Rust on Serviceberry and... - Ask Extension
Hi - I have a serviceberry that is healthy and about 4 years old - no problems other than rust on the berries for the past two years. The cedars infec...
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Rust on Serviceberry and... #862502
Asked March 25, 2024, 7:32 PM EDT
Hi - I have a serviceberry that is healthy and about 4 years old - no problems other than rust on the berries for the past two years. The cedars infecting them are not on my property sadly.
I had someone from Chesapeake Raincheck program come out and inspect it last year and he mentioned I could use a copper fungicide on the serviceberry as long as it was on the OMRI list - so i hope to spray this year. My questions are:
- When should I start to spray and how often?
- Can I eat the berries if I wash them after I spray? Does it harm the birds that will eat them
- Can i use the copper fungicide to help my poor dogwood that struggle with fungus, and on my roses to help with blackspot?
Thx
p.s. are the Cicadas going to be bad here this year or are we in decent shape - last time they damaged a lot of my hardwood small trees and shrubs.
Prince George's County Maryland
Expert Response
Copper-based fungicides are broad-spectrum (affecting a range of fungi and some bacteria) but are not foolproof, so depending on how weather patterns impact a spray routine (as multiple applications will be needed to maintain protection against infectious spores), it's possible some rust infection will still take place. Copper has limits on how many applications can be made per year since you do not want it reaching root-toxic levels in the soil over time. You will have to refer to product label directions for use regarding how often to spray and when to begin. Often, sprays must start before the infection cycle begins, which will be right now since rust fungi are beginning to produce spores on their juniper host plants. Do not spray the tree while flowers are open to avoid pollinator exposure.
If the fungicide is one that is labeled for use on edible plants, then it will tell you when the last date to spray is prior to harvest of fruit (might be listed as "pre-harvest interval", PHI, or similar terminology). Do not use a fungicide not labeled for use on edible plants for something you intend to harvest/consume.
You can use a broad-spectrum fungicide like copper for other diseases, but check the label since this can depend on the formulation. Black spot on roses will probably be suppressed by sprays (here too, there will be multiple applications needed per season, which may not be practical or inexpensive), but as for the dogwood's infection(s), that will depend on what disease it is affected by. Powdery mildew is common, as is Elsinoe leaf spot. You can visit our dogwood diagnostic page for more information about typical ailments.
Only a portion of St. Mary's County will be affected by periodical cicada emergence this year. No other part of Maryland contains this brood of cicadas, and in some cases local media is misleading their audience (even if unintentionally) about the cicada emergence this year.
Miri
If the fungicide is one that is labeled for use on edible plants, then it will tell you when the last date to spray is prior to harvest of fruit (might be listed as "pre-harvest interval", PHI, or similar terminology). Do not use a fungicide not labeled for use on edible plants for something you intend to harvest/consume.
You can use a broad-spectrum fungicide like copper for other diseases, but check the label since this can depend on the formulation. Black spot on roses will probably be suppressed by sprays (here too, there will be multiple applications needed per season, which may not be practical or inexpensive), but as for the dogwood's infection(s), that will depend on what disease it is affected by. Powdery mildew is common, as is Elsinoe leaf spot. You can visit our dogwood diagnostic page for more information about typical ailments.
Only a portion of St. Mary's County will be affected by periodical cicada emergence this year. No other part of Maryland contains this brood of cicadas, and in some cases local media is misleading their audience (even if unintentionally) about the cicada emergence this year.
Miri
