For many of us, our pristine lawns are a thing of joy and pride, so when weeds like clover begin to emerge, it can often set our blood pressure on the rise. However, before you grab the herbicide and blanket your lawn to remove the herbaceous pest, have you ever stopped to see if any bees were visiting these plants? Bees are usually not picky when collecting nectar and pollen, but so bees like clover?
Bees like many different types of clover. Many bees, including honeybees, are generalists who visit a variety of floral sources for nectar and pollen. Most bees visit clover of the Trifolium species. They particularly target crimson and white clover.
Although many of us consider clover a weed, it plays a critical function in the environment by providing nectar and pollen for pollinators like bees. But which bees like clover? Do they like a particular type of clover? What type of honey comes from clover, and what are some pros and cons of bees foraging from clover plants?
Clover (Trifolium spp.) are herbaceous plants belonging to the pea family (Fabaceae). There are annual and perennial plants that account for roughly 300 species.
Indigenous clover is widely distributed globally in many subtropical and temperate regions, except for Australia and Southeast Asia.
Clover is an angiosperm (a flowering plant), often grown commercially as feed, and it attracts bees so well that honey from clover is a secondary product of clover agriculture. Cultivated clover is exceedingly successful in temperate regions.
Clover’s wide distribution, ability to survive in arid and other adverse conditions, and clusters of flowers contribute to clover’s significance as a forage source for many bee species.
Aside from its distribution, many clover plants also have moderate pollen, and nectar counts, making them efficient collection points and desirable to bees.
Although many bees are generalists and take nectar and pollen from any clover plants they find, there are several clover species that bees come into contact with more frequently, including:
The white clover derives its name from the minute white (and pink-tinged) flowers that develop in clusters during early spring. T. repens is the most commonly occurring clover species in lawns due to its hardy nature, ability to grow in adverse conditions, and ground cover growth.
White clover grows wherever it can establish itself, including ditches, fields, and roadsides. White clover has average pollen and nectar count.
Red clover also derives its name from its flowers, which are dark pink. Although not a primary lawn species (the higher growth form makes it less suitable than white clover), the T. pratense is an agriculturally important species with a wide distribution.
Crimson clover is another agriculturally important clover species named for the color of its flowers. T. incarnatumimproves the soil quality, stabilizes soil in arid areas, and increases the pollination of crop species due to the high amount of bee traffic these flowers attract.
Various bee species visit crimson clover.
Another commercially important clover species is Alsike. Although Alfalfa is slowly replacing it, T. hybridum is used as a livestock feed. Canada is one of the significant producers of Alsike clover, of which the US imported roughly 3,715,000 pounds in 1969.
This clover is well adapted to surviving wet and harsh winter conditions.
Bees collect pollen and nectar from clover flowers.
During his experiments in 1965, Weaver noted that honeybees take roughly 26 minutes to collect an average pollen load, equating to roughly 18 to 19 clover flowers every minute.
Conclusions drawn between Weaver and Oertel’s work in 1954 suggest that bees must visit between 450 and 520 clover flowers to collect a full pollen load.
After returning to their hives, bees convert the nectar and pollen into honey, royal jelly, bee bread, and numerous other products.
Many bees are generalist species, meaning they do not discriminate against collecting pollen from many plants.
Honeybees are generalists because they use a wide range of floral species to produce honey and other important products.
Honeybees are frequent visitors to white and crimson clover due to the plants’ short tubes, allowing easier access to the nectar glands.
Honeybees are the primary pollinator species of white clover. These bees are commercially important for the honey industry and pollinating crops.
Honeybees are also the principal pollinator species for Alsike clover (Trifolium hybridum).
Bumblebees are larger, have longer tongues than honeybees, and are more apt to obtain nectar and pollen from the red clover, which has a significantly longer flower tube.
Bumblebees also frequent white and crimson clover due to their generalist nature.
Although not limited to Honeybees and Bumblebees, these bee varieties are the more significant pollinator species of the various commercially important clovers.
Other bees that collect nectar and pollen from various clover plants include:
- Carpenter bees (Xylocopa spp.)
- Mining bees (Andrena spp.)
- Leafcutter bees (roughly 63 species and 5 subspecies)
- Other Solitary bees (over 200 species)
- Stingless honeybees (tribe Meliponini)
In nature, a special relationship often develops between a particular animal and plant species. These animals often become specialists, targeting a select group of plants. Specialists often struggle when competing with generalist species.
Clover produces an average to a goodly amount of nectar and pollen. It has an appealing smell, and many varieties have vividly colored flowers.
These (and other) factors attract bees to the clover plants. Although a species of bee might actively avoid clovers, it is highly unlikely.
Of greater consequence is that not all bees can use all types of clover.
Red clover, for example, has longer floral tubes, which restricts the number of species that can use this type of clover.
There are other similar examples. So while some bees might not actively avoid clover, they may struggle to collect sufficient nectar and pollen from certain clover species, depending on their physiology (size, tongue length, etc.).
Bees often collect nectar and pollen from clover flowers because of their abundance. While there are many benefits from bees using clovers as a food source, there are also some distinct drawbacks.
The advantages of bees foraging from clover include:
Clover, like most plants, contains chemical deterrents which prevent animals from eating them.
White clover contains two cyanogenic glucosides, linamarin and lotaustralin, which botanists believe releases hydrogen cyanide, a toxic chemical.
Researchers recently discovered that when honeybees collect pollen and nectar from white clover, they can ingest these compounds with no adverse effects.
On the contrary, bees retain a reduced concentration of cyanogenic glucosides. Researchers believe that in these lower concentrations, the secondary metabolites assist the bees (and other pollinators) in fighting against diseases and predators.
Further research is required to fully appreciate the factors at work.
The most significant boon to bees using clover is that these plants are incredibly hardy. They grow in arid areas, disturbed areas, on roadsides, and wherever else they can establish themselves.
This hardiness means that bees almost always have access to sufficient food sources, even in urban areas where other flowering plants might be limited.
Many farmers realized that if they planted clover between their crop beds, the number of bees coming to the fields would increase dramatically. This increase in bees results in better pollination and healthier crop production.
Bees (particularly honeybees) are an important pollinator species and contribute to clover’s ability to re-seed. More clover means more bees, which leads to more clover seeds developing into clover plants in a perpetuating fashion.
Some disadvantages associated with bees foraging from clover include:
In many places, clover is often considered a weed. Its hardy nature, widespread distribution, and ability to naturalize allow it to invade an area and take over, replacing indigenous plants.
While this may not be too critical in a lawn environment, national parks and other natural areas don’t want alien species running rampant.
When bees pollinate clover, they are less effective in pollinating other species (within reason and if there is a severe clover “infestation”). Additionally, bees perpetuate clover propagation through pollination.
Clover is widespread, and honeybees often come into contact with it, which is problematic from a commercial honey production standpoint.
Many beekeepers try to create “pure” honey (monofloral honey). If a clover field is close to the apiary, there is a significant chance that the honey will become multiflora (more than one species of plant’s nectar).
Multifloral honey is usually not as expensive as monofloral honey, and those paying for top-quality might not appreciate the clover honey mixture.
Although clover is a widespread plant, some factors prevent bees from accessing clover strands, including:
A study in 1957 by Green concluded that the distance from the hive to the food source (flowers) was indirectly proportional to the number of bees visiting. I.e., The further the distance away from the hive, the fewer bees would visit the flowers.
For example, there were 6.3 bees per 1 000 flowers at a distance of 105 feet from the hive. The average number of bees per 1 000 flowers dropped to 5.2 at 2 927 feet from the hive.
Although not drastic reductions, the number of bees would continue to drop with sufficient distance.
Unfortunately, we fracture natural environments as we expand, develop, and create infrastructure. When nearby, natural processes (like pollination) are possible; however, pollination (and other processes) decreases as distances between natural areas increase.
Bees have a limited range that they fly to find food, and obstacles like highways, cities and degraded areas hamper bees in their foraging.
Honeybees are successful competitors due to their generalistic nature, and they often ostracize indigenous and specialist species.
As honeybees increase in an area, other species begin to decline. Some species have particular dependencies/relationships with specific plants, and as they are replaced, the process might no longer work effectively.
Certain areas’ climates are unfavorable for bees or clovers to thrive, and planting a clover field might be futile. When conditions are too cold, bees are less efficient and effective pollinators, which could lead to lessened clover yields.
Honeybees are responsible for converting nectar and pollen collected from clovers into the delicious golden liquid we know and love.
Clover honey (the honey derived from clover plants) is a commonly occurring type of honey. Clover plants are widespread and hardy, meaning that a honeybee hive is usually close to a clover field.
Honeybees mix clover nectar with other “wildflowers” to create multi-floral honey.
Clover honey has some particular benefits, including:
- It is a great source of calcium, iron, magnesium, potassium, zinc, and vitamin C.
- A teaspoon of clover honey contains 0oz of fat, fiber, and protein, 0.6oz of carbohydrates, 0.5oz sugar, and 64 calories.
- Clover honey (like most other types) is a good source of antioxidants, including anti-inflammatory antioxidants, but not as many as dark honey varieties (clover honey is light in color).
- Although lacking in vitamins and minerals, clover honey contains flavonoids and phenolic acid.
- Clover honey can help regulate blood pressure, improve mental and heart health, and reduce the chance of disease (including Alzheimer’s disease, diabetes, cancer, heart disease, and Parkinson’s disease) by helping your body process free radicals.
The most significant drawback to clover honey is that it contains sugar (although they are natural and far superior to refined sugar). Consuming clover honey (or any honey) in copious amounts increases your risk of developing diabetes.
Clover is a marvelous plant that provides many benefits other than facilitating bees in their foraging and honey production.
Further uses of clover include:
- Clover is a source of livestock feed.
- Clover is a type of cover crop.
- Clover is useful as green manure.
Clover belongs to the pea family, making it a legume. A unique characteristic of these plants is that their roots contain nitrogen-fixing bacteria, and their presence improves the soil by increasing the amount of nitrogen (a critical component to plant growth) available to grass and other plants.
Without a doubt, bees like and forage from clover flowers. They collect nectar and pollen from these plants and are critical pollinator species for many clover varieties. Some commercially important clovers include white, red, crimson, and Alsike clover. The most important pollinators of clover are Honeybees and Bumblebees. Although many consider clover a weed, it facilitates bees and other plants by producing nectar and pollen and enhancing the soil.