Gardening expert shares 2 reasons a peace lily has mottled leaves - and how to rescue them

Having bought the peace lily houseplant at the beginning of this year, it was disconcerting to see the leaves taking on a spotty appearance as of late.

Could the peace lily thrive elsewhere in the home? Is there a problem with my watering schedule?

Asking Graham Smith MClhort, a horticultural expert from LBS Horticulture, what could be wrong with my peace lily houseplant, he delivered the answers.

"Typically, yellowing peace lily leaves that look mottled can be a sign of nutrient deficiency," he said. "A lack of nutrients such as nitrogen, iron or magnesium can cause the leaves of the plant to turn yellow."

So what is the solution? "You should try providing it with a small amount of liquid fertiliser," Graham advised. He added: "If the fertiliser does not work, repotting the plant into new soil may help."

Another cause of mottled leaves can be because of the water you are using to hydrate the plant.

"Water quality can also turn the leaves of a peace lily yellow, as it may absorb the minerals present in tap water," he said; this was an aha moment for me.

Normally, knowing my tap water has a high calcium content (i.e. it's hard water), I boil it first, then let it cool down before I water my plants. Most recently I did just water my plant from the sink, so that would have done it.

Graham recommended other people facing a mottled-looking peace lily to test out purified watering. He elaborated: "Even though they are not usually picky plants, it can be worth testing out purified water when watering.

"Spotted or yellowing leaves can also indicate overwatering, especially if you notice that the plant is still soggy a few days after you have watered it. You should let your plant dry out completely, then return to a watering schedule."

He added: "If the roots of the peace lily look like they have root rot, remove any mushy roots and repot your plant."

As for any leaves that have turned yellow, it's "unlikely that they will return to green again".

"They have lost too much chlorophyll," said Graham. "However, once the plant is back to its usual health, it will regrow new leaves in the next season."

Graham emphasised that it's important to remove yellow leaves, "as this will help the plant to redirect its energy towards the remaining healthy leaves".

As for what I'm going to do, I'll take Graham's expertise on board and first take off the yellow leaves. Then I'm going to make sure the peace lily plant isn't suffering from root rot (and to sort that out if it is).

Next I am going to revert back to my watering schedule where I boil the water first, before watering the plant, and a fertiliser is a must.

I may even treat my peace lily to a more spacious pot – and, let's be honest, treat myself to a new decorative pot.