From the Garden: Two Classic Garden Pests -Slugs and Aphids

By Erin Breglia

Slugs! Aphids! The names alone bring a creepy-crawly feel­ing to mind, espe­cial­ly if these pests have been sab­o­tag­ing your gar­den! But rest assured, if we uti­lize appro­pri­ate ways to dis­cour­age them and under­stand the ben­e­fits they pro­vide in our envi­ron­ment, we can find ways to live togeth­er with­out bug­ging each other!

The slug is a soft-bod­ied mol­lusk rather than an insect. Its clump-like body moves along on its foot, and it secretes an ooz­ing trail when it moves. Unlike the sea mol­lusk, the slug does not require a shell for pro­tec­tion. Slugs must always stay moist to sur­vive so they love wet, dark areas. They can be found under­neath sur­faces, hid­ing in large wood chip mulch or at the base of plants. They are active at night so it can be dif­fi­cult to know if they are dam­ag­ing the gar­den. A quick trap of lay­ing card­board on bare ground around the base of plants and turn­ing it over each morn­ing to see if they have accu­mu­lat­ed can help. Scrap­ing the slugs off and remov­ing them from your gar­den can offer con­trol. The trap can be reset until the prob­lem sub­sides. Oth­er options include the appli­ca­tion of diatoma­ceous earth or crushed oys­ter shells around the base of plants. Both dam­age the soft body of the slug and will also deter them from enter­ing the area.

Aphids are anoth­er nui­sance that can wreak hav­oc in the gar­den. These true bugs have straw-like mouth­parts that they use to pierce and suck the flu­ids from plant leaves and flow­ers. Most abun­dant in spring, they can rapid­ly repro­duce and col­o­nize a plant, with the adult life cycle aver­ag­ing one month. They favor all sorts of plants and dam­age them very quick­ly, but as sum­mer tem­per­a­tures rise, their pop­u­la­tion decreas­es. The best way to con­trol them is to use a nat­ur­al insec­ti­ci­dal soap spray called Safer Soap. This solu­tion will con­trol aphids by pen­e­trat­ing their out­er lay­er and dry­ing them out with­out dam­ag­ing the plant or ben­e­fi­cial insects which feast on them as well.

Though slugs and aphids may look off-putting, they do offer ben­e­fits to the gar­den that should not be over­looked. Slugs are a food source for toads and birds and also cre­ate aer­a­tion in soils when tun­nel­ing. Aphids are an excel­lent food source for ben­e­fi­cial insects in the gar­den such as lady­bird bee­tles and lacewings. They also have an inter­est­ing rela­tion­ship with ants, which will pro­tect them from preda­tors in exchange for the sweet excre­tion they pro­duce called honeydew.

These rhythms of nature are in place to con­trol pop­u­la­tions and until out of bal­ance, things should be man­age­able. If envi­ron­men­tal fac­tors such as an abnor­mal abun­dance of rain occur, both of these pop­u­la­tions are like­ly to increase, but with some nat­ur­al prod­ucts and preda­tors and a lit­tle extra atten­tion a gar­den­er can rebal­ance the wheel with min­i­mal dam­age to the environment.


Summer 2018

Volume 36 , Number 3

Share this

The Latest from Landis

Aug 06, 2022

Landis Forest 5K - August 6, 2022

A record turnout! Click here to view all the great photos from this event, and... read more

Jun 10, 2022 | Anne Donnelly

Don't Overlook Your Reciprocal Admissions Privilege

A sometimes overlooked benefit of your Landis Arboretum membership is the American Horticultural Society Reciprocal... read more

May 29, 2022

Scenes From the Spring Plant Sale

Thanks to our many wonderful volunteers, plant consignors, vendors, and customers, the Landis Signature Spring... read more

May 28, 2022 | Fred Breglia, Executive Director

From the Director’s Desk: Q&A, Part III

In this last Q&A session, I am focusing on leaf color change during the... read more

May 28, 2022 | Erin McKenna Breglia, Landis Gardener

From the Garden: Milkweeds for Monarchs!

Many people enjoy seeing butterflies in our Landis gardens. especially the monarch butterfly, Danaus... read more

May 28, 2022 | Anita Sanchez

Life and Death on the Lawn

It’s a beautiful summer day. You’ve finished your stack of books from the Landis... read more

News Archive