Dandelions form “blow balls” to disperse seeds by wind. Photo by Joseph OBrien, USDA Forest Service, Bugwood.org.
A Second Look at Dandelions
Many of us have memories of spotting a dandelion as a child and immediately gravitating toward it, eager to hold it up by the stem and blow with all our might. If all the puffs of white disappeared, we were sure the dandelion would grant us our wish.
Dandelion flowers, leaves, and roots are all edible and contain many vitamins, minerals, and antioxidants. Photo by Bruce Ackley, The Ohio State University, Bugwood.org.
As an adult, spotting a dandelion may still remind you of the good ole days, but when they begin to encroach upon your lawn or garden, they are likely to be seen less as a friend and more as a foe.
Perhaps the reason they give landscapers headaches is because dandelions thrive in many conditions. They have the ability to grow in the sun and in the shade, and they do well in both disturbed and undisturbed soils. Once more, they thrive in moist environments, and because they are perennials capable of developing long taproots, they also do well in dry environments. A dandelion taproot can grow as deep as three feet in search of water.
Dandelions are an important early season nectar and pollen source for bees, such as for this carpenter bee. Photo by Ansel Oommen, Bugwood.org.
Although the common dandelion (Taraxacum officinale) is native to Eurasia, it is naturalized to North America and is believed to have arrived with European settlers in the 1600s. At first glance, you may wonder why colonists bothered to transport such a small yellow flower so far. As it turns out, dandelion flowers, leaves, and taproots are all edible, serving as great sources of fiber and vitamins A, C, and K. Additionally, they are a source of antioxidants, such as beta-carotene, and minerals such as iron, calcium, potassium, and magnesium. Coupled with their ability to thrive in many conditions, you can see why dandelions made a great edition to colonial herb gardens.
Since their arrival in North America, dandelions have become an important early season nectar and pollen source for bees, and they help support both the larval and mature stages of some species of butterflies and moths. Additionally, dandelions can be a food source for wildlife, such as white-tailed deer, quail, wild turkeys, and rabbits.
A single dandelion “flower” can have more than 100 florets that each develop into a seed-like fruit that has a parachute-like pappus that can carry the seed up to five miles away. Photo by Joseph Berger, Bugwood.org.
A member of the Aster family, dandelions are related to lettuce, artichokes, and sunflowers. When you look at a dandelion flower, you are actually seeing many, many tiny flowers, called florets. A single dandelion “flower” can have more than 100 florets that open in the morning and typically close at night. After a few days, the florets remain closed and each develops a seed-like fruit atop a hollow flower stalk. As the seeds mature, the flower stalk elongates up to two feet high and a tall standing “blow ball” forms. Each ball is comprised of many seeds, each attached to a tuft of bristles, or pappus, that can use the wind to parachute the seed up to five miles away.
So next time you notice a patch of dandelions standing tall on the landscape, put down your herbicide and take a closer look. Observe the visits from hungry bees and butterflies, perhaps pluck some fresh flower petals to add to your morning pancakes, and then pick out your favorite puff of white and make a wish.
Attacking mosquitos are spoilers for our outdoor activity interests this time of year. Hurricanes and other storm events tend to be a catalyst that increases these populations. Not only are mosquitos a nuisance, but they are carriers of several diseases. But, there are ways to control these annoying pests and get some relief.
Mosquito populations can be divided into two categories: floodwater mosquitoes and standing water mosquitoes.
Floodwater mosquitoes need water to lay their eggs, and the eggs also need to dry out before hatching during a storm event. Moist areas like pastures, planting furrows, salt marshes and swales are prime habitat. If you look close, the eggs can be found in cracks in the soil. Again, stormy rains and surge act as a catalyst for these eggs to hatch. So, what is the approximate estimate of mosquito eggs per acre in floodwater habitat in Florida? Scientist estimate 700,000 to 1.3 million eggs per acre. And yes, that’s per acre. Unfortunately, small scale efforts to reduce standing water around properties have little effect on control.
Figure 1. Standing water mosquito and eggs (Culex quinquefasciatus).
Credit: S. McCann, UF/IFAS/FMEL.
On the other side of the coin, standing water mosquitos need,…you guessed it, standing water to lay their eggs. These mosquito eggs cannot withstand drying out, therefore cannot hatch into larva. Females lay eggs on the surface of water with a hatching time of around 24 hours. The larva to pupae to adult stage happens quickly in mosquitoes, and the thirst for blood is not far behind. After a female finds a blood source, the cycle starts all over again. Only the females have biting mouth parts. Both male and female mosquitoes feed on the nectar of flowers. It’s the female mosquitoes that usually need a blood meal to insure mature eggs.The combination of the two groups of mosquitoes provide for a double whammy put in place by a storm. When dry areas flood, floodwater mosquito eggs hatch. When floodwater has nowhere to go, standing water mosquitoes have an abundance of places to lay eggs.
Unfortunately, some diseases can be transmitted by mosquitoes, such as west nile virus, eastern equine encephalitis and even heart worms in dogs. So, what can be done to combat these pests around your property? Reducing the amount of standing water helps dramatically, especially, dumping water holding containers. Cleaning debris from rain gutters too, can help as water can collect in blocked gutters. Mineral or cooking oil can be added to standing water and rain collection devices, as the oil forms a thin film on the surface of the water which causes larvae and pupae to drown. This is also a good control method with plant containers that collect water. Mosquito biological controls, like Bt (Bacillus thuringiensis) are helpful and will not harm pets or livestock. These products can be used in fish habitats, animal water troughs, bird baths, rain barrels, roof gutters and tree holes, just to name some. Please read precautionary statements and manufacturer application directions before use. Rain gardens are also very beneficial in suppressing standing water. If you have an area of your property that is known for water holding capacity, be sure to plant water loving plants in that area.
For more information please contact your local county extension office.
Supporting information for this article can be found in the UF/IFAS EDIS publication: “Hurricanes and Mosquitos” by C. Roxanne Connelly: https://edis.ifas.ufl.edu/pdffiles/IN/IN53500.pdf
UF/IFAS Extension is an Equal Opportunity Institution.