Wash window sill off thoroughly before putting your plants back, which I would do right away. If the plants are infested, I would think that it has already happened, and you'll just have to keep up a careful washing and rinsing routine. One treatment won't keep the little critters gone, lol. But regular swishing in plain water will discourage them. Treat ALL of your plants, by the way. Spider mites are very easily spread from plant to plant by handling, misting, and their own traveling methods.

I'd be very wary of the kind of soap you use on your plants. Many dish detergents can cause quite a bit of foliage damage.

research the egg development of the demon ...

and continue care for at least twice as long ...

meaning .. presume one of the vermin laid a handful of eggs on you plants .... and the windowsill ...and presume that each one is vaiable.. and presume that you have to kill them all ...

so if they hatch in 30 days ... you have to continue for at least that long .... if your plants were NOT eating plants.. i would suggest a systemic cure for your problems ...

then consider whether it is cheaper and easier to destroy all the plants and spend 20 bucks to start fresh .... after leaving the house empty of plants for a few weeks to make sure all possible eggs have been removed.. or hatched and died for lack of food ...

consider learning about growing plants under common shop lamps indoors ... its not all that expensive .... and could greatly increase your ability and space .... in the hosta forum there are loads of posts on growing hosta seeds indoors all winter long .... and loads of people grow african violets under such setups ... go to each forum and use the SEARCH button to search for such topics ...

finally ..... learn about sterilization of soils at the link below .... and always start with fresh sterile soil when growing indoors... and do it yourself no matter what the seller says ... a new plant should be repotted immediately .. and as you now know .. isolated for a period of time ... a lot of indoor problems ... one way or another.. start in the soil ...

good luck
ken

Here is a link that might be useful: sterilize your soil ...

As fond as I am of Ken, I do need to say that I know of one person in my whole personal and professional experience that has regularly (or even EVER) sterilized their potting medium at home. His name is Ken. ;-)

You should not consider a systemic insecticide for the spider mites for two reasons. One is that systemics are not intended for edible leaf crops such as herbs. Second is that the active ingredients in systemics are very hazardous, even for those listed for indoor use. The exception would be Neem, which has systemic qualities and is highly regarded for the control of spider mites.

Spider mites can be a pain in the neck to control once an infestation has been allowed to take over, but not impossible with regular rinsing and (perhaps) Neem applications.

hey rhizo ....

thank god ken didnt have a computer when the dredded bugs took over the whole house one year.. 20 years back ... i had to go to a vet to get recommendations for indoor bug bombs to get rid of them ....

thereafter i learned that most problems are brought in the soil of house plants ... you can clean what you can see on the plant.. but it isnt going to make a difference if there are 2 billion eggs in the soil ... so it came to be that all new plants were soil drenched and treated with a systemic ... but i grew no plants that i ate ...... and all repotting was done in sterilized soil.. no matter how sterile the seller claims it to be ...

in this case.. it would be easier and cheaper and SAFER to start over ... since they are edible plants ...

let me suggest one further thing ... we think of operating room as sterile.. have you ever considered how sterile nursery propagation greenhouses are .... i would bet a buck ... they are almost equivalent in attitude .... one soil borne plague and you lose a lot of life.. and one heck of an investmet .....

ken

PS: one trick .. if the plants root easily ..... start new cuttings in an isolation area ...... when the roots appear ... sterilize some potting mix ... plant them .. and destroy the originals [out to the garbage truck] ... do multiples of all ... to overcome the odds of failure ... give extras away as gifts ...