
Completely Arbortrary
Tree advocate Casey Clapp and his tree-curious friend Alex Crowson bring you a podcast about trees and other related topics. History, culture, art, religion, science... trees affect and are affected by everything. Join Casey and Alex on their silly and educational journey to prove it.
Latest episodes

Jun 7, 2025 • 51min
Parthenocarpy (Paperbark Maple)
Parthenowhatnow? Parthenocarpy! Why are 90% of the paperbark maple's (Acer griseum) infertile? Only nature knows.Completely Arbortrary is produced and hosted by Casey Clapp and Alex CrowsonSupport the pod and become a Treemium MemberFollow along on InstagramFind Arbortrary merch on our storeFind additional reading on our websiteCover art by Jillian BartholdMusic by Aves and The Mini-VandalsSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

May 29, 2025 • 57min
Trunk Drawer (Governor's Plum)
It's a bit of governor's plum, innit? (Flacourtia indica) But where to put it? This wayward species finally found a home with the willows, but what happens to those unlucky species who spend their lives in the taxonomic junk drawer?Completely Arbortrary is produced and hosted by Casey Clapp and Alex CrowsonSupport the pod and become a Treemium MemberFollow along on InstagramFind Arbortrary merch on our storeFind additional reading on our websiteCover art by Jillian BartholdMusic by Aves and The Mini-VandalsSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

May 22, 2025 • 1h 6min
Bean Leaves in Bondage (Silk Tree)
Let's get kinky with the silk tree (Albizia julibrissin). This beautiful tree has a very curious way of keeping its leaves close to the stem. Then we finish our game series Fight Shrub!Completely Arbortrary is produced and hosted by Casey Clapp and Alex Crowson Support the pod and become a Treemium MemberFollow along on InstagramFind Arbortrary merch on our storeFind additional reading on our websiteCover art by Jillian BartholdMusic by Aves and The Mini-VandalsSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

May 15, 2025 • 54min
Reversion Therapy (White Spruce)
What happens when a tree mutates? In the case of the white spruce (𝘗𝘪𝘤𝘦𝘢 𝘨𝘭𝘢𝘶𝘤𝘢) it creates a dwarf version of itself. But that version doesn't always grow that way forever. Then, we have the second round of Fight Shrub!Completely Arbortrary is produced and hosted by Casey Clapp and Alex CrowsonSupport the pod and become a Treemium MemberFollow along on InstagramFind Arbortrary merch on our storeCover art by Jillian BartholdMusic by Aves and The Mini-VandalsEpisode cover photo by See Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

May 8, 2025 • 1h
Fight Shrub (Butternut)
Put up your dukes, for a battle between the city, the people, and the trees. At the center is butternut (Juglans cinerea), and it's shading you, your neighbor, and your neighbor's neighbor. Then we play a new game with one rule... you do not talk about Fight Shrub.Completely Arbortrary is produced and hosted by Casey Clapp and Alex CrowsonSupport the pod and become a Treemium MemberFollow along on InstagramFind Arbortrary merch on our storeFind additional reading on our websiteCover art by Jillian BartholdMusic by Aves and The Mini-VandalsSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

May 1, 2025 • 57min
What a (Knobcone Pine)!
Who started the fire? It may have been the knobcone pine (Pinus attenuata) in a ditch attempt to RELEASE THE SEEDS! This curious pine has a curious way of dispersing which includes fire, cones, and cannibalism.Completely Arbortrary is produced and hosted by Casey Clapp and Alex Crowson Support the pod and become a Treemium MemberFollow along on InstagramFind Arbortrary merch on our storeFind additional reading on our website Cover art by Jillian BartholdMusic by Aves and The Mini-VandalsSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Apr 24, 2025 • 44min
Anomalous Secondary Growth (Ombú)
Anomalous secondary growth! What in the world is it? Just ask the ombú (Phytolacca dioica), pokeweed’s tree-like cousin. It doesn’t make wood, it makes “anomalous secondary growth”, an endlessly interesting way to grow. Then, we answer a question about the perfect flower/tree pairings.Completely Arbortrary is produced and hosted by Casey Clapp and Alex CrowsonSupport the pod and become a Treemium MemberFollow along on InstagramFind Arbortrary merch on our storeFind additional reading on our websiteCover art by Jillian BartholdMusic by Aves and The Mini-VandalsSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Apr 17, 2025 • 56min
Golden Cone Ratio (Austrian Black Pine)
The Golden Ratio: a fact of life on Earth, or an copy and pasted alien blueprint? Perhaps the answer lies in the cones of the Austrian black pine (Pinus nigra). Let’s discuss Phyllotaxis, the mathematical means by which plants remain in light.Completely Arbortrary is produced and hosted by Casey Clapp and Alex CrowsonSupport the pod and become a Treemium MemberFollow along on InstagramFind Arbortrary merch on our storeFind additional reading on our websiteCover art by Jillian BartholdMusic by Aves and The Mini-VandalsSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Apr 10, 2025 • 4h 10min
BONUS: Lord of the Tree Rings Marathon
What's up, Middle-Earthlings! Casey and I are taking a much-needed break this week, and so we present to you a hilariously massive extended edition episode that includes all three episodes of our Lord of the Tree Rings series, originally published in March of 2022. New episodes starting next week! Take care, everyone.Completely Arbortrary is produced and hosted by Casey Clapp and Alex CrowsonSupport the pod and become a Treemium MemberFollow along on InstagramFind Arbortrary merch on our storeFind additional reading on our websiteCover art by Jillian BartholdMusic by Aves and The Mini-VandalsSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.

Apr 3, 2025 • 1h
Inside Sprout: Joy (Money Tree)
What makes you happy? Is it money? Or maybe it’s the money tree (Pachira aquatica). This famous houseplant is also a forest tree, so why did it become synonymous with feng shui, harmonious qi, and interior design? Then we play a new game of Happy Go Lucky!Completely Arbortrary is produced and hosted by Casey Clapp and Alex CrowsonSupport the pod and become a Treemium MemberFollow along on InstagramFind Arbortrary merch on our storeFind additional reading on our websiteCover art by Jillian BartholdMusic by Aves and The Mini-VandalsSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.