Ruling on putting flowers and plants in the bathroom
Question

                What is the ruling on putting plants like flowers and foliage plants, or even tree seedlings, in bathrooms for any reason, whether that is for decoration or otherwise?.
Praise be to Allah.There is nothing wrong with 
    putting flowers, plants and tree seedlings in bathrooms, so long as there is 
    no extravagance or waste involved in that, both of which are blameworthy. 
    Allaah says (interpretation of the meaning): 
“And let not your hand 
    be tied (like a miser) to your neck, nor stretch it forth to its utmost 
    reach (like a spendthrift), so that you become blameworthy and in severe 
    poverty”
[al-Isra’ 17:29].
This is a prohibition on 
    both miserliness and extravagance. 
And Allaah says 
    (interpretation of the meaning): 
“and waste not by 
    extravagance. Verily, He likes not Al‑Musrifoon (those who waste by 
    extravagance)”
[al-An’aam 6:141] 
“And give to the kinsman 
    his due and to the Miskeen (poor) and to the wayfarer. But spend not 
    wastefully (your wealth) in the manner of a spendthrift.
27. Verily, the 
    spendthrifts are brothers of the Shayaateen (devils), and the Shaytaan 
    (Devil‑Satan) is ever ungrateful to his Lord”
    [al-Isra’ 17:26, 27]
Extravagance means spending 
    too much money on permissible things, and waste means spending money on 
    things that are inappropriate. 
Al-‘Askari said: 
It is said that waste means 
    spending money on things that are inappropriate and extravagance means 
    spending too much on things that are inappropriate. 
In other words, 
    extravagance means overstepping the mark in spending money, and waste means 
    spending it inappropriately, which is worse than extravagance. Hence Allaah 
    says:  “Verily, the spendthrifts are brothers of the Shayaateen (devils).” 
And it was said that 
    extravagance (israaf) is not just in terms of money, rather it 
    applies to everything that is done inappropriately. Do you not see that 
    Allaah described the people of Loot as being extravagant because they put 
    their seed in a place that is not for tilling. Allaah says (interpretation 
    of the meaning): 
“Verily, you practise 
    your lusts on men instead of women. Nay, but you are a people transgressing 
    beyond bounds [musrifoon] (by committing great sins)”
[al-A’raaf 7:81]
And He described Pharaoh as 
    being extravagant, as He says (interpretation of the meaning):  
“verily, he was arrogant 
    and was of the Musrifoon (those who transgress beyond bound in spending and 
    other things and commit great sins)”
[al-Dukhaan 44:31]
Then he said: 
From these texts we learn 
    that extravagance (israaf) is of two types: haraam and makrooh. 
The first kind includes 
    wasting money etc on things beyond the norm. 
The second kind includes 
    wasting something useful for no purpose, such as pouring away what is left 
    of a drink of the water of the Euphrates etc without putting it back into 
    the water. End quote from al-Furooq al-Lughawiyyah, p. 114-115. 
See also Fayd al-Qadeer 
    (1/50) and al-Mawsoo’ah al-Fiqhiyyah al-Kuwaitiyyah (4/176). 
Examples of extravagance 
    include: buying something decorative for hundreds of riyals, because 
    adornment is allowed but paying a lot of money for it is blameworthy 
    extravagance. 
An example of waste is 
    buying something that is of no value or that will not last, for a large 
    amount of money. 
This, like the example 
    given above, comes under the heading of wasting money that is forbidden in 
    Islam: “Allaah hates three things for you: gossip, wasting money and asking 
    too much.” Narrated by al-Bukhaari (1477) and Muslim (593). 
Conclusion: we must beware 
    of both things and realize that wealth is a blessing that should be guarded; 
    we will be asked about this wealth tomorrow: “From where did he earn it and 
    on what did he spend it?” as it says in Sunan al-Tirmidhi (2416) from 
    the Prophet  (peace and blessings of Allaah be upon him). 
We ask Allaah to keep us 
    safe by His bounty and grace. 
And Allaah knows best.