Now HERE is a topic with some meat in it! Also one I became hugely interested in, as I live in an area where the 'Skeeters are almost invisible, and yet there are enough to pick a grown man up and carry him away...
(Or so it is said around here)
In my related searches last season I found that there are at least FIVE relatively easy to cultivate plants that are effective at "Producing a scent which repells Mosquitos", and yes Citronella grass
is amongst them. The problem with citronella however, is that it IS a grass which can grow fairly tall - similar to hay (In fact it may get as tall as SIX FEET!), and may not be the most attractive thing to have around your home. ANOTHER concern I have about it, is that in my area there are a lot of hayfields, and if the citronella were to get into those fields, I don't know if it would do bad things to any animals that ingested the harvested hay - so there is that to consider as well.
trees, believe it or not - are listed here and there as having mosquito repellent properties, and are often used for landscaping. But I have to note a caution here as well! Many people are allergic to pine tree sap, and they also produce a lot of fallen needles and other refuse that could become a problem in some settings. They also grow fairly large, but at the same time these are good trees for holding back soil erosion on banks and so on.
~Now we come to the more interesting ones:
The spice "ROSEMARY"
contains an oil that repels mosquitos, and is also a very good spice to have around, especially if you like to cook Italian dishes! The down side? Rosemary does not tolerate cold weather. Therefore it is best done as a container plant, which can of course be set out on a patio or deck.
Now here, we have a large and quite attractive flowering plant. I grew some last year that were spectacular - mixed colors that ended up with flowers at least four inches across that looked like a fireworks display in the places I set them. These are best started early, so that they have a chance to become full size as early in the season as possible. There is only one problem: It is not only mosquitos that find their scent objectionable, some PEOPLE do as well!
Marigolds though have an additional benefit in that they also repel a fair number of insects that might otherwise be harmful to your veggies.
Now we come to my own favorite (and these can be quite a trick to propagate, because the seeds are so tiny)
Catnip (NEPETA CATARIA) so named because of it's amusing effect on felines (I've heard it called "COCAINE for CATS"), has a multi-function effect in the garden or near the patio. First and foremost - IT IS RATED TEN TIMES AS EFFECTIVE AS CITRONELLA for repelling mosquitos! YES, citronella, also known as "DEET". Catnip supposedly blows it away in terms of effectiveness...
It will also attract cats, which will in turn patrol your garden areas for RODENTS which I think is a fine thing.
Once the catnip begins to flower - it also does another favor for us, it is AN EXCELLENT "Bee Forage" which means bees will be attracted to it as well, and therefore to your garden, not to mention AWAY from your patio if you place it right.
The best way to start Catnip is in a tall clear plastic cup, with a drainage hole in the bottom, set in a dish or tray so that they can be watered from the bottom UP. Using a large tray - you can start quite a few, and only have to water the one tray
which is cheating, but makes it simple. The reason for a CLEAR cup is so that you can tell if the roots have got too big for the container. You want a tall cup, because if the roots get all the way down to the water level the plants will turn red and their growth be stunted. If you see them begin to turn pink, empty out the water in the dish, give them a day or so, and immediately transplant them either outdoors or into a larger container. I have one now that is over 24 inches tall growing in a window.
Soon as I can, I'll try to post some pictures.
PS: There are also a number of plants sold on the internet that purport to be "MOSQUITO PLANTS" but the jury is still out on whether they do any good or not. Chances are they are a variety of the above