Dragonflies are great aerial acrobats and fun to watch. They are a nice addition to any garden and they eat large numbers of mosquitoes. The best way to attract them to your garden is to create a dragonfly pond which will give them a place to breed and raise their young.
In this post I’ll provide the information you need to build such a wildlife pond.
Dragonflies and Damselflies – What is the Difference?
Dragonflies and damselflies are closely related insects, but it is fairly easy to tell them apart.
Dragonflies have different shaped fore and hind wings, and they keep them open, like an aeroplane, when they are at rest. They have larger eyes that are close together, almost touching, and their bodies are relatively short and chunky.
Damselflies have wings that are all the same shape and they hold them back against their body when at rest. Their eyes are smaller with a gap between them. Their bodies are very narrow and long.
The natural history of both is very similar and we can treat them as identical for the purposes of this post. I’ll just call them dragonflies.
There are 316 dragonfly species and 131 damselfly species in the US, and about 5,000 species worldwide.
The Life of a Dragonfly
The life of a dragonfly starts as an egg that is laid on or near water and all but one North American species breeds in fresh water.
A nymph hatches from the egg and lives in water anywhere from one month, up to eight years, depending on species.
When the time is right, the nymph crawls out of the water onto a vertical reed, or slanted rock, or it might use artificial wood structures like the footings on a bridge. The adult flying insect then hatches out, dries its wings and flies away. It is quite common to find the empty nymph skins along the water’s edge.
The dragonfly is now very hungry and spends a lot of its time searching for small insects like black flies, no-see-ums and mosquitoes. A large dragonfly can eat more than 100 mosquitoes a day. Their appetite for mosquitoes and their fast-flying ambush acrobatics while on the hunt, have earned them the nickname “mosquito hawk.”
The other important activity is mating. Since the flying stage of the insect does not live very long, it’s important to find a mate and produce fertilized eggs, starting the cycle all over again. Since the eggs are laid in or near water, the dragonfly spends much of its time around ponds. This is also a good place to find insects for lunch.
This whole process is much more interesting than I have described, and there are many different mating and egg laying strategies used by different species, but that is not the focus of this post.
Pond Requirements For Dragonflies
As you can see from the above, a water source is important. You can attract dragonflies to your yard without a water source, provided one exists less than a mile away, but the surest way to attract them is to have your own pond.
The requirements are as follows.
- Provide a variety of depths from very shallow to a couple feet or more.
- Provide a surface area of at least 40 sq ft (4 sq m).
- Select an area with few overhanging trees – dragonflies like sunny areas.
- Use a variety of pond plants, but include ones with vertical stems or leaves.
Building a Natural Pond
I am not going to describe the whole process in this blog. You can check out my book Building Natural Ponds for full construction details.
You can also join our Facebook Group: Building Natural Ponds.
For some videos about building natural ponds, check out this YouTube playlist.
Natural ponds without filters and pumps work better for dragonflies because they encourage a lot of pond life. This pond life is the food that dragonfly nymphs eat. If you add pumps and filters to keep the pond very clean and sterile, there will be less food for nymphs. That does not mean you need to have a stinky pond full of decaying vegetation and algae growth. The water needs to be clean like the local lake where you would swim, but not as clean as some koi pond owners want.
Fish will eat dragonfly nymphs, so it is best not to use fish, or if you do, use only very small ones.
Suggestions for Building the Pond
Variety in vegetation is important for attracting different species. Each species has their own preferred method of egg laying, and emerging into a flying insect. By providing variety, you will have the best chance of meeting the needs of several species.
Plants growing around the outside of the pond will not only make it more natural looking, but they also provide protection and shelter for the adults. Diversity is important.
Include some larger light-colored rocks that stick out of the water. These heat up in the sun and make a perfect perch for dragonflies to warm themselves.
What About Mosquitoes?
Mosquitoes will try to breed in natural ponds and one way to keep them in control is to add some fish. If you don’t add fish in a dragonfly pond, what about the mosquitoes?
Dragonfly nymphs should take care of the problem since mosquito larvae are one of their favorite foods. If that is not enough control you can use mosquito dunks that contain Bt israeliensis. These are floating tablets that release a bacteria that will kill the mosquito and black fly larvae, but will not harm other inhabitants like dragonfly nymphs or feeding birds. They are considered environmentally safe.
Plants That Attract Dragonflies
I am seeing more and more posts that list specific plants that attract dragonflies. Most of these lists are nonsense.
Dragonflies hunt and eat insects. They don’t eat pollen or nectar. They are not attracted to specific types of flowers or scented leaves. Dragonflies are attracted to your garden because of the water and insects, not the specific plants you grow.
Attracting Dragonflies to a New Pond
The great thing about nature is that you don’t have to go out of your way to attract it. It will find you. Build the pond and wait. All manor of insect life will visit the pond and in no time at all you will have mosquito hawks in your garden.