Asparagus Bugs

Asked June 3, 2020, 5:15 PM EDT

Hi , I started preparing my Asparagus beds in the Spring of 2018.and let them grow without harvesting the whole growing season. We composted and fertilizied in the spring mid summer and the fall. Year two 2019 we once agian did not harvest any of the spears even though we were very tempted Composted and fertilized spring ,midsummer and fall. Year 2020 we stated harvesting and enjoying our Asparagus.........................out of thirty plants totaling 4-5 dozen all together............................I started seeing some plants that looked like the were sriveling and dying. We noticed l black and red beetles with white spots attacking the ferns and asparagus spear heads. We caught ,and deposited a few hundred in a container of soap and water.. they had left larvae on the branches. Its a loosing battles....................They have destroyed most of the plants.........................Catching all those little devils is a near impossible task We cut all the Asparagus plants down and deposited all the, plants, beetles and larvae in a black trash bag................moved them away from the garden. Any Ideas on how to salvage the Asparagus beds........................................................It now looks like and empty vegetable bed, Your solution will be greatly appreciated................( We missthe taste of our fresh Asparagus already )

Baltimore County Maryland

1 Response

Hi- sorry to hear about the infestation. Cutting down and removing all foliage now is a good way to disrupt the pest life cycle. It will weaken your plants to some degree but if they were healthy and the soil is fertile (top dress the bed with an inch of compost) you will see some new fern growth this year and they should come back strong next year.

Here is an excellent web page on the two asparagus beetle species and how to manage them:
https://extension.umn.edu/yard-and-garden-insects/asparagus-beetles#using-pesticides-88313

Based on the high population of beetles you should consider applying an insecticide. Organic and synthetic options are given. Most, if not all of the suggested insecticides are labeled for use in MD.
Jon