Reasons to avoid mosquitoes are not difficult to find. Their bite does not particularly hurt, at first anyway, but even one bite can become an itchy nightmare, and they seldom bite singly. In addition to being a nuisance, these bites carry numerous diseases, not the least important of which is the dread West Nile virus, frequently the cause of an extremely uncomfortable illness, and too often fatal.
So, mosquitoes bad, no mosquitoes good, right?
Here is the point in a Big Myrtle posting where you expect us to whip out some kind of scientific explanation for why it is important to keep in balance, yada yada yada. If that is what you are waiting for, you are going to have to keep on waiting. On the subjects of fire ants and mosquitoes, we are not objective in the least. We hate the little blighters. And at least some scientists agree with us – a July 2010 article in Nature entitled “Ecology: A world without mosquitoes” posited that there would be minimal impacts if all genera in the family Culicidae were eradicated. We don’t hold quite so extreme a view, but still, it’s nice to imagine.
So… what to do about them?
More on fire ants in a later posting, as they are the more difficult pest with which to deal. Mosquitoes, for a resourceful gardener, are actually one of the easier problems to solve. All it takes is some resource allocation (and no, we don’t mean money, though you may have to outlay some of that), and the sweat equity necessary to put things in their proper places.
The secret to fending off mosquito attacks is partially to be found in the advice given by practically every municipal government in the world – limit the availability of standing water in which the creatures breed – but more importantly to be found in limiting the spaces in which mosquitoes are comfortable. Yes, the mosquito has a life cycle, and interrupting the larval stage of that cycle will reduce the overall population, but you still need to be prepared for the dangers represented by adult mosquitoes on the prowl, and the best way to do that is to design your living spaces in such a way as to make them feel unwelcome.
What do we mean by that? Well, stop and consider how the mosquito spends its day. A creature that small would rely very heavily on one sense above all others – smell. Sight, they have… but they do not primarily rely on it to discern friend from foe, food from fen. No, they spend their time sniffing out either the sweet, sticky smell of plant nectar (particularly of smoother grasses), or the telltale odor of mammalian perspiration.
There are a few other chemical markers they track, notably carbon dioxide, but the chief thing to note is, it’s their sniffers you need to attack if you want to make them leave you alone.
And the easiest way to mess with their sniffer is to create an environment in which their sense of smell is completely overwhelmed. A pretty herb garden is not just pretty, and it’s not just useful for natural medicines or for culinary delights, it is also your first line of defense against biting insects.
As it turns out, you are orders of magnitude less likely to bit by mosquitoes when tending a bit of garden comprised of pungent plants like rosemary, basil, catnip, sage, lavender, oregano, fennel, anise, mint of all kinds… the smells simply overwhelm the ability of small insects to differentiate plant from person. And if your garden is not monocropped, but is instead a healthier random hodgepodge, even better. The more interspersed the smells are, the greater the effect.
We had read about this phenomenon before, of course, being English literature baccalaureates who don’t’ believe something exists unless it is in print, but experiencing it firsthand has lent us an air of expertise on the subject we might not otherwise have acquired. We noticed several years ago that we were far more likely to get bit in the backyard rather than the front. Numerous experiments reduced the possible number of variables to an acceptably low level to allow us the rather novel conclusion that, by jove, those organic gardeners know what the heck they are talking about.
The usual approaches to the art and science of repelling mosquitoes, of course, are the familiar bug sprays (both those designed to kill and also those designed to repel), in addition to the use of excluding or filtering spaces with screens and netting. The limitations of these approaches are telling – sprays designed to kill end up poisoning more than just the bugs being targeted, while sprays designed to repel end up wearing off (particularly in water); and screens and netting, of course, limit your movement in addition to the movement of the bug – plus, once a hole in your armor is found, the bugs will simply pour through in an unstoppable wave.
The advantage of smelly herbs is that they are there year round (particularly the perennials, such as rosemary, lavender and oregano), and just so long as you plant enough of them all around your yard, they are effective all the time, everywhere, rain or shine. If you happen to have a backyard pool, the effect doesn’t wear off after a dip, either.
And then there is this ancillary factor – we think of mosquitoes as “blood suckers” but the truth is that mammalian blood is only one part of their diet; mosquitoes mostly thrive on nectar from their favorite plants. A grassy field is their favorite abode (watch a squirrel or rabbit run through an open expanse of unmown grass and see the midges fly up from the ground if you want visual evidence). By replacing their natural roosting and foraging grounds with pungent herbaceous plants which provide neither food nor shelter, you can reclaim your territory, enjoying it more on every level conceivable.
There are other advantages to this approach as well, most notably the idea that interspersed herb beds are an excellent exemplar of the forest gardening approaches favored by permaculturalists. Edges are the microecological hotspots, and permanent herb gardens form an exceptional intermediate layer in this multilevel canopy approach to gardening.
We get requests for advice from all over, and one of the more common (and eternally surprising) questions is “How do you keep your rosemary from spreading too much?” The answer, of course, is “Why would we want to stop it?” As far as we are concerned, the rosemary, lavender and fennel can spread as far as they like. Not only do we enjoy the smells…. we know from hard earned experience that mosquitoes don’t.
One final note, about that standing water idea. We have heard numerous people comment on our rainwater collection ponds, saying they would be too nervous about mosquito control to attempt something of the sort. This is a common misconception – the “dangerous” standing water to be worried about is in open containers – old tires, uncovered buckets, clogged gutters and the like. As with so many things, manmade structures are the worst danger – places where mosquitoes might thrive, but none of their natural predators can get at them.
In a natural setting, there are few places less hospitable to mosquito larva than a well tended garden pond – in addition to natural predators such as fish, dragonflies, turtles, lizards, frogs, crayfish, and gude kens wha else, a pond tended by a careful gardener experiences enough maintenance that any mosquito infestation can be readily observed – and dealt with. Baccilus thuringiensis dunks are available at practically every garden supply store, and even these may not be necessary, provided enough natural flora and fauna exist to keep larvae in check.
And, as it turns out… our ponds are not the source of the few mosquitoes we see each year anyway. Scientists have a word for the nesting preference of the truly dangerous mosquitoes – “phytotelmata” is a fancy word for “natural reservoirs on plants” and it is here that the mosquitoes carrying disease are most likely to be born.
Water standing in the stumps of trees, or in standing water in a clogged gutter, or in open buckets, old tires lying around with water in them, or open sewer drains are far more likely to be the cause of a rampant mosquito problem than ponds, creeks or even drainage ditches. This is both because the presence of natural predators is inhibited in these out-of-the-way breeding grounds and also because these places are also the best environments for disease-causing bacteria and viruses to thrive, out of sight from cleansing ultraviolet radiation from the sun, which kills virtually all bacteria and viruses, given enough exposure time.
For those things you can control, like any containers on your own property that you can either remove or clean, or gutters on your own roof that you can clear of debris, the solution is straightforward: clean it, clear it, remove it. For those things you cannot control, like the cleanliness of your neighbors’ yards or gutters, the solution is smelly herbs. Areas of your property where there is likely to be an incursion of visiting mosquitoes should be overplanted with every variety of pungent plant you can imagine – go wild. A rosemary hedge can be a symbol of health and wealth, and a talisman against irritation.
So, as you prepare for summer, you can either get ready to smell like deet, or you can take Myrtle’s advice, and decide to smell like a lovely bouquet of mint, lavender and rosemary. Our approach is more pleasant, we believe, but to each their own.