Can this tree be saved? - Ask Extension
I'm a volunteer at the Annapolis Maritime Museum in Eastport. This Easter Red Cedar (Juniperus virginian) had an industrial strength infection of bag ...
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Can this tree be saved? #791633
Asked May 19, 2022, 12:10 PM EDT
I'm a volunteer at the Annapolis Maritime Museum in Eastport. This Easter Red Cedar (Juniperus virginian) had an industrial strength infection of bag worms last year. The museum had it sprayed twice by a local company. I estimate that 1/3 of the tree has been defoliated. From the ground, I can't determine if the defoliated upper branches are leafing out. The lower half of the tree seems robust. Some say the tree is dead and it should be cut down. I would like to save it if possible. Should: I take a wait and see if the upper branches leaf out, consider removing the upper branches or cave into the "cut it down" movement?
thank you,
dennis
Anne Arundel County Maryland
Expert Response
Hello Dennis,
Conifers like Eastern Redcedar don't typically replace lost foliage, so unfortunately bare areas won't fill back in again, even if the branch tips are viable and buds break from there. For aesthetic reasons, you'd probably have to have the entire bare portion of the tree removed, though for ecological considerations if could be useful to retain it as songbirds or raptors may enjoy perching up there where they get a good view of their surroundings.
Hopefully the company used a spray with minimal ecological impacts; Eastern Redcedar is a host plant for the oft-unseen Juniper Hairstreak butterfly, and many birds enjoy eating the berries. Two options when pesticide is needed to suppress an extensive bagworm population are the active ingredients Bt (Bacillus thuringiensis) and spinosad. (Use one or the other separately, not combined.) Bt works best on young caterpillars, and bagworm is either just about to hatch within the next week or so or has already done so recently. Spinosad is the better solution if the window to treat with Bt is missed and caterpillars/bags are already half-grown or larger. Neither should have any significant impacts on other wildlife with the exception of the butterfly above, since no pesticide that works on caterpillars can discriminate between moth larvae and butterfly larvae.
Since Eastern Redcedar has good wildlife value overall, it's worth keeping in our opinion, despite its susceptibility to bagworm outbreaks and rust fungi. The tree is definitely not dead, or else its foliage would be unmistakably and completely orange- or tan-brown. Given enough time and a successful suppression of bagworms, the remaining live top growth will replace some of the upper growth that was lost/removed, though it may not have the same canopy shape as it originally did.
Miri
Conifers like Eastern Redcedar don't typically replace lost foliage, so unfortunately bare areas won't fill back in again, even if the branch tips are viable and buds break from there. For aesthetic reasons, you'd probably have to have the entire bare portion of the tree removed, though for ecological considerations if could be useful to retain it as songbirds or raptors may enjoy perching up there where they get a good view of their surroundings.
Hopefully the company used a spray with minimal ecological impacts; Eastern Redcedar is a host plant for the oft-unseen Juniper Hairstreak butterfly, and many birds enjoy eating the berries. Two options when pesticide is needed to suppress an extensive bagworm population are the active ingredients Bt (Bacillus thuringiensis) and spinosad. (Use one or the other separately, not combined.) Bt works best on young caterpillars, and bagworm is either just about to hatch within the next week or so or has already done so recently. Spinosad is the better solution if the window to treat with Bt is missed and caterpillars/bags are already half-grown or larger. Neither should have any significant impacts on other wildlife with the exception of the butterfly above, since no pesticide that works on caterpillars can discriminate between moth larvae and butterfly larvae.
Since Eastern Redcedar has good wildlife value overall, it's worth keeping in our opinion, despite its susceptibility to bagworm outbreaks and rust fungi. The tree is definitely not dead, or else its foliage would be unmistakably and completely orange- or tan-brown. Given enough time and a successful suppression of bagworms, the remaining live top growth will replace some of the upper growth that was lost/removed, though it may not have the same canopy shape as it originally did.
Miri
