Those with beautiful flowers are the most popular and widely appreciated plants in gardens. It is generally believed that plants with exquisite flowers will be attractive to bees and other insects who visit flowers. A more empirical view can be gained from the Laboratory of Apiculture and Social Insects of the University of Sussex.
In a project that was carried out in 2011/2012, 32 types of summer flowering plants were grown in beds. The insects visiting these plants were counted – 87% being bees. All of the plants chosen were summer-flowering types that are often found in gardens.
All were appealing to the human eye. They were all attractive to the human eye, but they were different for insects. Marjoram and Agastache were the most appealing to them. It is a perennial herbaceous plant with small spikes of flowers and simple aromatic leaves. The pelargonium was the least liked, with 100 times more insects.
Making a Difference
This is a very simple lesson. Gardeners can make a difference by choosing varieties that provide pollen and nectar. Our research shows that it is not necessary to spend a lot of money in order to help bees or flower-visiting insects. In a survey of over 200 varieties of asters (also known as Michaelmas daisies) at the British National Collection, Picton Gardens in Herefordshire, the varieties that attracted the most insects were the same as the others. They were also easy to get, easy to grow, and appealing to the eye. The prices are the same, but it depends on the size of your plant at the time you purchase it.
How beneficial are flowers in gardens and parks to insects? In Lewes, East Sussex, there is a park called Southover Grange Garden that is well-managed to produce beautiful floral displays during spring and summer. In August 2012, we counted insects of 79 different varieties.
The findings were unexpected. Only three varieties of flowers were particularly attractive to insects that visited the flowers. In 15 counts, we found no insects on 24 of the varieties. On another 37, there were only a few. There is clearly room for improvement. Many garden flowers have been bred to produce many bright petals rather than food for bees.
Turning a new page
There are more than 2,000 retail nurseries and garden centers in the UK. These are the most popular places to buy plants and gardening equipment. (And for a cup of tea and a piece of cake). They are important in determining what British gardeners will grow and which insects can visit.
In most garden centers, the plants are in full bloom. Each variety is displayed in its patch. It is easy to keep track of the insects. In 2015, we counted insects on 59-74 varieties of plants in full bloom that were sold in five garden centers in Sussex and one nursery. In each garden center, we made 12 counts in one day. We brought our marjoram to create two comparison patches.
The pattern we found was similar to the two other studies. The majority of the varieties sold had few bees or other insects, and only a few had a lot. As expected, our marjoram performed well. However, 4.5% of plants sold were even more attractive, with 26% more insects on average. Cosmos bispinnatus ‘Sonata Carmine’ had deep magenta-colored flowers, while caryopterisxclandonesis ‘Heavenly Blue’ was a compact shrub that had clusters of dark blue flowers.
About 15% of the plants were sold as being bee-friendly. Just over half are on the Royal Horticultural Society “Perfect for Pollinators list.” What were the results? The average is good. Recommended plants attract three times more flower visitors than the rest. Many of the plants in this group did not perform well or were unattractive to insects. Some varieties that were not recommended, such as Iberis “Masterpiece or Alstromeria “Inticancha Deep Purple” performed well. Labeling appears inconsistent and overly optimistic. Maybe “better pollinators” is more accurate.
Our research has shown that by choosing flowers more carefully, the public can make their gardens more attractive to bees. Garden centers can play a part in this by increasing stock and educating their customers to choose more attractive varieties.
The family Lamiaceae is a great family for pollinators. This includes marjoram, thyme, and Russian sage. Daisies include selenium, some dahlias, and other flowers. The different varieties can bloom at various times and provide food to many flower visitors throughout the summer.
Look around your local garden center during a sunny day in the summer if you’re interested in helping bees or other insects. The best plants are those that have ten insects per square meter, or even 5. Don’t purchase a plant you dislike. There are many bee-friendly plants, so you can have a win-win situation: choose plants that both you and the bees will love.