Fairy Ring Fungus, Norway Spruce, Frost Date
It is good to see the green grass growing after the cold and snow filled days of winter. It is always exciting when plants start waking up and growing after a long slumber. Just like plants, gardeners also wake up from the long winter slumber. I’ve included a few questions that I think will be of interest to you this week.
The first question was emailed to me by Becky. She wrote, “I have several large circles, perfectly round, of very green grass in my backyard. One is out in the open while the others are near trees. The grass inside the circles isn’t green, just looks like winter grass. I have looked on the internet but cannot find a fungus that matches this description. I fear I need to treat this right away. Do you have a suggestion?”
What Becky described is a very accurate description of fairy rings. Fairy rings are caused by a fungus. Fairy ring fungus lives like many saprophytic fungi, as it decomposes stuff that was once alive, like grass, roots, and wood. As the fungus decomposes, it releases the bound nutrients for the grass to take up. This extra nutrition helps the grass thrive where the fungus is actively growing. The fungus starts as a small area about a foot in diameter. However, once the dead organic matter is consumed by the fungus, it grows outward. As the fungus grows outward, it appears as a circle.
What should be done? There are two options. The first is to do nothing. The other option is to fertilize the lawn. This fungus is not harming the grass, but it is actually fertilizing the grass where the fungus is growing. The fungus is digesting the unstable organic material in the soil. To make the dark green circles go away, just fertilize the entire lawn. This will cause all the grass to grow, and the fungi will not be evident.
I should mention there are two other types of fairy ring fungus. One is a problem for golf course managers with bentgrass greens. This fungus does actually harm the turf, and it is the only one of the three types that warrants treatment. The third type of fairy ring fungus is only evident by the puffballs that emerge in the lawn. However, these puffballs are short lived, and I like mowing them with the lawn mower. Typically, these are seen later in the spring and early summer.
Several people have asked me the identity of the pictured evergreen. The tree has a unique overall shape and form.
On closer examination, you can see the needles are single, rather than in clusters of 2, 3, or 5 like many of our pine trees. Although hemlock trees have single needle arrangement, they are arranged in a flat plane, not whorled around the stem like this tree. When you see evergreens that have a needle arrangement like that pictured, think spruce. In this case, the size of the tree and shape of the cone indicate it is a norway spruce (Picea abies).
Norway spruce is a European tree that can grow from USDA hardiness zone 3 to 7.
Caldwell County is zone 7, so we are at the southern range of this tree. If you are interested in planting this tree in your landscape, realize the mature size of this tree is 100 feet tall and 50 feet wide at the base. Be sure to allow space for this tree to grow. Do not plant this tree near or under a powerline. This tree should only be planted where there is a large space.
Although lawns are greening up, pear trees are blooming, and forsythia (yellow bell) have turned yellow, don’t get too anxious. Our average last frost date is April 15. When the temperature drops and water turns to ice, interesting things can happen. If water freezes inside plant cells, it will kill the plant cells. This death could be just the bloom or tender part, or it could be the entire plant. When the ground is saturated and it freezes, this can cause problems too, but it can also be helpful.
The benefit of the ground freezing is it loosens the soil. The negative aspects are it may kill young seedlings by pushing them out of the ground. Attached is an impressive picture of frost heaving. Thanks to Phoebe Crosby for sharing this picture. She titled the picture “Fingers of Jack Frost”.
If you have a specific question, please contact the Caldwell Extension Center (828.757.1290) or visit our website at http://caldwell.ces.ncsu.edu to contact us. The Caldwell Extension Center exists as a partnership between NC State University and Caldwell County. Our mission is to share research based knowledge to improve the lives and profitability of Caldwell County farmers, citizens, and families.