If semen or any other type of impure substance smudges on clothes or bedclothes, you need to clean it. You don’t need to wash the whole clothing in order to clean them. It will be enough to scour or scrape it if the semen is dry. If it is wet, washing the soiled area will be enough. It is not necessary to perform additional actions to clean them.
Hadiths on this subject are as follows:
Narrated Aisha (r.a.):
“I used to wash the semen off the garment of The Messenger of Allah (p.b.u.h.), and he went out for prayer in that very garment and I saw the mark of washing on it.” (Bukhari, Ablution 64, 65; Muslim, Purification, 108, (289); Abu Dawood, Purification 136; Tirmidhi, Purification 85, 86; Nasai, Purification 187, 188).
Another narration of Muslim is as follows:
“A person stayed in the house of Aisha and in the morning began to wash his garment. Aisha said: ‘In case you saw it (i. e. drop of semen), it would have served the purpose (of purifying the garment) if you had simply washed that spot; and in case you did not see it, it would have been enough to sprinkle water around it, for when I saw that on the garment of the Messenger of Allah (p.b.u.h.). I simply scraped it off and he offered prayer, while putting that on.’ ”
Said Aishah (r.a.), “I used to scratch the semen off the Messenger of Allah’s (p.b.u.h.) clothes if it was dry.” (Muslim, Purification, 105, 109, (288, 290))
“Yahya related to me from Malik from Hisham ibn ‘Urwa from his father from Yahya ibn ‘Abd ar-Rahman ibn Hatib that he had set off for ‘umra with ‘Umar ibn al-Khattab in a party of riders among whom was ‘Amr ibn al-‘As. ‘Umar ibn al-Khattab dismounted for a rest late at night on a certain road near a certain oasis. ‘Umar had a wet dream when it was almost dawn and there was no water among the riding party. He rode until he came to some water and then he began to wash off what he saw of the semen until it had gone. ‘Amr ibn al-‘As said to him, “It is morning and there are clothes with us, so allow your garment to be washed.” Umar ibn al-Khattab said to him, “I am surprised at you, ‘Amr ibn al-‘As! Even if you can find clothes, is everybody able to find them? By Allah, if I were to do that, it would become sunnah. No, I wash what I see, and I sprinkle water around what I do not see.”‘ (Muwatta, Purification,83)