Is this a garlic pest/disease I should be worried about? - Ask Extension
Hi there! Firstly, I have been watching some of your webinars and reading many of your articles, and so so appreciate everything that you offer to th...
Knowledgebase
Is this a garlic pest/disease I should be worried about? #756793
Asked June 17, 2021, 12:19 PM EDT
Hi there! Firstly, I have been watching some of your webinars and reading many of your articles, and so so appreciate everything that you offer to the community.
My concern is with my current garlic crop. I have a mix of hardneck and softneck varieties that I planted in September 2020. I fertilized them with a 3-2-2 mix early this spring, and again in late May. Recently, I noticed that one end of my row of pots is getting these diamond-shaped, yellow and brown spots, and has these little black bugs - not sure if the spotting and the critters are related or not. The other end of my row seems much less affected - there are still yellowing tips and occasional diamond spots, but not nearly as many, and few to none of the bugs.
I gently dug down and it seems like the bulbs are forming okay - I could only see clean, white bulbs, though still small of course. The soil they were planted in was fresh, and I did some supplemental watering during our drier April & May. I live in the Powellhurst area of Portland.
If you have any insight as to what might be the cause of this so that I can help my current crop, or at least avoid this problem in the future, I would be very grateful!
Cheers,
Kayla
Multnomah County Oregon
Expert Response
Hi Kayla- Thanks for your great pictures of your problems with your garlic. We also appreciate your following our webinars and articles. Sounds like you are well on your way to being a master gardener yourself!
Your garlic has a fungus called rust. I'm attaching an article so you can read about it, but it was probably brought on by our weird weather this Spring: cool and rainy promotes the fungus. I also notice the article says don't over apply nitrogen, so it might be worth cutting back on the fertilizer next time. At this time there are no chemicals available for the home gardener (they would have an "H" after them in the article), and this rust will probably not kill the plants before harvest time next month.
I have had rust on my garlic for the past couple of years and the garlic bulbs are just fine to use. For next year, I suggest less dense plantings (maybe only 3 or 4 bulbs per pot), less nitrogen-rich fertilizer, and if you use the same pots, sterilize them with bleach and use new soil.
http://pnwhandbooks.stage.extension.oregonstate.edu/plantdisease/host-disease/garlic-allium-sativum-rust
As to your little black bugs, no, they are not related to the rust. They look like black aphids which can be removed with a spray of water or by hand. Simply wipe them off with a damp rag or tissue. If you do nothing, the ladybugs or lace wings may arrive to take care of them for you, but sometimes this can be a 2 week wait and you might not want to see them all that time.
Carry on with your curiosity and good luck with the garlic!
Your garlic has a fungus called rust. I'm attaching an article so you can read about it, but it was probably brought on by our weird weather this Spring: cool and rainy promotes the fungus. I also notice the article says don't over apply nitrogen, so it might be worth cutting back on the fertilizer next time. At this time there are no chemicals available for the home gardener (they would have an "H" after them in the article), and this rust will probably not kill the plants before harvest time next month.
I have had rust on my garlic for the past couple of years and the garlic bulbs are just fine to use. For next year, I suggest less dense plantings (maybe only 3 or 4 bulbs per pot), less nitrogen-rich fertilizer, and if you use the same pots, sterilize them with bleach and use new soil.
http://pnwhandbooks.stage.extension.oregonstate.edu/plantdisease/host-disease/garlic-allium-sativum-rust
As to your little black bugs, no, they are not related to the rust. They look like black aphids which can be removed with a spray of water or by hand. Simply wipe them off with a damp rag or tissue. If you do nothing, the ladybugs or lace wings may arrive to take care of them for you, but sometimes this can be a 2 week wait and you might not want to see them all that time.
Carry on with your curiosity and good luck with the garlic!
Wow! Thank you SO much for the great information! I feel so reassured and excited that I can improve the crop next season. Thank you for your time and advice!
