I am sure you have seen the memes on social media; Dandelions are the first food for bees. “Don’t pick dandelions and save the honey bee”. How important are these dandelions to bees, and which bees are we talking about? Is it their first food? Do bees actually use the pollen and nectar from dandelions?
Just because social media says its true, does not mean it is. Lets uncover the truth behind this new craze to save the dandelions.
Bees First Food
I grow a lot of plants in my garden and I seem to remember many things flowering before dandelions (Taraxacum officinale). I spoke to one of the researchers at the Honey Bee Research Center, University of Guelph and asked him about the bees first food.
Around here, zone 5, Ontario, “their first important food source is tree pollen. Long before flowers become important, honey bees are in the top of trees collecting pollen. Maples, elms, poplars and willows are important as a first food” and they flower before dandelions.
“They gather dandelion pollen when other pollen is not available.”
Some trees are wind pollinated and produce a lot of pollen. They also have a very concentrated source which means bees don’t have to fly long distances between flowers to get it.
What about herbaceous plants?
Lots of things bloom before the dandelion. This year I kept a record of early flowers in my garden and got help from people on our Garden Fundamentals Facebook Group, who also contributed to the list. All of these flowered before dandelions.
- Snow drops
- Japanese Butter Bur
- Winter aconites
- Crocus
- Vinca minor
- Hellbore
- Lamium
- Primula
- Hyacinth
- Violet
- Iris reticulata
- Scilla
- Pushkinia
- Draba
- Erica (Heath)
- Spring beauty
- Spicebush
- Pulmonaria
- Coltsfoot
- Epimedium
- Muscari
- Pulsitila
- Muscari
- Daffodil
- Anemone blanda
- Corydalis solida
- Hepatica
- Virginia bluebells
It is clear that dandelions are not a bees first food.
Fruit Trees vs Dandelions
Last spring I found a field of dandelions, and right beside it was a row of flowering ornamental pears. Thousands of flowers on both plants, all in prime condition, on a nice warm, sunny day.
Where were the bees and other insects?
Almost none were on the dandelions. The pears were covered with insects and you could hear the hum they made several feet away. I found a wide range of insects; different kinds of bees and flies, including honey bees. You would think that in such a crowded environment some would go to the dandelions where there was no competition, but that was not happening.
But the story is more complex. Dandelion flowers produce peak pollen between 10:00 and 11:00 A.M. (between 8 and 14C) and close in the afternoon. Apples (don’t have numbers for pears) produce peak pollen between 12:00 and 4:00 P.M.. So it is possible that you might find bees on the dandelions in the morning and on the fruit trees in the afternoon. I can’t remember what time I was there?
There is also evidence that once a bee is conditioned to dandelions, or any other flower, they will stick to sourcing pollen from it for a few days. Even if fruit tree pollen is available, they ignore it, once conditioned on dandelion pollen. An abundance of dandelions may in fact keep bees from the fruit tree pollen, which is a more nutritious source of pollen.
Do Bees Use Dandelions?
Bees do use dandelions for both nectar and pollen. They especially like a lawn that is full of them since this makes it easy for them to collect a load of pollen. According to the Honey Bee Research Station, it is not a preferred food, but it does help fill the gap when other sources are not available and in spring dandelions exist in abundance.
Quality of Dandelion Pollen
“Honey bee foragers collect nectar, pollen, and water from flowering plants. Pollen is the honey bees only significant source of protein, lipids, minerals, and vitamins, all of which are necessary for brood‐rearing, normal development, and worker longevity.” Nectar is a source of carbohydrate that provides energy for bees.
Protein contains amino acids, and some of these amino acids are essential. That means the organism can not make them; they have to get them in food. Dandelion pollen is low in valine, isoleucine, leucine and arginine, essential amino acids for honey bees.
Dandelion is consider a poor quality source of protein for bees.
Variety is the Spice of Life
Collecting highly nutritious pollen is important for bees but variety seems to provide them with a better ability to fight off disease. What they really need is a variety of pollen.
The type of pollen collected is influenced by the ease with which it can be collected and not by its nutritional quality. Honey bees can’t seem to tell which pollen is more nutritious. There is some evidence that bumblebees select better quality pollen.
If we make it easy for honey bees to collect poor quality pollen by creating a lawn full of dandelions – that is what they will collect. A lawn of dandelions keeps bees away from more nutritious pollen.
Even more important is to have access to pollen and nectar at all times when they are active. Native bees tend to emerge when temperatures rise above 55ºF. Bumblebees are often the first bees to emerge in spring and the last bees to be foraging in fall. Other native bees out in early spring include, Andrena spp. (mining bees), Hoplitis spp. (mason bees),Osmia spp. (mason bees), Lasioglossum spp. (sweat bees), Anthophora spp. (digger bees), Nomadaspp. (cuckoo bees), and Ceratina spp. (small carpenter bees).
Honey Bees vs Native Bees
Most of the research is based on honeybees, some on the bumblebee, and we know very little about most other native bees. They probably have similar nutritional needs, but we don’t know.
Click this link for more information about the topic of honey bees vs native bees.
Do Bees Need the Dandelions?
Dandelions are not the first source of pollen for bees.
The pollen from dandelions is of poor quality, but better than nothing. They do provide a good source of nectar.
Keeping dandelions may keep bees from using fruit tree pollen which is a better quality of pollen. In this way dandelions may actually be harming bees.
A lawn full of dandelions is better for bees than a weed free lawn, but not nearly as good as a garden with a variety of plants and no dandelions.
If you must have a lawn, consider planting fruit trees, even ornamental ones, and skip the dandelions.
The way this is presented assumes that there are other nectar sources. Living in the suburbs filled with toxic lawns, articles like this only encourage more herbicide use.
Allowing dandelions to grow also encourages more pesticide use, since most people want a lawn without them.
But that is not the point of the article. It is better to grow other nectar sources.
Spreading a globally invasive species is NOT the solution to reducing herbicide use…I am trying grow a native grassland (same habitat) in North America and the massive increase in dandelions by people who get poor quality information on Facebook and then my property is INUNDATED has me really wanting to reach for the round-up. Dandelions do not support lepidopterans as well as native plant diversity. Any ecologist can tell you a huge monoculture may seem like a great idea to people, but does not serve the larger ecology. Since dandelions (and clover) do not “play well with others” (allelopathic) and does not stay where planted, it is likely that more rather than fewer chemicals will be used. People spreading dandelions where they are not native are causing more harm than good in spite of their well-meaning intentions. I love Dr. Palvis’ link to Doug Tallamy’s work…exploring this might result in a deeper understanding of what is needed to support ALL insects birds, etc…not just the honey bee, which is itself an exotic agricultural animal implicated in disease transmission to our native bumblebees.
Thanks for this. My yard is dandelion free, as much as possible, I dig them out if found. But while other yards may have them blooming my yard has bees at the early flowers – weeping pussy willow, hyacinths (sweet smelling so I assume full of nectar). And one small (12′ at the moment) crab apple tree recently was abuzz with bees – honey bees, bumble bees, sweat bees and a Mason bee thrown in. That one tree has more flowers than a yard full of dandelions. And later the cardinals eat the tiny crabapples while wild turkeys clean up what falls to the ground. Not to mention my other trees. So while I wasn’t going to grow them in my grass at least now I don’t have to feel guilty that I’m starving the poor bees.
Why bees are robbing from the weaker colonies and some time destroy entirely? Can it be avoid? I am talking about cerena indica bee.
Another factor that can’t be ignored is where the plant will grow. Anemone blanda, taking one from your list at random, will grow generally only where someone has chosen to plant it, creating a cost bottleneck (labor, time). It’s also much fussier about conditions (trampling, moisture, zone, soil, competition, etc.). If not, the plant would be considered invasive. Although so have not investigated it, I bet it produces quite a lot less nectar than the dandelion — based on the low levels in Anemone in general (and the related Ranumculus genus). I also bet it is more specialized in terms of what kinds of pollinators use it. Regardless, it is no match for the dandelion when it comes to efficiency (planting itself, growing well without human help, not costing money, etc.) — in terms of large-scale relevance. I would rather have it growing with dandelions also versus having just one or the other. Surely that would be better for bees in general, even if the honeybee has more specific preferences.
First, many of us are talking about North America, so applying what works in the UK to here does not always work. Second, when speaking of a narrow approach, it is highly “narrow” to be speaking of honeybees alone. In North America there are FOUR THOUSAND native bees and their needs to cover, and native plants is how they have survived for millenia…planting dandelions in a lawn does not begin to cover their need for diversified habitats, and a succession of blooms. Finally, Robert speaks of truth…science is the best way to get to that, although the path may be long, twisted, and rocky. I see you making a vast number of “bets” in your statement, which suggests to me you are more interested in justifying your own beliefs than finding out what will be the best thing you can do. Each of your assertions should include some reference to the science, and from reputable authorities, as you will note, Robert takes pains to do, which is why I come to read what he writes…because finding the references and writing about what they are saying is infinitely harder than simply making claims. You also neglect any consideration for your fellow human beings, who may not appreciate your fostering a highly invasive plant.
A UK study of meadow pollen and nectar production found that “weeds”, including dandelions, are very valuable source of early season nectar. In fact, the widely-hated ragwort topped the list in nectar level and trounced the perennials in the study. Overemphasis on pollen misses the value of dandelions. Many flowers focus even more strongly on producing just one or the other. Poppies, for example, are loaded with pollen but produce no nectar. To expect flowers to be equally (or close to it) worthwhile is to miss the guidance of actual nature. So many flowers specialize, not just on pollen vs. nectar but many variables within those. A species of dry land iris offers no pollen and no nectar but it enables pollinators to stay inside for protection.
And pears are so poor-quality in terms of pollinator reward that people resort to planting apple trees next to them just to attract enough bees to get the pears pollinated. Ornamental pears are an unfortunate thing for pollinators. They bloom at the same time, offer low rewards, and are used instead of much more valuable alternatives. There are so many trees that would do more than Bradford Pear.
Clover flowers offer little nectar and pollen but the pollen is high-quality. So, if lawns have both abundant clover and abundant dandelions it may be that the poor quality of the dandelion pollen becomes less relevant. As someone said, pollinators are in vastly better shape when there are more floral resources available, not low-cut grass “green deserts”. Grasslands have been shown to produce far less pollinator resources in that UK study, versus form-rich meadows. Grasslands have wildlife value but not so much for many pollinators.
Aster family plants have been found to have lower-quality pollen and yet one sees all sorts of plants in the Asteraceae family being heavily promoted as “bee plants” and such. Things aren’t so simple. Research finds that sunflower pollen leads to lower bee nutrition (and Asteraceae in general). So, let’s all plant something else, right? Not so fast. Research also finds that sunflower pollen reduces parasite load in bees.
I suggest looking at all of the variables. And, if you’re going to go after the value of a plant to honeybees it’s important to look at its value to other species. People are enticed to jump to bad conclusions when information is presented too narrowly, especially with a layer of hype. Butterflies often rely on dandelions when little else is available. They don’t care about pollen and many small butterflies can handle dilute nectar. The Black-Eyed Susan is another example of how not looking at all variables can lead us to bad ideas. It has very low nectar and pollen production (so plant something else instead, right?) and yet it has been found to be the preferred source of food in the wild for several species of butterfly — chosen over more resource-laden plants nearby in some cases. And yet, it’s also widespread and allelopathic so sometimes it’s not the best choice (yet is used in virtually all government forb mixes because the seed is cheap and the plant is an aggressive pioneer species that looks like it’s doing a lot of work making nectar and pollen).
Also, when you make a list of what else is blooming at the time remember that many pollinators have specialized needs so certain flowers are useful to them and others aren’t. Generalists like the dandelion also serve as a better-than-nothing last resort, probably the same reason you’ve seen heavy action on pears.
I work at an environmental education facility and I promote dandelions because I don’t want people poisoning wildlife, their family and pets (cats inside!), and the ground water with chemicals.
I think it would be better to just be honest with people.
I’m actually more curious about whether dandelions attract earthworms. When weeding, I find a lot of the time there’s a worm twined around the dandelion’s root.
Also- if people want to make their lawn a source of food for pollinators, let there be clover!
I have noticed this too…and that milky slugs (introduced from Europe same as the dandelion) hide under their leaves but don’t eat them and come out to wreak havoc on my attempts to grow many native species. They decimate the native orchids, which have no co-evolved relationship to, or defenses from them.
One point that has not been made in this conversation, is that there are a host of different species that look similar to dandelions, some more destructively invasive. Hawkweed, Catear, Hawkbit, and a host of plants that are introduced that can have (as yet relatively unstudied) collective impacts. Many are allelopathic. Robert, have you done a piece on that yet? The emerging science is fascinating. One in five plants in Canada is introduced, and most people don’t look at plants carefully enough to actually know the correct identity of what they have. I have yet to find any place that is not impacted by the recent arrival (in the last few hundred years) of human introduced species. The “Fall Dandelion” could pass easily…Scorzenoides autumnalis…was not in my area 10 years ago and is moving out my native AND introduced grasses fast…makes the dandelion look like a pansy in that it is just as hard to remove and makes colonies. Know Thy Plant (and its story, and who in the ecology it is serving…or not).
https://www.gardenmyths.com/walnuts-juglone-allelopathy/
I’ve been recording pollinators for about 10 years now, and I have found many bumblebees, solitary bees and hoverflies on them (SW Ireland). It may not be top quality nectar and pollen, but quite often, especially in rural areas, it is the only or one of very few sources early spring. Bumblebee queens, having hibernated and eaten nothing at all for various months, are highly vulnerable to dying from starvation in spring. What’s more, the leaves/roots are food to many herbivorous insects and the seeds are important to many birds – so it’s not just nectar / pollen that benefits wildlife, it’s the whole plant in all seasons. I’m not saying never ever remove a dandelion, but outside your prime flower beds, please do leave them be(e)!
I am just trying to decide if I should mow my field of dandelions or leave it to help the bees. The fruit trees are not in bloom yet but if I leave the dandelions til they go to seed our vegetable garden will be full of dandelions.
You talk about honey bees, but they are only one species of pollinators. A domesticated one, in fact, with very different gathering behavior from wild bees. While a hive of honey bees decide on one main source of nectar/pollen at a time (thousands of workers focusing on that one source), wild bees work individually, flying from flower to flower as they browse through the landscape. So while this article is correct when it comes to honey bees (managed and feral), it doesn’t apply to wild bees, which are the ones who are truly in danger. I’m a beekeeper myself, in Europe, and I have to say that honey bees are not dying out. They are under a lot of stress currently, but that is our fault (spread of disease across borders, stresses from migratory beekeeping and intensive management, poor nutrition). But being domesticated, we can always breed more to replace those who die out. At least that is the quick fix we go for, instead of looking at what we may be doing wrong in the first place.
The wild bees and other pollinators, however, are on their own. And they are much more threatened than our domesticated bees. To put it simply, they suffer from the impact we humans have on our environment. Lack of habitat is maybe the most important, including monocultures. But wherever our modern society spreads, insects suffer.
With that in mind, I don’t think there’s anything wrong with asking people not to cut their lawn when the dandelions are in bloom. But you’re right that it’s not the first nor the most important source of pollen and nectar. The one type of flower that I would recommend people to leave standing in their lawn are clovers. Bumble bees love those!
A lawn without flowers is a desert to pollinators. The best you can do for the bees is to replace your lawn with bee friendly flowers. Life begets life. The more life you have in your garden, the more you will encourage life. Modern society brings death, but each one of us can counteract that if we want to. To quote Trainspotting: choose life!
The reason I talked about honeybees is 1) it is the only bee where I was able to find the information and 2) it is better studied.
If you have pollen collecting references or references about the quality of dandelion pollen for native bees, I’d certainly include it.
I don’t have a problem with leaving dandelions – I have a problem with people making exaggerated statements about how important they are for bees.