I'm in a strange place to be trying to answer your question, the acidic soiled wet PNW, but there are some corrective actions you can take....

Plant low water requirement plants. Acid loving plants are not going to work.

Ordinary garden watering may wet soil to a depth of a foot or so, part being absorbed by plant roots, the rest evaporating from soil surface. Result: the salts are left as residue in the upper foot of soil and weekly watering possibly bringing salt concentrations up to harmful levels.

Leaching is a possibility...a deliberate flooding for several hours. Even though the water used in flooding contains small amounts of dissolved salts, it will pick up salts which are present in higher concentrations (result of months of regular watering in the upper foot of soil) and carry them into lower soil levels below plant roots. In most cases, a single heavy leaching in midsummer, plus normal leaching action of winter rains is sufficient (container plants requiring leaching more often).

You might also look into adding soil correctives, and I'm no expert here, but gardeners using softened water will generally turn to gypsum as a soil conditioner, those using unsoftened water naturally high in soluble salts use sulfur.

Reliable source for plants suitable for western dry gardens:

Here is a link that might be useful: Low water requirement plants

If you are in zone 5 you might want to try Rose rugosa and its hybrids. Rosa rugosa grows wild up the east coast in New England on the beach in sand. These are very low maintenance roses that require no spraying with fungicides.
Many of the hybrids are quite lovely and fragrant.

Tamarix ramosissima is hardy down to zone 2 and parviflora is possibly OK for zone 5.

Orach is possible, if you can provide some shelter.

Oh for goodness sakes....All Tamarix species are noxious weeds and many states are spending millions of dollars trying to eradicate this. They are also illegal/banned in just about every Western state in the US.

Tamarix are pure #^@&ing evil!!!
Never plant one, and kill every one you can find.

Acid loving is not an issue one way or another.

Most junipers including eastern red cedar, ash, birch, live and red oaks are ok with some salt. Black gum, sweet gum, Kentucky Coffee Tree, most cherry, holly, roses, taxodium, osmanthus, viburnum, and some pines. I'm in zone 8, so we use stuff you can't, but when I have more time I'll post a more detailed list.

I have salty well water. And the concentrations can build. Try top dressing with gypsum every year. It is a type of salt, but it will not hurt the plants and will displace the more harmful salts. It can be watered in. It is cheap, and be generous with it. Hope this helps.

Spartina grasses - particularly the "salt marsh hay" species - would be tolerant, but would require additional watering as they need moist soil. They make good ornamental grasses in upright clumps that undulate in the breeze.

Thanks for the info. It seems I see more and more questions about salt tolerant plants here in the West. Probably because more and more jurisdictions are going to a secondary water source for yard irrigation rather than spending the millions it takes in developing culinary water. I've also been told that drought tolerant plants often times are salt tolerant as well, Is this true?

tamarisks? They are a sticky subject. In some places they are as invasive as all heck and should not be planted. If you are even considering planting a tamarisk or for that matter any other plant known to be invasive anywhere you should ch4eck with your local, state/provincial, and federal agencies and their databases to see if it is listed on an invasive plant list or noxious weed list for your area. If it is don't plant it.If not but it is listed on one for an adjacent town/city or state/province with similar climatic enviromnmental comnditions to yours dont plant it. Tamarisk is not drought tolerant the way most poeple suppose. It has deep penetrating roots that tap into the water table and drain it making the area less habitable for wetland and marginal species. Where it is invasive it crowds out native plants and damages and even destroys whole local ecosystems. There are better plant choices then tamarisks for salty soils.