You can be sure that the trending words this year will be biodiversity and plants for pollinators! They are on everyone’s lips, we read them in every text that talks about environment and yes, I admit it, I’m kind of a bee hugger myself!
This isn’t surprising, since there are many factors that hinder the good health of pollinating insect populations. Loss of habitats, urban pressure, pollution, pesticides, parasites… It’s quite normal to want to do our part in order to counteract all these harmful effects. One of the solutions proposed to contribute to the good health of populations of pollinating insects is to grow plants that attract them. Plants rich in nectar are part of the lot.
Pollen, Honey or Nectar?
Let’s play with words a bit. We often hear about melliferous plants, pollinating insects and nectariferous plants. Even if these revolve around the same subject, there are small nuances to be made. First, pollen is the male element of the flower. It could be compared to spermatozoa in animals. These are small microscopic grains, generated by the stamens. In some plants, the pollen grains depend on a carrier, which can take it from one flower to another. In some cases, these carriers are insects: pollinating insects. The pollinating insect is therefore the one that transports the pollen and ensures the reproduction of a flower.
For honey bees, pollen is very important because it is used to feed the larvae. Bees also store pollen and make reserves, in order to survive in times of scarcity. A hive without pollen is doomed to certain death. And of course, along the way, the bees drop here and there a few grains of pollen which will fertilize the flowers.
As for the nectar, it’s a sweet liquid, usually excreted by flowers. Nectar is the main constituent of honey! The secretion of nectar by the flowers is one of a the stratagems used to attract pollinating insects. While gorging on nectar, the over-excited insect catches the pollen as it passes by. Thus sprinkled, the insect goes to conquer another flower and deposits this traveling pollen there. Mission accomplished, the flower is fertilized!
Then there are bee plants, or melliferous plants: those with which honey is made. As you will see, melliferous plants are necessarily nectariferous plants, because it is the nectar that becomes honey. And on the other hand, it is possible that a nectariferous plant does not enter into the composition of honey. Even if the bee is the big star of pollinating insects, it’s far from being the only one to contribute to the pollination of plants. It’s estimated that there are nearly 100,000 species of pollinating insects in the world! And probably just as many nectariferous plants!
And the Winners are…
Phew! How to choose the best nectariferous plants in this ocean of possibilities? It’s quite a challenge. To achieve this, I conducted a review, which I would describe as artisanal, of various scientific articles. I also focused on North American plants. And I must admit that some results surprised me. We always have in mind a certain list of plants that are the great classics when we talk about plants that attract pollinators. Also, it should be noted that the majority of nectariferous plants are also the favorites of pollinating insects. So there is a great correlation between pollen and nectar. Here they are in any order. They aren’t necessarily the most productive, only the ones whose names are mentioned the most often (according to my research). Calculating the amount of nectar secreted by a flower depends on so many factors that I am at a loss.
Whether white clover (Trifolium repens), red clover (T. pratense) or hybrid clover (T. hybridum) grown in the field, clover is a very nectariferous plant. Moreover, the Fabaceae botanical family, of which clover is a member, is recognized as one of the five major plant families that are rich in nectar. Sweet clover (Melilotus spp.), trefoil (Lotus corniculatus), tufted vetch (Vicia cracca), and black locust (Robinia pseudoacacia) are also plants of this large family which are often cited.
This was the first big surprise. Plants that attract insects are often associated with beautiful large flowers with brightly colored petals, either purple, blue or yellow. It can’t be said that the flowering of maples (Acer spp.) is the most spectacular, but it is indeed nectariferous. And yes, the sugar maple (Acer saccharum) does appear in the scholarly literature. I don’t think it’s a coincidence!
Second twist! Red osier dogwood (Cornus sericea, formerly C. stolonifera) is not only one of the most cited nectariferous plants, but it is also one of the best sources of pollen for some hives! It is indeed the beautiful shrub with bright red stems that spreads naturally in ditches, open fields and slopes. Its branches are so decorative that it’s also grown in gardens. It’s one of the great classics for the revegetation of banks. Again, it doesn’t have particularly spectacular flowering, but it knows how to get love from insects.
This makes me so happy! I like to think that I continuously namedrop the dandelion (Taraxacum spp.) in all my articles, since I love this one so much! In addition to its thousands of other qualities, the dandelion is also a plant rich in nectar. In addition, early spring being a period when nectariferous plants are scarce, the importance of the dandelion must be underlined! Indeed, if it’s warm and sunny early in the spring, the insects are actively looking for food, but flowers are not always to be found.
These also surprised me! Like maples, I didn’t expect silky willow catkins to be particularly rich in nectar. It is however the case. Like dandelions, willows (Salix spp.) have a very early flowering period are among the first plants visited by pollinators in spring. They are therefore very important to meet the needs at the beginning of the season, when all the other flowers are waiting.
Raspberries (Rubus idaeus) are also part of a large botanical family of plants very rich in nectar: Rosaceae. While raspberry is the plant that comes up most often in the lists, the importance of plum, cherry, hawthorn, serviceberry and apple trees is also mentioned. I was surprised not to see the apple tree stand out more often.
Borage (Borago officinalis) is a beautiful annual that is usually grown for its edible flowers and leaves. And personally, I always suspected that borage was a plant rich in nectar, because the flowers are particularly sweet in taste. Then, it has the classic profile of the plant that attracts insects: petals of a beautiful bluish mauve, flower wide open like a beautiful landing strip, summer flowering…
The plants of the mustard group (Brassica spp.) are among the plants often cited, because several species of this genus are cultivated in field crops in several regions. Canola (Brassica napus), in particular, is part of this group. But most wild mustards, which grow in ditches and fields, are also known for their nectariferous qualities. This is the case of the classic field mustard (Rhamphospermum arvense, formerly Brassica kaber).
To hear the incessant hum of a clump of goldenrods (Solidago spp.), it’s not surprising that these plants are rich in nectar. It’s one of the beautiful native plants of North America and there are many species, each more interesting than the other. Goldenrods also mark the end of summer, as do fall asters, like the New England aster (Symphyotrichum novae-angliae), which also carry nectar glands. Late season plants are just as essential as early spring plants, as fall is also a time when food is becoming increasingly scarce for nectar lovers.
Yes, Nectar, But Not Too Much!
For the beekeeper, nectar-rich plants are great! The more nectar, the more honey! On the other hand, for plants, the production of nectar has a single purpose: to attract insects in order to ensure the reproduction of the plant.
If the plant is too generous in its production of nectar, the insect will quickly be full and it will rather to take a nap more than visit another flower. It is therefore a fine strategy and a skilful game of balance that dictates the quantity of nectar that a flower will produce. Just enough to attract insects while enticing them to visit as many flowers as possible before building up a full meal!
While doing my research, I also discovered that the spirea (Spiraea spp.), meadowsweets (Filipendula spp.) and poppies (Papaver spp.) do not secrete nectar, even though they are insect-visited plants. Then, in contrast, alfalfa (Medicago sativa) is visited mainly for its nectar. How fascinating it all is!
So, in 2023, to remain trendy and contribute to the development of biodiversity, it’s in our best interest to encourage, protect, plant, sow and fall in love with all these beautiful plants that are part of the wonderful ecosystem of pollinating insects and divine lovers of nectars.
A bit of history
The importance of insects in the pollination of plants is a relatively recent discovery in the history of “modern man”. Indeed, the first studies on the subject date back to the end of the 1700s, when Joseph Gottlieb Kölreuter became interested in pollination by insects, closely followed by Sprengel who studied the fertilization of flowers. For a long time, the works of both were shunned and it was our famous Darwin who was able to win the honours, even if others had preceded him in his discoveries!
Great article! I love pollinators. As far as bees go, my focus is on native bees. They are out on colder and wet days, unlike honeybees. So I try to ensure there are lots of plants for them throughout the seasons. I think this takes care of a large variety of pollinators, which I love to watch.
However and importantly, dandelions lack 4 essential amino acids for native bee health as reported here. https://www.ruralsprout.com/dandelions-for-bees/
Always great to plant nectar rich plants into the garden. Here are a couple of excellent annuals that I always have in mine: Celosia serrulata (native to Alberta) and Phacelia tanacetifolia- both nicknamed beeplants as they are loaded with nectar- are always alive with pollinators.
It’s wonderful that planting for pollinators is now trendy! I’m now 70 years old but I was raised in my grandmother’s garden. She taught me from the git-go to tend the bees. In her old world accent, she told me “You love the bees and they won’t hurt you.”
She was right. Although I don’t keep bees for honey, we work side by side in the gardens and I’ve never been stung.
List of Northern American nectar sources for honey bees
Plant type Nonscientific name Scientific name Begin Bloom Month End Bloom Month Monofloral honey Availability Source for honey bees / pounds of honey per acre
T Maple Acer 1 5 no feral major but temperature usually too cold
T Red maple Acer rubrum 1 5 no feral major but temperature usually too cold for bees to fly
T Ohio buckeye Aesculus glabra 4 5 no feral minor
S Shadbush Amelanchier arborea 4 5 no feral minor, or major depending on location and weather.
S, T Devil’s walkingstick Aralia spinosa 7 8 no feral minor
My plan for our new lawn in the spring is a mix of fescue and clover.
You can not eat grass, please reconsider your efforts and returns, Happy Holidays John H.