Are Braids Haram?
Question

My husband asked me to braid his hair, and I asked him about the ruling on that in Islam. He quoted the views of some scholars about braiding men’s hair – is that correct? I am asking about this not because I don’t believe him, but because I want to know whether there is another opinion, because this is something strange for me.
Praise be to Allah.Is there a reward for letting hair grow?
Letting the hair grow long is not a Sunnah for which the Muslim will be rewarded, rather it is the matter of custom and tradition. The Prophet (peace and blessings of Allaah be upon him) both let his hair grow long and shaved it. He did not say that there was any reward for growing the hair long, nor is there any sin in shaving it, but he commanded men to take care of their hair. 
How did the Prophet braid his hair when it grew long?
Abu Hurayrah (may Allah be pleased with him) narrated that the Messenger of Allah said: “Whoever has hair, let him take care of it.” (Narrated by Abu Dawood, 4163; classed as hasan by al-Hafiz ibn Hajar in Fath al-Bari, 10/368) 
‘Aishah (may Allah be pleased with her) said: I used to comb the hair of the Messenger of Allah when I was menstruating. (Narrated by al-Bukhari, 291)
The hair of the Prophet (peace and blessings of Allah be upon him) came down to his earlobes, or between his ears and his shoulders, or it reached his shoulders. When his hair grew long, he would put it in four braids . 
Anas (may Allah be pleased with him) narrated that the hair of the Prophet (peace and blessings of Allah be upon him) reached his shoulders. (Narrated by al-Bukhari, 5563; Muslim, 2338)
Anas ibn Malik (may Allah be pleased with him) said: The hair of the Messenger of Allah (peace and blessings of Allah be upon him) came down between his ears and his shoulders. (Narrated by al-Bukhari, 5565; Muslim, 2338)
According to a report narrated by Muslim: The hair of the Messenger of Allah came halfway down his ears. 
‘Aishah (may Allah be pleased with her) said: The hair of the Messenger of Allah (peace and blessings of Allah be upon him) came down longer than his earlobes and shorter than his shoulders. (Narrated by al-Tirmidhi, 1755; Abu Dawood, 4187; classed as saheeh by al-Albani in Saheeh al-Tirmidhi)
Umm Hani (may Allah be pleased with her) said: The Messenger of Allah (peace and blessings of Allah be upon him) came to Makkah and he had four braids. Narrated by al-Tirmidhi, 1781; Abu Dawood, 4191; Ibn Majah, 3631; classed as hasan by Ibn Hajar in Fath al-Bari; classed as saheeh by al-Albani in Mukhtasar al-Shama'il, 23. 
Al-Hafiz ibn Hajar (may Allah have mercy on him) said: 
“What is indicated by the hadeeth is that his hair usually came down to his shoulders, and sometimes it was so long that he wore it in braids, as was narrated by Abu Dawood and al-Tirmidhi with a hasan isnad from Umm Hani who said: The Messenger of Allah (peace and blessings of Allah be upon him) came to Makkah and he had four braids. This is to be understood as referring to times when he was so preoccupied that he could not take care of his hair for a long time, such as when travelling and the like.” (Fath al-Bari, 10/360)
Are braids haram?
This is something that was acceptable and usual according to the customs of that time. Customs vary and Muslims may be living in a place where people do not do that, or they regard the one who does that as imitating immoral people, so it should not be done. 
Shaykh Muhammad ibn Salih al-‘Uthaymeen (may Allah have mercy on him) said: 
“There is nothing wrong with letting the hair grow long. The Prophet (peace and blessings of Allah be upon him) had hair that sometimes came down almost to his shoulders. Although in principle there is nothing wrong with it, nevertheless it is subject to tradition and custom. 
If custom dictates that this is not done except by a specific group that is traditionally known to be immoral, then those who are decent and of good character should not let their hair grow long, because it is customarily regarded by the people as something that is only done by those who are of low status and immoral. So the issue of whether men may grow their hair long is something that is permitted, but is subject to the customs and traditions of the people. 
If custom dictates that all people, noble and lowly alike, grow their hair long, there is nothing wrong with it; if it is done only by the lowest of people, then people of honour and status should not do it. No one should respond by saying that the Prophet (peace and blessings of Allah be upon him) – who was the noblest of people and the highest in status – used to grow his hair long, because we can see that growing one's hair long is not a Sunnah or an act of worship, rather it is the matter of following customs and traditions.” (Fatawa Noor ‘ala Darb)
What your husband says about the Prophet (peace and blessings of Allah be upon him) having four braids is correct, but that does not mean that this is a Sunnah for which a person will be rewarded, rather the customs of the people and what they are used to should be heeded. Customs are different now in most countries from what they were in the past. 
Ibn ‘Abd al-Barr (may Allah have mercy on him) said: 
“Nowadays no one braids their hair except soldiers who have long hair; people of righteousness, modesty and knowledge have turned away from this custom, until that has become one of their distinguishing features. Nowadays long hair has virtually become the characteristic of the foolish. It was narrated that the Prophet (peace and blessings of Allah be upon him) said: “Whoever imitates a people is one of them – or will be gathered with them (on the Day of Resurrection).” It was said that it means whoever imitates them in their actions, or whoever imitates them in their appearance. This should be sufficient for you. This hadeeth refers to following the example of the righteous in whatever they do. Growing one's hair or shaving it will not avail anything on the Day of Resurrection, rather what counts will be intentions and deeds; a man whose head is shaved may be better than one who has hair, or a man who has hair may be a righteous man.” (Al-Tamheed, 6/80)
To conclude, we should follow custom and tradition with regard to braiding hair by men, so that the Muslim will not expose himself to people’s mockery and backbiting. 
For more information about braids, please see the answers to questions No. 40329 and No. 128184 .
And Allah knows best.