Try Mint and hope it runs under the fence and grows on their side, too.

As far as a plant that will waft a nice smell (rather than just smelling nice when you stick your nose in it) I like Japanese honeysuckle. I know some people think this is too invasive to grow, but personally I haven't had any trouble with it. It does well in the sun.

How many weeks during the year do you have fighting dog smell in your backyard? You may need more than one kind of plant to cover the time period. And you might end up with the equivalent of spraying scented Lysol in a Forest Service outhouse--good and bad odors combined.

If these are fighting dogs as used in dogfights, the authorities are interested in removing them.

These 4 perennials give a pleasant aroma to our gardens when in bloom. I can smell it from the driveway or across the lawn, so not just up close. In part shade taller plants need staking or can lean against a shrub. All of them I've listed reseed & spread well, so not useful next to more delicate slow growing perennials.

Valerian (6' here, white flowers early summer, reseeds)
Dame's Rocket (tall & weak stems, more so in evening, very late spring through mid summer)
Sweet Woodruff, flowers & foliage (midspring, white carpet of flowers)
fumewort, Corydalis lutea (slug resistant, blue green lacy foliage, yellow flower, reseeding)

fragrant foliage (easy to get starts from friends' gardens)
Bee Balm, Monarda (doesn't tolerate drought)
bigroot hardy geranium, G. macrorrhizum

If you brush the foliage more fragrance wafts through the air. Usually, not fragrant unless touched or up close.

You might prefer a mixed hedge of shrubs for more impact...

Here is a link that might be useful: Portland garden writer recommendations

Are they raising dogs for protection or for actual use in fighting. Please report these people to the police immediately if the latter. Dog fighting is both cruel and illegal. Make it anonymous if you need to.

For the record my favorite fragrant plant would probably be Daphne Odora. It gets my award, tied with Gardenia for strength of fragrance and pleasantness. I think it blooms late Winter/early Spring but I can't grow it here (partner with allergies). There is a hardier Gardenia that might be also good but I haven't tried to grow it.

Your best bet would be harlequin glorybower. Strong, wafting floral fragrance July to September, the time of year when the poop stench is liable to be the most bothersome. Under some conditions the tree can be smelled and enjoyed some distance away, say 100' or so.

Often in stock at a local outlet somewhere in the area in any given year, although with the significant shrinking of tree selections here in recent years maybe not so much now. But you could probably have one shipped here from forestfarm or other out of state supplier.

Artemisia abrotanum in full sun.

For the part sun spot i would get a strong scented cedar. Or the messiest pine you can find (needles drop on neighbor, mask odor at source).

Heck just go for a western juniper.

Thanks for all the great help, and nice ideas, I am making a log of these right now.

As to the strange nature of the situation: yes! they are fighting dogs. he is now, and for more than ten years has been, closely followed by the authorities, who are well aware of his activities, but are not (yet) able to stop him.

as many of you know, this is not uncommon in certain parts of town.

so i very much love the ideas of plants that might go over the fence. And yes I agree, I am hoping to get a sense of when plants are most fragrant, and to choose a set that will, at least, cover dog feces odors for the summertime months.

you guys are awesome and geniuses and I appreciate all your wisdom and experience.

Thanks for all the great help, and nice ideas, I am making a log of these right now.

As to the strange nature of the situation: yes! they are fighting dogs. he is now, and for more than ten years has been, closely followed by the authorities, who are well aware of his activities, but are not (yet) able to stop him.

as many of you know, this is not uncommon in certain parts of town.

so i very much love the ideas of plants that might go over the fence. And yes I agree, I am hoping to get a sense of when plants are most fragrant, and to choose a set that will, at least, cover dog feces odors for the summertime months.

you guys are awesome and geniuses and I appreciate all your wisdom and experience.

My Stargazer lilies are planted near my back door and are blooming right now. The scent is wonderful and since I usually have the patio door open, get to enjoy the scent inside too.

Plectranthus caninus

From Wikipedia, the free encyclopedia

Plectranthus caninus
Plectranthus (coleus) caninus
Scientific classification
Kingdom:
Plantae
(unranked):
Angiosperms
(unranked):
Eudicots
(unranked):
Asterids
Order:
Lamiales
Family:
Lamiaceae
Genus:
Plectranthus
Species:
P. caninus
Binomial name
Plectranthus caninus
Roth.
Synonyms

Coleus caninus
Coleus canina

Plectranthus caninus is a herb in the mint family Lamiaceae,
native to east Africa and southern Asia. Under the name "Coleus
canina", it is sold and marketed as a natural repellent to cats and dogs
(labeled as "Scaredy Cat Plant" and "Piss-off plant"), though no
research currently exists that supports that usage. These plants root
easily from cuttings or from just touching the ground. They like full
sun.

Both the leaves and flowers of the plant are sticky to the touch, and have a mild odour not unlike that of marijuana.

Ok if they can't bust him for dog fighting can't he be reported for having too many dogs or for the unsanitary conditions? Vector control? Animal Control? for the barking?

The fruits of quince (Cydonia oblonga, I'm not talking about flowering quince here) are extremely fragrant. They can hang on the tree for quite some time and perfume the surrounding space from October to November.

In the wet Northwest fruiting quince can be vulnerable to fire blight, so they are best planted somewhere that gets full sun, and pruned for good air circulation before the heavy rains start in October. The variety 'Aromatnaya' is less vulnerable than others.

Fire blight tends not to be a big issue west of the Cascades. In fact, the occurrence, even in commercial orchards, is quite rare and it is seldom seen in garden settings.