Jellies invade Pontiac trees

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Kate Aley

I've always wanted to write a sensationalistic headline like that

The jellies are real however.

This month, reports have come in of juniper trees hung with these strange, amazing and reasonably disgusting-looking star-like jelly shapes: a fungus? a flower? Let's ask Dr. Internet.

Turns out these weird formations are a symptom of Juniper-Hawthorne rust, a plant disease closely related to Cedar-Apple rust.

According to Rob Sproule of SalisburyGreenhouse.com (a gardening website from Alberta), infected junipers (or cedars with a related condition) become hung with gelatinous orange blobs along their branches, generally if the month of June has been especially wet. 

"They look like orange octopuses, with slimy tentacles called teliohorns dangling from the main gooey mass," writes Sproule. "Each teliohorn has thousands of spores inside of it just waiting to catch a ride on the breeze and ride through the garden.  When they mature in mid-summer, the dispersing spores can only latch on to a specific secondary host. In the case of Juniper-Hawthorne rust, the spores travel from their primary host (junipers) to their secondary hosts (hawthorne, mountain ash and apples)."

According to the Salisbury website, junipers are not damaged by the attack. However, if it gets to apple trees, it can lead to 'significant defoliation and reduced fruit yield'. 

"The secondary hosts don’t acquire the gelatinous teliohorns. They get rust spots on their leaves that are orange with dark red to black centers. In the late summer, a different kind of spore blows from the secondary host back to the primary, where it lurks over winter until it can re-emerge in the spring," writes Sproule.

Luckily, there is an relatively easy fix for this.

"Whether you can catch the growing gall [pictured below] or find the unmistakable orange blob the next spring, it’s important to remove the growth before it spores and damages the secondary hosts. Cut all infected branches eight inches from the growth. Burn the fungus and disinfect your tools with a light bleach solution," Sproule advises.

"If it’s already on your apples, hawthorne or ash trees, remove as many infected leaves as feasible. The fewer leaves there are, the fewer spores will find their way back to the primary host to continue the life cycle. As a precaution, if you find the orange blobs you could sprinkle some sulfur dust on the leaves.The best defense is to keep the primary and secondary hosts separate."

Let me know if you've seen any of these hideous delights and, if so, what you plan to do about it.