Diagnosing Marigold Problems

 

                           Photo taken by juggzy_malone

TheGardenLady received this question from Liz on her “Caring for Marigolds” post.

I am growing marigolds in tall (3″) pots in a very sunny location of my backyard. In the pots I have also planted white flowering bacopa, ivy and a browny spikey grass (not sure of the name).  Everything in the pots were growing well for a few weeks until recently when I noticed that the bacopa stopped flowering and the foliage and flowers of  the marigolds had turned into a daily meal for something.  I’ve checked in the soil, and around the marigolds both in the day and in the evening but can ft locate any insects other than the one lonely earwig.  I have read that the only pests that will feast on marigolds are slugs but I can’t find any in/around my pots. Can you offer any information on what may be causing my frustrations???

You write that you created a mixed pot of plants that includes bacopa and marigolds. Was it your idea of putting these plants together? TheGardenLady would not recommend combining marigold and bacopa in one pot. My understanding is that bacopa will stop flowering with severe drying out. Bacopa likes part sun. But marigolds like full sun and don’t need as frequent watering.

Not knowing the kind of ivy you have or what the grass is that you have, I cannot tell you the proper culture for those two plants.

When mixing plants in a pot, one has to be sure that the needs of each plant is similar to the needs of each of the other plants you put with it. Check out potted plant combinations in good nurseries and plant similar mixtures in your own pots.

Marigold plants have fewer problems than most plants, but they do have problems. A list of problems of marigold plants can be found here. 

TheGardenLady can not see your pot problem so it is difficult to diagnose what is getting at your marigold plants. But TheGardenLady thinks your marigold problem is due to earwigs. They are nocturnal so one wouldn’t find many during the day. Marigolds are a favorite target of earwigs. Earwigs eat marigold leaves
and flower petal margins. Reduce decaying organic matter such as fallen leaves and mulch. Earwigs love mulch. Try shaking the plants to be sure the earwigs are not hiding under any of the leaves in the pot. Then prune away damaged marigold leaf and petal areas. Deadheading the marigold flowers will force more flowers to bloom. Earwigs hide in cracks and crevices during the day so you can trap earwigs overnight in rolled newspapers. In the daytime unroll the newspaper and drop any earwigs into a pot of soapy water. Put the flower pot under a birdhouse and hope that birds will eat the earwigs.

                          Photo taken by spanglemaker

As you read, slugs can be another problem with marigolds. If you look for them, you probably wouldn’t see the slugs in the daytime because they can’t tolerate the sun’s rays. So you should check the plants with a flashlight at night or go look on a dreary rainy day.  If you do have slugs you might find the slug eggs in the soil. Then again if there are slugs but you don’t see them, most likely you will see a slimy, shiny trail left by the slug as it crawls up the pot.

Clean up anything around the pot that the slugs could hide under. Some recommend putting a wooden plank next to the pot which, if there are slugs, they will crawl under to hide. You can step on the plank and squash them before turning it over.

There there ARE some things to do to prevent slugs or, if they are there, to get rid of slugs. (There are slug baits, but some of them are really very toxic. Some of the chemicals can kill pets. TheGardenLady wouldn’t suggest anything toxic. ) If you can get some copper tape, put it around the edge of the pot, snails don’t
like to crawl over it. However, if there is any overhanging plant branch, the slugs can climb on the branch and get to the plants. So be sure that the overhanging plant branches are removed.

Snails don’t like sharp things to slide over so one can sprinkle sawdust, builders sand (no salt), ashes or lime around the edge of the soil near the pot rim. If kept dry, these items make an irritating, drying surface that slugs don’t like to crawl over. Again be sure there are no overhanging plant branches for the slugs to use to avoid the sharp things you put in the pot.

If you see slugs, you can use disposable gloves to “hand pick” slugs at night or when it is cool and wet. Collect them in a jar half filled with soapy water.

Everyone seems to know how slugs like beer. Buy some cheap beer or mix some fruit juice with instant yeast, put the liquid in a container and sink it in the soil of the flower pot or put it near the pot so that the slugs can get in to drink but can’t get out and will drown. Replace beer or juice frequently and discard the old stuff with the dead slugs.