What is the biggest killer of houseplants? Plant experts reveal the care tip you should never overlook

What is the biggest killer of houseplants? Knowing the answer to this question will save you a lot of time you might have spent standing over a drooping fern or a crispy fiddle-leaf fig in despair.

Now, while you could resign yourself to a lifetime tending to so-called unkillable houseplants, we know that you've likely got your heart on making one of the best houseplants of all time your next plant baby. And we don't blame you one bit, to be honest.

According to the experts, the biggest killer of houseplants is not feeding them and not repotting them when they need it most. While some houseplants like to be pot-bound it will stress most plants and eventually kill them.

'Many symptoms of sad or stressed plants are down to lack of sufficient nutrients (or light!). While plants outside can grow deeper into the soil in search of nutrients, houseplants are limited to the compost in their pots,' explains Kelly Dyer, in-house plant doctor at Patch Plants.

'In reality, most composts only have enough food to keep them going for about 6 months. After that, they require regular feeding with plant food during their growing season – from late spring to late summer – to top them up.'

It's for this reason that repotting is an essential element of houseplant care – knowing when to repot houseplants as well as how to repot houseplants.

'The longer they’re in their pot the more the compost will break down and become compact and if the plant is growing well, then the roots will eventually fill the pot, leaving little room for compost,' says Kelly.

'Repotting into fresh compost should be done at a minimum every 2 years if you feed regularly. This can either be into a slightly bigger pot, or you can trim the root ball down and plant it back into the same pot.'

A note on watering

That all being said, overwatering AND underwatering are the second biggest killers of houseplants.

'There are many reasons why houseplants die but the most likely is to do with watering, and almost always overwatering,' says Ellen-Mary Webster, author and professional gardener.

'Plants are easy to kill with kindness! It’s important to check the label when purchasing a new houseplant and do some research to see how much water your individual plants actually need.'

'Generally speaking, many houseplants may need watering once a week to every two weeks depending on the amount of light, the pot size and temperature. Some will need more and others far less,' explains says professional gardener Ellen-Mary Webster, who adds that 'watering many houseplants more than once a week is almost always deadly!'

'Houseplants will mostly need less water over the colder winter months but can also dry out really fast if the heating is on,' she continues.

'The majority of houseplants (but not all) won’t want to be sitting in wet, cold soil as this will cause the roots to rot, so a thorough watering infrequently, allowing the water to drain out the bottom of the inner pot before putting it back in the outer pot is better than a little water every now and again.'

Of course, now you know the biggest killer of houseplants, you can arm yourself with this knowledge in order to better protect your beloved plant babies from an untimely end.

We guess it's the perfect excuse to treat yourself (and your indoor garden_ to an array of beautiful new pots – as well as a mister for spritzing them and keeping them hydrated (but not too soggy) as and when required.