My cucumber plants are dying

Asked August 18, 2017, 2:04 PM EDT

What could be wrong with my cucumber plants? They are from seed, "cucumber Muncher". They were doing fine until the hot spell 2 weeks ago. They had 2-3" fruit, blooming well and being polnated. A sudden die off of 2/3s of plants occured. The main root apears to have been stripped of little roots and skeletonized. What must I do to prevent this? I now have noticed a lot of milipedes attacking the roots of my onion plants. What can I use to control milipedes?

Columbia County Oregon

4 Responses

Thank you for using Ask an Expert. I’m sorry to hear about your problems with your cucumbers and onions.

Let’s begin with the onions. Millipedes are scavengers that eat dying and dead tissues. So, in this case, something damaged the onion roots before the millipedes arrived. Unfortunately it’s too late to do anything after the roots are dead. “Growing onions in home gardens” may provide clues you need. (

It will be very challenging to diagnose the cucumber problem. I can see from the image that they are in a container. Among the many questions that come to mind, and that need your answers, are these: 1) What size is the container? 2) Does the container have drain holes? 3) What is the container filled with? (Commercial potting mix? If your own mix, what are the components and how much of each?) 4) How often did you water? 5) How did you determine the plants needed more water? 6) What did you see when the plants first started failing?

Please send your answers to the above questions. Add anything else you think might be important. In the meantime, take a look at “Growing Cucumbers.” (

Also review “New urban gardeners grow in containers” ( and “Growing your own; a practical guide to gardening” (

The containertia in question is merely used to transport the dead plant to OSU agent office. The 7 cucumber plants were raised in a raised bed. They thrived until they attained fruit of 2 inch. Then severe wilt occured and intolerance to sun. Plants began to gradually die off.plenty of water.

Adult onions had very small and sparse roots. The millipedes are very plentiful under mulch used throughout garden. Most every thing else is thriving, except for the fluxation of temperature.

Thank you for the additional information and the images. Even though the plants were in the ground instead of a container, the same questions are important but directed, of course, at the planting bed. I need to know as much as you do. Please provide as many details as you can.

This has been a challenging summer for many vegetable gardeners. The excessively high temperatures, combined with the often lower-than-usual humidity, meant that plants wilted much more rapidly­­­, and more often, than during a typical summer. This year, either too much or too little water has been a leading cause of failing vegetables.

The roots on the cucumber are rotted. When did you dig it up? Was it when the plant was as shown in the 2nd image? Or a number of days later?

When you took the remains to the Extension office, did you speak with the agent? If yes, what did he say?