Master Gardener – Search

Master Gardener

Virtual Help Desk

Get help straight from two Master Gardeners

Searching: Spider Sac in the garden

If you don't see the answer you're looking for, try submitting your question.

First | 1 | Last

Spider Sac on plant

    Date Posted: Sun, Oct 10 - 2:59 pm

    Question

  • I have several long white strings of balls that looks like a moth cocoon or something from a plant in my backyard. Any idea what it is and if I should take it down? I wanted to submit a photo but it doesn't look like there's an option to do that. But they're about 2 in long and the balls look to be about the size of a very small pea and there's probably 8 or 10 of them hanging vertically in a string.
  • Answer

  • Good morning! Thank you for your question. You have provided a very good description, and without actually seeing a picture, I'm guessing what you are seeing is a spider sac. Spider sacs can come in a variety of sizes and can range in color from white to yellowish to brown, and the individual sacs will be about the size of the spider which produced it. They typically appear as a thick netting of spider silk with multiple eggs inside, and can be found on plants. Some spiders make just one egg sac and others will make several small ones. You don't want to directly disturb a spider egg sac which has potentially viable eggs, or you risk releasing hundreds of small spiders. The best way to get rid of it is to first spray it with a mixture of 1/2 bleach and 1/2 water to kill the spiders/eggs. Use protective gloves and long sleeves. Once you spray it, you can then use an elongated tool to remove the sac (or you could cut that branch or leaves to which the sac is appended), and place in a plastic bag, tie it tightly, and throw it in the trash. Or you may choose to just leave the spider sac since it is outdoors, as it will not directly harm the plant, and may have some beneficial use in the garden (of course this depends on the type of spider). While spiders will not directly harm the plant, they do feed on both harmful as well as beneficial insects in the garden (including bees, butterflies, ladybugs). If what you have is in fact a spider sac, I would recommend getting rid of it to be on the safe side. Hope this helps, and happy gardening!