The approach of summer is a time of beauty, with flower gardens exhibiting all shades of color and texture. Even the various bark mulches that are used to shade the soil and retain moisture add greatly to this beauty. The drier weather seemingly has turned to a wetter pattern, which will stimulate fungal growth.
Occasionally during the summer, gardeners will notice a growth on their bark mulch which closely resembles -- should I say it -- dog vomit, and even in some cases scrambled eggs.
Hopefully you are not reading this article during a meal, but it is likely that these displays will become common in the coming days.
Some Extension offices have gardeners call after taking their dogs to the vet because their dogs 'must have eaten something bad' causing them to get sick. Other gardeners blame this problem on a neighbor because 'they don't keep their dogs in at night.'
It would be curious to know how many veterinarians prescribe medication to correct this condition and how many neighborhood problems have escalated due to 'sick' dogs. Gardeners trying to discover what type of plants could be causing their dog's stomach problem are often surprised when told this colorful, vomit-looking mass is a unique and fascinating fungus.
Known as slime mold, these fungi were once considered to be animals due to their creeping phase. They appear in several sizes and colors with no definite shape. Slime molds come in a variety of colors (basic brown, putrid salmon, off-off white, yellow, orange or brick red) and change color as they mature. Those in mulch change on a daily basis from a bright yellow netting, to a tan powder, to a dark brown dried blob.
Slime molds are like other fungi in that they reproduce by spores. When the spores are moistened, they germinate and give rise to microscopic amoeba-like organisms that either "flow" or swim in thin films of water. These organisms are larger than bacterial cells and will engulf and digest bacteria as they are encountered.
Eventually, several amoebae fuse, and when this happens, growth of the plasmodium begins. The plasmodium also preys upon bacteria and must have a moist substance on which to move. If conditions are favorable and food is plentiful, a circular plasmodium may become 2 feet or more in diameter. Most, however, are smaller than that and form a delicate net of brown, yellow, pink or white slime where they grow. The plasmodium moves "relatively rapidly," and may transverse a distance of several feet a day.
When substrates (logs, turf, mulch, etc.) dry and conditions for growth are no longer favorable, plasmodia aggregate to form spore-producing structures that resemble miniature puffballs. These puffballs may or may not be on stalks, their colors range from chocolate-brown to bluish grey to yellow to white, and their intricate beauty has attracted the interest of many naturalists. A new crop of spores forms within the structures, and the spores are blown away by the wind to eventually settle in new locations and start new colonies.
Preventative chemical treatments tried over the years have been found ineffective. Slime molds are more a curiosity or nuisance than a threat to gardens or lawns. Once a colony starts to form, allowing mulch to dry out, or using a garden or leaf rake in the affected area helps break up the colony and provides limited control. Like nature's other organisms, slime molds can be looked at for their colorful beauty and enjoyed as one enjoys a mass planting of dianthus or snapdragons.
This too is a matter of attitude!
Visit our website at www.extension.purdue.edu/putnam or you can contact the local Purdue Extension Office by calling 653-8411 for more information regarding this week's column topic or to RSVP for upcoming events. It is always best to call first to assure items are ready when you arrive and to RSVP for programs. While many publications are free, some do have a fee. All times listed are Eastern Time.
May 17: All remaining 4-H Livestock enrollment forms due to office
May 22: 2010 Tox-Away Day in Putnam County
June 1: State Fair Beef, Sheep, Swine, & Dairy Forms Due
June 3: Extension Homemakers Tour to Wick's Pie Factory
June 9-11: Home and Family Conference at Purdue
June 12: Putnam County Master Gardeners' Garden Tour
June 15: Greencastle Farmers Market opens
June 17-19: 2010 State Conference for Purdue Master Gardeners
July 1: State Fair Cat, Dog, Horse & Pony, Goat, Poultry, and Rabbit forms due