Overnight Garden Surprise!

Here is a test for all you gardeners. What do you get when you combine warm, wet weather with organic mulch?  Give up?  Well, you get an almost overnight surprise known as ’dog vomit’ fungus.  At first glance it looks like Fido had a stomach problem and your flower bed was convenient.  I put the photo at the bottom this time so readers would not be grossed out and fail to re the information.

The ‘dog vomit’ fungus is not a fungus, but a slime mold.  There are lots of different slime molds.  It is harmless to people, pets, and plants. In fact, it is edible. Native people in some parts of Mexico gather it and scramble it like eggs. They call this dish "caca de luna."   The translation is an even more entertaining name than dog vomit slime mold.

‘Dog vomit’ slime mold usually appears in late spring or summer following soaking rains. This year it is extra early due to the current weather conditions. The slime mold is usually found growing in mulched areas near homes and office buildings, but can appear in forested areas as well.

The color of this wonderful mold is often bright yellow, and in some instances, sickly orange or tan. This colorful growth occurs when the mold is beginning its fruiting stage. It can appear seemingly overnight causing some people to wonder what it is and how it got there. Therefore, you can see how this mold got its common name – blaming it on the dog.

There is no way to prevent slime molds; the spores are all over the place, just waiting for the right conditions to become active. If the appearance of a slime mold in your garden offends you, break it up by raking out the mulch or blasting it with the hose.

This web-site (http://waynesword.palomar.edu/slime1.htm) has some interesting photos of this slime mold near the bottom of the page.

So, now that you know all this you will not be surprised by the almost overnight appearance of this slime mold.  But I do not recommend eating it.

Dog vomit slime mold

Dog vomit slime mold

Moss Control in the Lawn

The mild, wet winter has been the ideal growing conditions for moss to grow in the landscape.  Some people like moss but most would prefer to have grass groing where the moss is.

Infestations of moss in turf is associated with unfavorable conditions for growing dense, healthy turf. Physical or chemical removal of moss will only be temporary unless growing conditions are improved.

Mosses are green plants with tiny leaves arising from all sides of a central axis. Mosses may grow prostrate or erect. They typically form a thick green mat at the soil surface. Conditions favoring the growth of mosses include poorly drained soils, low fertility and/or with low soil pH, soil compaction, overly wet soils, and excessive thatch or a combination of these factors that add to thin or weak turf. Mosses are very competitive in cool, moist, shaded locations, such as the north side of buildings and wooded areas.

The following practices will help prevent or control moss and algae:

• Plant shade-tolerant grasses.
• Conduct a soil test to determine proper lime and fertilizer needs. Liming will reduce soil acidity. Proper fertilization will enhance turf density and aid in preventing weed encroachment.
• Avoid excessive watering and improve irrigation scheduling.
• Aerify compacted soils.
• Increase air movement and light penetration in shaded areas by removing unnecessary undergrowth and pruning tree limbs.
• Improve drainage.

Copper sulfate, ferrous sulfate, and other commercially prepared moss and algae control products can be applied to help chemically reduce moss and algae but will only be temporary if the above cultural practices are not incorporated.

Pest Alert: Aphids on River Birch

Aphids on river birch

   Every spring about this time the new leaves on river birch trees become a magnet for aphids.  The aphids start accumulating on the tiny leaves as they emerge and quickly cause them to be crinkly and distorted.

   As to whether you need to treat the tree for the aphids depends on how many leaves are infested and how badly they look. Chemicals that will control aphids include acephate, azadirachtin, imidacloprid, malathion, dinotefuran, insecticidal soap, pyrethrins + canola oil. 

   Soil drench treatments with imidacloprid can provide effective, long-term control of aphids, but such treatments are slow acting and must be applied before heavy infestations develop.

 I rarely treat my river birch for the aphids.  Usually lady bugs will find them and I end up with a ladybug nursery!

River birch trees grow quickly and by late spring the damaged leaves have fallen off.

The Smell of Spring

Wild Garlic

The spring season greets us with a variety of sensory stimulations.  We see plants put forth their new leaves.  Flowers arouse us with a burst of color.  Birds issue their mating call.  Our thoughts of garden-fresh fruits and vegetables make our mouth water.  Often, however,  these pleasant reveries are quashed by the piercing odor of freshly mowed wild garlic and wild onion.

Wild garlic and its closely related companion, wild onion, are a serious perennial weed problem in home lawns.  These weeds are unwelcome eyesores in normally dormant lawns. 

The weeds cause nearly identical problems, and their names are used interchangeably.  There are some important differences in the two weeds, however.  Wild garlic has nearly round, hollow stems, whereas wild onion has flat, solid leaves.  Another distinguishing characteristic of wild garlic, that is usually only seen in the south, is the formation of aerial bulblets.  These aerial bulblets are smaller versions of the underground bulbs.  The underground bulb is a miniature version comprised of "cloves" like the domesticated version.  The bulb of the wild onion resembles a small onion.

The leaves and bulbs of both species can be used for cooking to impart flavor to bland foods.  They can serve as a replacement for the store-bought version.  Wild garlic may be a little strong for some people's taste buds, however.  Caution: To prevent possible poisoning from weeds that resemble wild garlic and onion, eat plants only if they have an onion-like odor. 

An interesting historical note is that the name for the city "Chicago" was taken from the Indian word "shikato" meaning ‘place where wild onions are strong-smelling.’

          When you are mowing the lawn in the spring and are engulfed with the smell of onions, just think of it as preparing a giant salad.  Maybe if you can convince your neighbors that these weeds are good to eat, they will come and mow your lawn for you just to get free garlic! 

         If you do not like to eat wild garlic (or onions) then it is time now to take action to control it.  Wild garlic and wild onions are difficult to control due to their cylinder shaped waxy leaves and large storage bulbs below ground.  Therefore, to get the best bang from a post-emerge herbicide application the herbicide needs to be applied while the wild garlic is actively growing and has tender tall leaves that have not been cut off with the lawn mower.  The best opportunity for controlling this troublesome weed is while your lawn is still dormant. Particularly for centipede and St. Augustine lawns that are more sensitive to many post-emerge herbicides.

          Recommended herbicides for homeowners that have good to excellent activity on wild garlic include imazaquin and the three-way combination herbicides such as 2,4-D, MCPP, and dicamba, Always read product labels carefully for safety to turf species and use rates.  And NEVER eat weeds that have been treated with a pesticide.

Stop Sticker Problems Now!

Spurweed or lawn burweed

   Every June people call about sticker weeds in their yards and what can they spray. I tell them: Sorry, it’s too late. This weed is lawn burweed (also called spurweed), but is more commonly called sticker weed due to the cluster of tiny seeds with spines on it. At maturity these seeds stick into tender flesh of bare feet, knees, hands, or whatever parts of the body that may come in contact with them.


   Lawn burweed is a low-growing, freely branched winter annual having leaves similar in appearance to tiny carrot leaves. This weed usually germinates in the early fall months, and remains very small, and inconspicuous in the lawn over the winter. As temperatures warm in the spring, it grows rapidly, flowers, and forms seed with a small spur or spine in the leaf axil junction.


   If you did not apply a preemergent herbicide this past fall to control winter annual weeds, and you had lawn burweed in your lawn last summer, then you most likely will have them again this year.

   But there is something you can do now. The trick to eliminating the spiny sticker problem is to control the weed before the spur is formed. If you wait to control the weed after the spur is formed, you can kill the plant, but the spiny sticker will still be there waiting for unsuspecting bare feet or hands.


   To control this weed in lawns, (that have not been over-seeded with a cool season grass) several herbicides are recommended. The ideal time to apply is from December to March, preferably on days with temperatures of 60 degrees F or warmer. The earlier in the season you apply the weed-killer, the easier this weed is to control.


   The following homeowner-labeled herbicides will control this weed and numerous other winter weeds. Choose one of them and mix it at the recommended rate in one gallon of water and spray over a 1000 square feet area: Atrazine @ 1.5 ounces, Weed B Gone @ 3 ounces, Ferti-Lome Weed Free Zone @ 1.5 ounces, 2,4D @ 1.5 ounces, Bayer Advanced Southern Weed killer @ 2 ounces, Trimec @ 2 ounces, or Spectracide Weedstop 2 @ 2 ounces.

   If the clumps have gotten large or the weather is too cool, two applications might be necessary. Wait 10 – 14 days after the first application to make the second one. Do not apply these herbicides around the drip-line of trees or in flowerbeds.


   Timely application of one of these herbicides will eliminate or greatly reduce this ‘sticky’ problem. You can be better prepared next year if you apply a preemergent weed killer next October. Contact your local extension office for a copy of P1322 Establish and Manage Your Home Lawn that contains a list of preemergent herbicides to control this weed.