How to care for house plants

To keep your house plants healthy, you’ll need to get the environmental conditions right. That means providing the correct temperature, ventilation, humidity and light levels. In this guide, we explain how to care for your house plants, including advice on watering, feeding, repotting and pest control. 

House plants are an easy way to add colour, structure, texture and a gentle, natural scent to your home. Think exotic orchids and gardenias for scented blooms, succulents for striking structural leaves and lush ferns and monstera for tropical foliage. Browse our collection of house plants to find the perfect variety for every room in your home.

How often should you water house plants?

The frequency with which you water your houseplants depends on the varieties you grow. Cacti and succulents require far less water than moisture-loving ferns, spider plants and begonias. A good way to establish an easy watering schedule is to group your moisture-lovers in a humid space like the bathroom, and your plants that prefer drier conditions in a south-facing bedroom or conservatory. 

As a general rule, allow the top layer of compost to dry out between waterings. Test this by gently pressing a finger into the top layer. If the compost feels completely dry and grainy and the pot is very light, you need to rehydrate it. Place your dry pots on a tray or in a sink and water well, allowing the pots to remain standing in a few centimetres of water for a few hours until they’re heavy and the compost feels moist again. 

During the winter, most of your house plants will become dormant and need far less water than when they’re putting on lots of growth in spring and summer. Read our Christmas house plant guide for more information on winter care. 

Do house plants need feeding?

It depends! Some house plants thrive on supplemental feeding whilst others, like carnivorous plants, prefer not to have any at all. Indoor plants like cacti don’t need feeding, but will grow vigorously and produce more flowers with extra food. Remember that acid-loving houseplants like gardenias need an ericaceous fertiliser.

If you want to supplement your plant’s feed, remember to stop in November. The plant won’t use fertiliser during the winter. This is when growth slows right down and the plant goes into dormancy. Begin feeding again in spring, using a liquid houseplant feed every couple of weeks until the end of summer.

How to treat pests on indoor plants

If you notice that unwanted pests have moved in with your houseplant, don’t panic! They’re usually harmless, but can turn a display into a bit of an eyesore if left untreated. Here are some of the most common indoor houseplant pests:

• Fungus gnats: Tiny black flies that emerge from larvae in the soil and buzz around the potting mix.
• White fly: Tiny white flies with sap sucking larvae.
• Spider mites: Almost too small to see individually, these sap sucking mites weave tell-tale white webs and look like tiny brown speckles.
• Mealy bug: Tiny sap-sucking insect. The females produce a white cotton wool fluff visible on the undersides of leaves. 
• Scale: Limpet-like sap-sucking insects that cluster on stems with a static shell-like covering.
• Aphids: Tiny green-sap sucking insects that make a sticky honey dew. 
• Thrips: Tiny sap-sucking green/black flies.

To prevent harmful infestations from taking over, keep your house plants in optimum health by regularly watering, feeding and giving them plenty of light. Check your plants regularly, looking under the leaves and in the stem and leaf junctures. 

Sap-sucking insects like aphids and scale produce a sticky sweet fluid. Wipe this off leaves and stems with a warm damp cloth. A trick for easy cleaning is to place your large house plants like monstera and ficus in the bath or shower, and give them a go over with a cloth and the shower head. Remember to turn the temperature down and avoid blasting the soil. 

A good ‘cure all’ is regularly spraying your plant with soapy water. Dish soap works well here. This smothers and kills infestations of aphids, spider mites and scale. These tiny insects can all be scraped off the plant using a fingernail or cotton bud. Neem oil is also effective when sprayed onto sap-sucking pests. 

Prevent fungus gnats by covering the soil in the pot of your houseplant with decorative stones. This stops the gnats from accessing and laying eggs in the top surface of soil. Reduce your watering too. These pests love wet soil, and their presence can be an indication that you’re overwatering. 

If your plant is heavily infested, snip off the worst affected leaves and dispose of them in the household waste. In extreme cases, it might be worth starting from scratch with a brand new plant. 

How do you know when a house plant needs repotting?

If you can’t insert a finger into the edge of your houseplant’s pot, it’s time to repot. Most house plants need soil to retain moisture for the roots. A few, like moth orchids, prefer to have their roots exposed. Here’s what you’ll need to repot your houseplant:

• Houseplant compost
• Perlite
• A new pot, slightly larger than the old one
• Plastic sheet/tray to catch soil

When you choose a new pot, aim for one that’s only a few centimetres larger than the current one. It’s important to provide space for growth without swamping the roots. Slightly tighter pots may also help anchor the plant and keep it stable. 

Mix your houseplant compost in a bowl with a few generous handfuls of perlite. Lay down the plastic sheet or your tray and gently tease the plant out of its pot. If it’s tricky, then massage the outside of the pot to free up the roots. Tease the old soil away from the roots. Put a layer of new compost into the new pot and place the plant inside, filling snugly with compost to cover the roots. Water well to hydrate the soil. 

How to revive a neglected house plant

If your houseplant is looking a bit worse for wear, it may need a little TLC to bring it back to full health. Here are a few common warning signs and some easy solutions:

• Floppy plant. Check the soil. If it’s very dry to the touch then it’ll need rehydrating. Incorrect watering is the most common cause of unhappy house plants. On the flip side, floppy foliage that comes away from the base of the plant easily indicates that you are overwatering. Allow the soil to dry out and then adjust your watering schedule.
• Leggy with pale foliage. Give your plant more light. This is a sign that it’s reaching out to find sun to produce food. Check the light that your houseplant should be getting and move it into a brighter windowsill.
• Small leaves and sickly, leggy looking growth. Your plant might be hungry. Use a balanced houseplant fertiliser every couple of weeks. Replace the top third of the potting mix with fresh compost. If you think the plant is a bit tight in the pot then it could be a good time to repot. House plants get all their nutrients from the soil they’re in so it’s important to make sure they’ve got everything they need.
• Brown, crinkly leaves. You need to move your plant into a cooler, moist environment. Avoid keeping your plant near a radiator. Ferns are best in bathrooms where the steamy air keeps their delicate foliage fresh and green.
• Sudden dieback of top growth. If you notice any sudden wilting there could be a problem in the root ball. Fungus gnat larvae and vine weevils like to nibble on roots. Remove the plant and wash the soil away from the roots using a kitchen tap. Throw away the soil (don’t reuse it!) and clean the pot well in hot soapy water. When the roots are clean and free of the contaminated soil, use a new potting mix to replant.

You’ll find lots more tips and tricks in our best expert advice on how to grow houseplants. And if you have pets, be sure you check out which houseplants are pet-friendly in our helpful guide.

Lead image: Cymbidium Sarah Jean gx ‘Ice Cascade’ from Suttons (©Branded Garden Products) 

Last Updated on September 5, 2024 by Suttons Horticultural Team