Cedar Color Change

When we saw orange junipers at 45 mph

...we had to pull over to investigate.

Juniperus virginiana (red cedar, eastern red cedar, virginia juniper) is native over half the continent so we are quite accustomed to seeing them all over in our travels. This was the first time we noticed them for such bright color.

Juniperus virginiana (red cedar, eastern red cedar, virginia juniper) is native over half the continent so we are quite accustomed to seeing them all over in our travels. This was the first time we noticed them for such bright color.

The color came from myriad tiny pollen bearing cones, ripening all at once.

The color came from myriad tiny pollen bearing cones, ripening all at once.

When we jostled the branch we stirred up a cloud of pollen. Hay fever sufferers, beware!

When we jostled the branch we stirred up a cloud of pollen. Hay fever sufferers, beware!

The heavy grains fall and would dust everything below.

The heavy grains fall and would dust everything below.

Juniperus virginiana: ...when the staminate yellow-brown cones are swelling and starting to release pollen male trees take on a rather ugly yellow-brown color and are easily distinguished from female trees...
- Manual of Wood Landscape Plants, Michael A. Dirr -

Redcedar: Best seasons: ...Late spring for the telial horns of rust galls, which are as bright as orange Christmas lights...
- Native Trees for North American Landscapes, Guy Sternberg with Jim Wilson -

Cedar rust gall, dormant.

Cedar rust gall, dormant.

What we thought we might find and were glad we did not was a heavy crop of rust galls. Heavy rust on junipers would likely preface a bad year for that rust's alternate hosts, including crabapples, hawthorns and serviceberries. We did find some galls (above) but they were still dormant; the infection cycle's about to begin but not yet underway this spring.

Sometime soon the rust galls will explode in rust spore production. Watching junipers for the appearance of the "Horns" from the galls tells a gardener it's time to protect susceptible crabapples, hawthorns and serviceberry trees.

Sometime soon the rust galls will explode in rust spore production. Watching junipers for the appearance of the "Horns" from the galls tells a gardener it's time to protect susceptible crabapples, hawthorns and serviceberry trees.

More on rust diseases

Junipers' role and controlling the problem on the alternate hosts:

University of Minnesota's Cedar Apple Rust and Other Gymnosporangium Rusts:

http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/cedar-apple-rust-and-gymnosporangium-rusts/

West Virginia University's Cedar-Apple Rust:

http://www.caf.wvu.edu/kearneysville/disease_descriptions/omcar.html