I Ain’t Afraid of No Slime Mold

I Ain’t Afraid of No Slime Mold

The plasmodium of Fuligo septica slime mold consuming bacteria and fungi inside the office worm bin. Photo by Molly Jameson.

Just when we thought we had our Leon County Extension vermicompost bins all figured out for recycling office food waste with the aid of worms…aliens invaded. I instinctively started looking all over for my “Ghostbusters” proton gun and backpack – but when they didn’t turn up, I decided to retreat and do a little research.

Fuligo septica moves as a mass of protoplasm about a millimeter an hour. Photo by Molly Jameson.

A mesmerizing bright yellow substance had taken over the entire top of the office worm bin, and when the lid was lifted, the yellow ooze was streaming down the inside of the lid and into the bin. Long, squiggly zig zags seemed to be engulfing nearly all the contents within the worm bin.

Unlike Ray Stantz’s reaction when he first meets Slimer devouring the room-service leftovers in the hotel hallway in the original “Ghostbusters,” we were all a little taken aback by our surprise intruder.

“Oh my! Will it kill our worms? Is it toxic? Where did it come from?”

Turns out our slimy yellow visitor was Fuligo septica; a species otherwise known as – and here’s hoping you’re not eating – dog vomit slime mold. A fitting name, indeed. To our amazement, Fuligo septica is not actually a mold (aka: fungus). Nor is it a plant, animal, or bacteria. It is actually a plastid, in the kingdom Protista and class Myxogastria, whose wind- or insect-spread spores converge and divide into a singular giant cell containing millions of nuclei, known as a plasmodium. These individuals come together to form a larger plasmodium and move as a mass of protoplasm, about a millimeter per hour, to feed on microorganisms living in decaying plant material.

I know what you’re thinking…this smattering of scientific terms has you right back in high school science class, and you’re feeling a bit woozy. But really – who needs science fiction movies like “Ghostbusters” when we have scientifically-explained neon slime molds all around us?

After a few days, Fuligo septica transforms into a pillow-like fruiting body in preparation for spore dispersal. Photo by Molly Jameson.

Besides the potential of Fuligo septica spores to be an allergen to those who are susceptible, this surprisingly common slime mold is not toxic to people, plants, or animals. It can be found on rotting bark and forest floors in nature – or on wood mulch in urban areas – normally when conditions are moist. The microorganisms the slime mold consumes are mainly bacteria and fungi, which are also very much present in the decaying food scraps and coffee grounds within a worm bin. And although Fuligo septica is harmless to people, it needs to watch out for us, as it is actually edible! Appropriately, another name for dog vomit slime mold is scrambled egg slime, as indigenous people in some areas of Mexico have collected the mold and scrambled it like eggs. Breakfast anyone?

Although real-life slime molds give Slimer a run for his money, the plasmodium blob of Fuligo septica will not stay its striking yellow amorphous shape for long. After a few days, it transforms into a pillow-like aethalium – a spore-bearing fruiting body like that of a mushroom – then degrades, darkens to a pinkish tan color, and finally releases its spores to start anew when conditions are right.

As the slime mold degrades, it darkens to a pinkish tan color, and releases its spores into the air. Photo by Molly Jameson.

Slime molds have stood the test of time, as analyses of their DNA has revealed they’ve been on Earth approximately a billion years! For reference, that’s hundreds of millions of years before plants or animals. And it’s a good thing Fuligo septica is here, because some of its characteristics has shown a lot of potential to be helpful, including as antibiotics, an ability to fight cancer cells, as antimicrobials, and environmental site remediation due to its ability to hyper-accumulate toxic heavy metals, such as zinc, and convert them to inactive forms. Scientists have discovered it’s the same yellow pigment that gives Fuligo septica its striking color that also forms a chelate with the heavy metals.

So, if you’re walking through a forest, down a path of mulch, or tending to your worm bin and come across this eye-catching, bright-yellow blobby creature, let this plasmodium do its thing. Probably better to scramble some actual eggs, lest your guests be squeamish.

Be Proactive to Ward Off Armillaria Root Rot

Be Proactive to Ward Off Armillaria Root Rot

Recently, an Extension Agent in the Florida Panhandle received a picture of some mushrooms popping up in a client’s garden.  These particular mushrooms were in a spot where leftover mushroom compost had been dumped.  The compost was previously used to grow oyster mushrooms and the client was hopeful that she had more oyster mushrooms growing in her yard.  Unfortunately, the lab results came back stating the mushrooms in question were Armillaria spp.

Armillaria spp.

Armillaria spp. in the garden. Photo Credit: University of Florida/IFAS Extension.

Armillaria spp. cause root rot of trees and shrubs throughout the world.  The fungus infects the roots and bases of trees, causing them to rot and eventually die.  Some species of Armillaria are primary pathogens that attack and kill plants, but most are opportunistic pathogens that are attracted to unhealthy or stressed plants.  Fruiting structures of the fungi can be recognized by the clusters of yellow to brown-colored mushrooms that emerge during wet conditions.  However, the mushroom caps sometimes never form and the plant material needs to be inspected more thoroughly to find the disease culprit.  Infected plants may have wilted branches, branch dieback, and stunted growth and should be removed and replaced with resistant species.

White mycelial fan under the bark of a root.

White mycelial fan under the bark of a root infected with Armillaria tabescens. Photo Credit: Ed Barnard

Management – The best method for controlling Armillaria root rot is with proper plant installation and maintenance.  Planting plant material at the proper depth will allow the roots to breathe and reduce the opportunity for the roots to rot.  Pruning tools should be sanitized between plant material.  Proper irrigation and fertilization will also reduce the risk of plant disease and root rot.  Lastly, you can choose to plant a diverse landscape with resistant species.

For more information on Armillaria root rot and a comprehensive list of resistant species, please view the EDIS publication:  Armillaria Root Rot

Low Maintenance Ground Cover for Hot, Dry Sites

Low Maintenance Ground Cover for Hot, Dry Sites

Shore juniper forms a thick groundcover and tolerates hot, dry sites. Photo: J_McConnell, UF/IFAS

We all know that when you have bare ground in Florida, eventually something unwanted moves in or the soil moves out. To avoid either of these negative outcomes, a good practice is to grow robust vegetative groundcovers, especially if the soil slopes and is at high risk of eroding. Turfgrass is one option, but what if you don’t enjoy caring for a lawn or the site is difficult to maintain or even unsafe to mow? An often overlooked option in our area is Shore Juniper Juniperus conferta.

Although some people find this plant less than exciting, its easy to explain why it can be a good option in certain situations.

  • Easy to find at nurseries
  • Inexpensive
  • Low water requirements once established (you’ll need to turn the irrigation off on these!)
  • Salt tolerant
  • Evergreen
  • Cold tolerant
  • Low, spreading growth habit (won’t block view)
  • Do not require pruning (junipers cannot tolerate heavy pruning!)

A common cultivar of shore juniper is Blue Pacific Juniper which grows to be about one foot tall but spreads two to three feet wide. The new foliage has a blue cast that gives it the common name. It creeps along the ground and will provide good ground cover to sloping sites. This plant should be planted on 3 foot centers so they have room to expand without crowding. Plant in well-drained soil and apply two inches of mulch on bare soil between plants to reduce weeds while the plants are filling in. Only water until established, then stop automated irrigation and only water as needed. Read more at Establishing Shrubs Florida Landscapes.

A Ghost in the Woods

A Ghost in the Woods

Ghost plant/Indian pipes emerging from the ground. Photo credit: Carol Lord, UF IFAS Extension

Imagine you are enjoying perfect fall weather on a hike with your family, when suddenly you come upon a ghost. Translucent white, small and creeping out of the ground behind a tree, you stop and look closer to figure out what it is you’ve just seen. In such an environment, the “ghost” you might come across is the perennial wildflower known as the ghost plant (Monotropa uniflora, also known as Indian pipe). Maybe it’s not the same spirit from the creepy story during last night’s campfire, but it’s quite unexpected, nonetheless. The plant is an unusual shade of white because it does not photosynthesize like most plants, and therefore does not create cholorophyll needed for green leaves.

In deeply shaded forests, a thick layer of fallen leaves, dead branches, and even decaying animals forms a thick mulch around tree bases. This humus layer is warm and holds moisture, creating the perfect environment for mushrooms and other fungi to grow. Because there is very little sunlight filtering down to the forest floor, the ghost flower plant adapted to this shady, wet environment by parasitizing the fungi growing in the woods. Ghost plants and their close relatives are known as mycotrophs (myco: fungus, troph: feeding).

Ghost plant in bloom at Naval Live Oaks reservation in Gulf Breeze, Florida. Photo credit: Shelley W. Johnson

These plants were once called saprophytes (sapro: rotten, phyte: plant), with the assumption that they fed directly on decaying matter in the same way as fungi. They even look like mushrooms when emerging from the soil. However, research has shown the relationship is much more complex. While many trees have symbiotic relationships with fungi living among their root systems, the mycotrophs actually capitalize on that relationship, tapping into in the flow of carbon between trees and fungi and taking their nutrients.

Mycotrophs grow throughout the United States except in the southwest and Rockies, although they are a somewhat rare find. The ghost plant is mostly a translucent shade of white, but has some pale pink and black spots. The flower points down when it emerges (looking like its “pipe” nickname) but opens up and releases seed as it matures. They are usually found in a cluster of several blooms.

The next time you explore the forests around you, look down—you just might see a ghost!

Fig Leaves Dropping Early?

Hopefully, by this time of year, most north Florida gardeners have harvested their figs and are enjoying fig preserves or fig bars. But if you’ve noticed your fig leaves dropping a little early, it may be a sign of the fungal disease Fig Rust (Cerotelium fici).

Figs are a great fruit tree for the north Florida home garden. Not only do they provide a tasty reward (if you can keep the birds and squirrels away), but they are fairly easy to maintain and are bothered by relatively few pests and diseases. One of the few diseases that can be common, however, is fig rust, especially when conditions are favorable. In the case of fig rust, a fungus, warm humid weather is what it likes and well, we have plenty of that.

Figs are a great fruit tree for North Florida. Credit: Mary Derrick, UF/IFAS.

 

The first signs of the fig rust disease are small yellow to yellow-green spots/lesions on the upper surface of the leaf that turn a reddish-brown color as they get larger. A heavy infestation causes the leaves to turn yellow and drop early. While fig rust does not injure the fruit, repeat occurrences of premature leaf drop can adversely affect the overall health of the tree, resulting in yield loss. Another concern is that if the leaves drop too early, the tree will flush out with new growth heading into winter. This new growth can be injured by early freezes and cause a loss of fruit the following season.

 

Fig rust on leaves. Credit: UF/IFAS.

 

What can you do to prevent and/or cure fig rust? Unfortunately, once you see the yellowish-green/reddish-brown spots on the leaves, it’s too late to provide any control. As always, proper cultural practices can help. Pruning the tree to provide adequate airflow keeps the leaves as dry as possible during our humid summers. Remember to prune fig trees in Florida after fruit harvest, not in the dormant season, since fruit is borne on previous year’s growth. Another cultural control to prevent fig rust is to rake diseased leaves out from under the tree. The fungal spores in the fallen leaf litter pass the disease on to next year’s leaves. Other cultural controls include providing adequate moisture and placing a healthy dose of mulch around the tree. Figs require minimal fertilizer. Using a general complete fertilizer with micronutrients (such as a 10-10-10), young trees should receive 1 cup (1/2 pound) and mature trees 4-8 cups (2-4 pounds) per year.

There are currently no chemical controls approved for fig rust in Florida. The classic Bordeaux mix is recommended by various authors to be used as a preventative fungicide during the dormant season, before the lesions appear on the leaves. The Bordeaux mixture is a mix of copper sulfate, lime, and water in a 1:1:10 ratio and is considered an organic pesticide.  This mix has been used since the late 19th century and was discovered by accident after botanists and farmers realized that grapevines sprayed with the mix to deter theft had less fungal problems. As with any pesticide, be cautious when using. Overuse of copper-based fungicides can cause copper to build up in soils, leading to potential issues to plant and human health.

While figs are generally worry free for our area, fig rust is one disease to be on the lookout for. Good gardening practices can reduce the occurrence of this disease and ensure a bountiful harvest. For questions on growing figs or about the fig rust disease, visit the UF/IFAS EDIS website – edis.ifas.ufl.edu – or contact your local Extension office.

Reduce 100 Bags of Fall Leaves to Ten

Reduce 100 Bags of Fall Leaves to Ten

Image Credit: Matthew Orwat, UF / IFAS ExtensionBillions of leaves blanket the fall landscape and are bagged by hundreds of homeowners to be placed curbside for local trash pick-up.

Many of these leaves could be easily turned into valuable mulch or compost.

Why do all those fall leaves end up in bags to be discarded?

It’s probably because the homeowner is overwhelmed by the volume. For instance, one resident reported raking more than 100 large bags of leaves from his half-acre property. One large oak tree can contain over 250,000 leaves!

Bagged and discarded leaves could become a quality mulch or could be composted.

Homeowners have tools for reducing 100 bags of leaves to 10 in their own backyards.

Shredding and composting can reduce leaf volume by 90 percent and provides a manageable quantity of valuable mulch and an excellent organic source for composting and converting into rich humus to improve garden soil.

Shredded leaves stay seated better on the landscape than whole leaves. They also do a better job of holding moisture in the soil and don’t mat down like whole leaves.

But how do you shred leaves if you don’t have a costly leaf shredder?

All you need is a lawn mower, a little extra time and a concern for the environment. Just put the leaves on the lawn in rows around three feet wide and two feet deep.

Then, with the lawn mower at the highest wheel setting, run over the pile. If the mower has a bag attachment, collecting shredded leaves is a neat and easy task.

Without a bag, the easiest way to collect them is to put a 9-by-12-foot drop cloth parallel to the row of leaves. Then, by running the mower in one direction so the leaves are discharged onto the cloth, cleanup is easier.

Throw the shredded leaves in the compost pile to cut the volume by another 50 percent.

Shredded leaves will shrink within a week and compost faster than whole leaves.

 

To compost dry leaves, add water, a little garden soil and a cup of garden fertilizer.

 

For more information on gardening and landscaping, contact the UF/IFAS Extension Office in your County.