Red cedar with cedar apple rust


(Dan) #1

In 2018 I collected a Red Cedar yamadori in eastern NC that had been growing atop of a concrete slab. I am aware that eastern red cedar is not your typical bonsai material for multiple reasons. This tree however does have great movement on lower portion of the thunk. Essentially the tree could be collected without having to use any tools. The collection location was also less than 150 yards from my home so I went for it. Fast forward to spring 2019 and the tree is showing tons of new growth as well as cedar apple rust on about 2/3 of the branches. The tree branching is very spacer so pruning off the infected areas would be a death sentence. My neighbor has a apple tree less than 100 yards from my bonsai collection, collected red cedar and several wild red cedar trees are growing in the area. This makes me believe that cedar apple rust disease is here to stay. While checking the tree this morning 3/2/19 the rust has grown. Attached are photos of the red cedar.

My question’s are:

  1. Can cedar apple rust effect other species of Junipers or just red cedar and apple trees?
  2. My entire bonsai collection is located within this mess. I have several species of Junipers, 4 black dragon cryptomeria, 2 Hinoki Cypress, spruce and JBP’s. Do these trees have the possibility of becoming infected?
  3. What are some possible options for the infected red cedar? replant at original collection sight, trunk chop and graft, keep in grow box, total removal…anything ?

Thanks in advance and I look forward to your advice.


(Jonas Dupuich) #2

I haven’t dealt with cedar apple rust specifically, but I have dealt with other fungi. I’d start with whatever contact sprays are available that list cedar apple rust on the label and consider using a systemic if that’s indicated for the rust.

As for the other trees, it could be a good time of year for a dormant spray like copper or Bordeaux mix:
https://www.facebook.com/notes/houston-bonsai-society/lime-sulfur-and-bordeaux-mix/2200906759939935/

Would be great to hear from someone who’s dealt with cedar apple rust on red cedar.


(Chris Hayhurst) #3

I have had it on my trees. What I learned is you cannot get rid of it, treatment is for prevention only. The Galls will swell into disgusting slimy gelatinous masses when it gets rainy and they will release spores that will infect the nearby apple trees only. But next year the spores will fly again, this time they will only infect junipers. The only solution is to cut and burn all infected material. Yes other junipers can get it, I lost a Japanese dwarf juniper, a Chinese Juniper and I heavy pruned branches on a San Jose Juniper and one on my Red Cedar. If you effectively prune you can save the tree but not the infected material. As I am now aware it’s around I have been spraying spring and fall with Monteray Fungi Fighter and have not seen further infection in 4 or 5 years. https://www.amazon.com/Monteray-MONTEREY-FUNGI-FIGHTER/dp/B005G6J2SO
I think it’s mancozeb
Good Luck


(Dan) #4

Thank you for that helpful information. I have since disposed of the infected red cedar but am surrounded by other infected red cedar trees. Do you think it is too late this year to spray my junipers? Eastern NC Zone 8.


(Chris Hayhurst) #5

It can’t hurt, In that you already have it, it may spread further or you could be in the process of infection. What you have could have spread (airborne) last fall and is headed back to the apples this spring or it could have just infected your trees this spring and is waiting to mature. I would spray now and in 10 days. It’s a 2 year cycle, I had thought that it was alternating years but there’s probably apples and junipers infected this year and they will all infect there counterparts simultaneously. I was told to spray spring and fall. Google it’s cycle for more info.