the Fibershed Learning Center in Northern California. If you are interested in exploring your landscape, foraging for plant dyes, and learning more about how different mordants and fabrics affect color, please check out my events page.