Essential tips to help identify what's wrong with your houseplant and how to fix it   

With shorter days and cooler temperatures, the winter months can prove tricky for houseplant maintenance. Issues like overwatering, lack of humidity, and cold draughts can all wreak havoc on our precious indoor plants. But there are a few small adjustments you can make to help your plants stay healthy throughout the colder months, placing them in the best position for ample growth when spring comes around. We’ll take you through indoor plant care for winter to help you master the process, taking away any stress and leaving you to thoroughly enjoy your love for growing houseplants.

This troubleshooting guide is easy to put into practice offering simple solutions to common problems with houseplants in winter.

Common houseplant problems in winter and how to fix them: 

Overwatering your houseplants

One of the main challenges plant growers encounter is overwatering. Over summer you’ve been happily watering your plants to a consistent summer watering schedule which they love, because they’re thirsty and the sun and heat is stronger. But as the temperature cools it can be easy to go on autopilot and continue to water your plants to this schedule and with little adjustment. During the colder months of winter the moisture in the soil will not dry out as quickly, resulting in water sitting at the bottom of the soil and creating a very damp environment around the roots. This will leave the plant roots sitting in moisture with the roots unable to take up any more of that moisture, and ultimately leading to mould build-up and root rot. 

Signs you’re overwatering your houseplants in winter 

What is root rot? 

Root rot occurs when the soil remains wet for too long and oxygen becomes depleted, preventing the plant from absorbing essential nutrients it needs to survive. This is commonly caused by watering too frequently – a common problem over the winter months – or from compacted soil or poorly draining soil. 

Signs to look out for to identify root rot/ how to identify root rot: 

Drooping leaves even though the soil is moist – often you will start to see your plant’s leaves droop and eventually the stems will lose their turgid shape and start to almost “keel over”. The stems can also feel soft and mushy to the touch. The top leaves may also start to turn brown because the nutrients are not being absorbed adequately. If you remove your plant from its pot you may see brown/black roots that are soft and sometimes look swollen and this is a key indicator that your plant has root rot.  

What to do if you suspect your plant has root rot:

Cut away the rotting roots and leave the plant to breathe. Then, repot it into fresh, aerated fast-draining soil and let it settle. Place the plant in a spot where it can get additional sunlight and ensure the soil fully dries before watering again. Carefully observe your plant, removing any dead leaves as it tries to recover. 

Mould growth on your houseplants

Another common occurrence caused by overwatering is mould growth, typically seen on the surface of the soil or spreading up the stems. It occurs due to high levels of moisture and poor air circulation and can be a problem for houseplant gardeners during the winter season. Often it looks either powdery white or fuzzy white-grey. 

Signs to look out for/ how to identify mould growth: 

If the mould is forming on the soil try sprinkling cinnamon on the surface as this acts as a natural fungicide. You want to dry out the soil as much as possible to prevent the mould from spreading and to rebalance the moisture levels in the plant’s soil. 

Understanding how to counteract the drop in humidity and subsequent increase in hot, dry air

This is another key problem for many households in the UK during winter months. Your heating is switched on often and regularly, gradually drying out the air and reducing humidity levels in each room. So whilst the temperature range should be ok for your houseplants, the changes in humidity could prove stressful for them, and as a result your houseplants may start to develop crispy, browning leaves. 

This is where plant care throughout winter can become tricky because soggy, damp soil should be avoided but equally the dry atmosphere caused by central heating needs to be counteracted to ensure your plant receives the right amount of moisture. If you’re finding it difficult to measure humidity and your plants are struggling because of this, try buying a humidity monitor to accurately measure the atmosphere and make small adjustments this way. 

How to counteract low humidity, dry air during winter

Your plants will develop crispy, browning leaves, or they may start to curl or shrivel if the humidity is too low. Clustering your houseplants together can improve humidity through the natural process of transpiration, producing a humid microclimate for them. In addition to this, you can gently mist your houseplants, but be careful not to overmist, you simply want to reintroduce a small amount of moisture into the air. Alongside this you should check for adequate ventilation to encourage air circulation. Finally, try filling a tray with pebbles and water and place it next to your houseplants. This will slowly release moisture into the air, helping them to retain water levels. If you are still struggling to prevent your houseplants from drying out then you may want to consider using a humidifier during the winter months.

How to counteract lower light levels during winter 

The winter season means shorter days with less sunlight and this will begin to impact your houseplants, especially succulents and cacti. Try rotating your houseplants by moving them closer to a window or sill. You may even find houseplants that typically enjoy a mixture of shade and light during summer benefit from a brighter spot in winter, so it’s worth running some careful trial and error. 

Some final points on general houseplant care during winter

Take care not to overprune your houseplants when they are in their dormant state as they still need an adequate number of leaves to continue to photosynthesise. The general rule of thumb here is to prune no more than one third of the plant’s foliage. And only use fertiliser if your plant is showing some growth, and always use a diluted solution. 

With thoughtful adjustments, winter houseplant care can become a straightforward task. Paying attention to humidity levels, light exposure and air flow will not only protect your plants through the cold months but also set them up for strong, healthy growth in spring. Similar to the growth period, careful observation, small adjustments, and patience are essential to achieving year-round success with your houseplant collection.