Potted or in ground? The only recourse I can think would be to flush the salt out as much as possible with plain water. It's the same thing they tell you to do for fertilizer salts build-up. If there is no issue with poor drainage, this should help the damage to be minimal.

they are in ground and i am watering themas much as i can in the evening and in late night

ainee, there is hope. The trick is to wet the ground and keep it wet by a slow drip. Roll out the hose to the wet root ball of the plants and "crack" the nozzle just enough to allow a slow drip
The water has to "remain" in the soil mass to dissolve or dilute whatever salt is present. It must leach downward. If the water runs off too quickly, it will not accomplish this; and you will end up wasting a lot of water.
Inspect the youngest (tip) part of the plants daily to observe if the new leaves are wilting. Do this inspection at daybreak when the plant cells should be most turgid.
I would pay particular attention to the roses. The salt tolerance of the many varieties is quite variable - they tell me.
The West Indian guava (Psidium guajava) is pretty salt tolerant.

thanks ronalawn82 for the detailed answer i am watering them at night to reduce water evaporation weather is on my side lots of dew in the morning and the soil is muddy and is retaining water because there is a weak sunlight

Gypsum will provide the chemistry needed to allow all traces of sodium to leach away from the root zone. The molecular composition of the gypsum particles, calcium sulfate dihydrate, grabs onto the sodium chloride molucules, preventing uptake by the plant and enabling leaching.

This will occur both in real soil in situ and in containers. When I lived and worked in the coastal regions of S. Carolina, I observed that the golf courses in the region, hundreds of them, would order tractor trailer loads of bagged gypsum to spread over the expensive real estate of the golf course when the water table levels introduced sodium into the soils.

I also saved my small (11 acres) container nursery when, during a three year drought, my well water turned salty. On the advice of my consultant, my staff and I top dressed every container with gypsum. I observed a complete recovery of my seriously damaged nursery stock.

Gypsum can be found where fertilizers and agricultural supplies are sold. I like pelletized gypsum the best. Anyone who has soils exposed to rock salt over the winter shoud be using gypsum to mitigate the damage that the sodium can do to soils and plants.

rhizo_1 thank u very much for the detailed answer, a little more info if u can spare the time i already have plaster of paris in my inventory if i am not wrong this will do the trick and wont it make the soil hard as it is a binding agent

No, you must not use plaster of Paris. The processing of the gypsum alters it greatly.

3 tablespoons in 6 liters, sprinkled onto several mature plants?

It's not going to kill them. Just water them thoroughly.

Don't start dumping more stuff onto them trying to correct the error - just water them like you usually do.

If you don't have ALL your containers labelled, please do it NOW. Just slap a piece of making tape on the jar and write on it with a permanent black marker.

lazygardens nope i watered it in the roots direectly and yes they are mature more than 6 years old the roses and guava tree is 20 years old