Dog Gone, Nasty Skunk, Dog-B-Gone, Scaredy Cat, Dog Be Gone, Dogbane, Pee Off, and a patented name (similar word for Pee)-Off Plant, and Dog Bane were just some of the names I found for the plant I purchased to make up one of the four, so that I could get four herb plants for $16AU.
Which ever way you look at it, cats and dogs are not welcome. However, I have read, that it is not 100% . But if the 99% works on some of the dogs around here, it may just be worth planting with the lavender and rosemary on the side verge.
The scent of the crushed leaves is pungent, but I don’t think unpleasant. H said the scent reminded him of the sea or walking amongst the sand dunes.
“Fleshy leaves with a distinctive aroma, said to repel dogs (& some people!)” says Highland Way Herbs.
Herb Robert says; “Not all dogs are affected by this plant, but it has been shown to be effective with most.”
Dogbane (Coleus cannis)
I tend to agree with Ginny’s Herbs; “It has a smell you either like or hate, which is said to repel dogs. The flower is purple, not unlike a lavender flower, most attractive.”
Montburg Gardens in Victoria, Australia has Coleus Cannis listed in its “Plants extensively drought tolerant”, which is the most compelling reason for me to include it the side verge planting
The specimen that I got for my $4 looks to have been a prized possession of the nursery as it is root bound and the top soil is covered with moss. But I think I may be able to propagate another dozen plants immediately, which if I do, it will have been a good buy.
dilettante 
Do you know where I can buy a Plectranthus (piss-off plant) in America? Have only been able to find them in Canada & shipping & handling is far too expensive.
I’m in Western Australia so cannot assist with local knowledge, but I have found that Dave’s Garden provides helpful information and there are often links to suppliers, mostly Canada and USA.
I wasn’t aware that Plectranthus was also used to deter dogs and cats. The plant that I have is Coleus Cannis. It was located in the herb section of the plant nursery.
If you don’t find an answer at Dave’s Garden, then you may be able to try the You Grow Girl forums or Folia.
Note: I don’t usually bother to look at obtaining plants outside Western Australia as our state quarantine regulations in Western Australia are very strict.
they sell it in kerbys plant nursery in brandon, fl
Dogbane or Dog Bane is know to be poisonous in the Western United States. Don’t let any kids near the stuff, also stay away from oleander. I had a dog almost die from eating one of the flowers. Both are common and few people know it but can kill you.
@Aaron
Very few dogs get to stray. As a ‘rule’ they should always be on a leash. So I don’t feel that planting Dogbane around a power pole is going to be a problem. If children are going to be allowed to start munching on the foliage around a power pole where the dogs have peed, then I think the parents have a lot to answer for!
I live in Western Australia, too, and just planted several Coleus Cannis close to my Olive Trees which my son’s bulldog pup has taken a liking, too. Them and my sprinklers. To be honest, I think she’s just trying to bury bones so, in order to deter me from burying HER, I’m giving the plant a go.
I haven’t planted (yet!) the many plants that have grown from cuttings that I have taken. Another blog visitor/commenter stated that the plant is poisonous to dogs. However, my understanding is that many plants are poisonous to animals. That is, if they are stupid enough to eat them!
Canadian source -. Try RICHTERS in Ontario for plants.