I originally wrote this in 2019, and I came to update it. I ended up deleting the entire thing and rewriting it. I didn’t even re-read it. I don’t think I had anything ground-breaking to say about house plants back then.
I’ve also tried to make it easier to read. And linked any relevant articles. Let’s go!
Watering
- Moisture metres work well on dense (i.e. store-bought) soils. I still use one to this day.
- Let plants dry out almost all the way – a 2 on the moisture metre is fine for most plants.
- If your tap water tastes pretty good and doesn’t fur up your kettle too much it’s probably fine for your plants
- Try to water with room temperature or tepid water to prevent shock
- Fancy watering cans tend to spill – I prefer a teapot
- It’s advised that we water less in winter – use the same indicators as you would in summer (i.e. wait till the soil’s nearly dry). Some people’s homes are just as warm and bright in winter, so your plants might keep growing
- Water your plants thoroughly. Overwatering is caused by watering too frequently, not by giving too much water in one go
- Make sure your pot has drainage holes. Rocks in the bottom do NOT help with drainage
Light
- Some houseplants can survive in the dark, but won’t thrive. Stop torturing your snake plants
- If your house is dark, invest in some grow lights. In some cases, LED lights will do.
- Monstera can take bright, direct light if acclimated properly, as can Pothos.
- Plants that prefer low light usually require high humidity and won’t tolerate tap water
- Keeping your windows AND plant leaves clean maximises light
- Plants can live in north-facing windows
- North is the gentlest light, west is the harshest (and hottest)
- Putting plants outside in the shade is often brighter light than inside in a bright window – acclimate plants before putting them outside in the sun by putting them in the shade first and gradually increasing the light over a couple of weeks
- Putting your plant in bright light will help it:
- grow bigger and faster
- fight off pests
- be more resilient to neglect
- Brighter light also dries the soil out faster, so you may need to water more often
Temperature
- Bathrooms are typically too cold (especially in winter for a lot of humidity-loving houseplants
- Hot temperatures can cause your plant to droop
- Hot temperatures can impact variegation – for example Philodendron Paraiso verde needs high temperatures to produce variegated leaves.
- Succulents are extremely cold tolerant, but they need protection from frost.
- Sunrooms/conservatories are often too cold in summer for tropical plants. They can also get too hot in summer, but if you keep on top of watering and make sure there’s enough humidity, they’ll be ok
- Cold shock can cause yellow spots and pitting on the leaves. My Hoya acclimated and recovered (the leaves are still yellow, but didn’t perish) but if you’re moving your plants into a colder room in winter…acclimate them.
- Plants seem happy in the same temperatures as humans. If it’s too hot/cold for you, it’s too hot/cold for them. This is obvs a generalisation, but I think it’s a pretty decent benchmark
Humidity
- Misting is not the same as high humidity, because the water is still in liquid form. It’s more like raining on your plants, which plants do NOT like.
- A humidifier is the best way to increase the humidity in your home
- Low humidity can cause stunted growth and brown spots on the leaves
- Tropical plants that don’t climb (ferns, Calathea, crawling Philodendrons) tend to prefer high humidity, and ill sulk if they don’t get it
- Water quality matters when it comes to humidity, so if you have a picky plant, try putting filtered water in the humifier
- Pebble trays don’t work. Sorry.
- Grouping plants together works a bit (you’ll need a hygrometer to measure), but only in a small room
- Small plants, like fittonia, can go in terrariums to increase the humidity
- Increasing the humidity can help stuck leaves release
- High humidity can increase the growth of aerial roots – great if you want your plants to climb
Repotting
- There’s nothing wrong with store-bought potting mix. If it’s too dense, add some perlite
- a good basic potting mix is
- 4 parts coir
- 4 parts perlite
- 4 parts bark
- 1 part charcoal
- 2 parts worm castings
- If you find that this dries out too quickly, increase the coir and perlite, as they retain more water
- Don’t go up too big of a pot size (max 2 inches unless the plant is VERY established) because it slows down growth (as the plant fills the new pot with roots) and can cause root rot
- There is no need to repot plants when:
- you bring it home from the store
- it has fungus gnats
- it has root rot
- If your plant has had pests or rot, dry the soil out in the sun. This will kill the bugs and you can reuse it.
- Repotting is stressful to plants (it wouldn’t happen in the wild) so be gentle. You don’t need to break up the roots most of the time.
- Those net pots/plugs are unlikely to harm your plant. Remove them if you can (they’re very common in Hoya), but don’t worry about them. The roots will adapt.
- Most plants can grow hydroponically (in just water) but you need them to grow water roots so they can absorb oxygen from the water
- LECA is another option, but there’s a bit of a learning curve.
Cleaning
- Wipe your plants with a microfiber cloth when they’re dusty to increase the amount of light available to them and reduce pests
- Before dusting, spray with water with a drop of castile soap or neem oil (or both) added to prevent pests
- Cleaning is even more important in winter. All that time you would have spent watering but don’t need to? Clean instead
- Makeup-removing clothes (the microfibre ones) are AWESOME. As are dusting gloves.
- You can remove water marks with lemon juice
- Leaf shine spray is fine on healthy plants, but avoid using it on unhealthy ones because it blocks the stomata. Like misting, it’s not the worst thing in the world, but it’s also not beneficial to the plant
- Showering plants is fine, but use cooler water and don’t wet the soil unless it needs watering
- Dry off the leaves in cold weather to reduce the chance of fungal infections
- Foliar sprays for orchids are a great option to spray before cleaning. They usually contain a small amount of nutrients and something to deter pests
- In summer, you can take all your plants outside and spray them down with a hose. Watering, cleaning, and pest removing all in one!
Propagating
- Research how your plant propagates before taking a cutting
- If your plant needs a node to propagate, you need a bit of stem NOT petiole.
- Changing propagation water everyday helps it root faster
- If you don’t have time, try using nutrient water
- If you’re worried about your plant not rooting, layer it rather than chopping and propping.
- You can propagate year round but doing so in spring will mean it roots faster, and you can get it potted up and ready to grow in the heart of the growing season. In winter everything’s much slower (and growth is weaker)
- Dividing a plant (e.g. Calathea, peace lilies, ferns) is literally a case of dividing the plant into all its individual plantlets and planting them into their own pots. It’s really easy, but some plants (peace lilies) will sulk for weeks after.
- Most common house plants are propagated by tissue culture, so one tiny piece of plant can produce hundreds of babies. Garden centres don’t just take a lot of cuttings.
- You can pot water propagations up in soil once the roots are about four inches long (shorter if there are multiple roots
- Keep the soil damp for a few weeks to help the water roots acclimate to soil by misting the top of the soil as soon as it’s dry
Choosing plants
- Plants that grow in low light are always harder to care for than plants that grow in bright light. E.g. succulents are easy to grow IF you put them in a lot of bright light.
- Avoid carnivorous plants if you’re a newbie. Most need very specific conditions
- Only buy plants from the reduced section if you know what’s wrong with them. A lot have root rot; orchids often have mealybugs
- Bigger plants are more expensive but tend to be more established and are less likely to die
- Baby plants are cheap but dry out quickly so require more maintenance. They’re often only recently hardened off from tissue culture
- Check your light and humidity levels before picking plants. If you have an east-facing window and humidity of 60%, that’s good for a LOT of plants
- Monstera deliciosa is a great option for a starter plant. Maidenhair fern is not. My recommendation is Peperomia hope.
- Don’t pick a plant for its flowers when you’re new. Learn how to care for foliage first
- Though if you pick an orchid, I find them easiest keep bare root. Remove all the soil/bark, and keep the roots in a jar. Fill the jar with water once a week (and fertilise every couple of weeks) and dump it out after an hour or so
- Ferns are a pain for newbies AND drop leaves constantly. Wait until you’re more experienced.
Fertilising
- Most house plants come with slow release fertiliser in their soil, so you shouldn’t need to feed them for about six months
- Only fertilise when your plant is growing. If it’s growing in winter, fertilise, but lay off if it’s gone dormant
- I use General Hydroponics Flora mix because you can use it in a variety of substrates. Any fertiliser that’s 10-10-10 is fine
- If you’re keeping plants in water, you need a hydroponic fertiliser, because there are no micronutrients (unlike in soil)
- Overfertilising is difficult to diagnose, but IME usually results in slow growth. As often as every other time you water, or as infrequently as every two months is fine.
- Don’t worry too much about which plants need what fertiliser. They can all go on the same schedule, with exceptions as needed. For example, my Pothos N-joy only gets fertilised once a month – if I feed it more often I get black marks on the leaves
- DIY fertilisers like banana peel usually attract fungus gnats
- Coffee grounds can add a bit of aeration to the soil, but also grow mould (which is gross, but rarely a problem).
- Mushrooms are a sign of fertile soil, but can also be a sign that the soil is too wet
- Fertiliser can be administered in the form of foliar spray if you like
Pests
- Dust attracts spider mites. Clean your plants.
- You will get pests at some point. Stave it off as long as you can by keeping your plant clean and spraying them with neem oil or soap
- Bathing your plant (leaves and all) in hot water (45˚C/113˚F) for 10 minutes kills most pests, excepting a certain type of flat mite on hoyas. It’s tricky to keep your water at that temperature for 10 minutes though.
- I use castile soap in water to spray down my plants. One drop of soap per 250ml of water is plenty.
- Systemic granules are fine, but some pests like thrips can become resistant to them, and they can also kill beneficial bacteria in the soil
- Wiping the leaves every few days can work (just with a damp cloth) but you’ll need to keep up with it for a couple of months
- Isolate plants with pests to stop them spreading and keep an eye on all your other plants
- Tenacious cats will put up with most things. You may have to separate them
- Non-toxic plants tend to be tasty, so keep plants and predators (I have rabbits) separate
- Check new growth and the er, crotch of the petiole/leaf when looking for pests
Miscellaneous
- Kratiste poles are awesome supports for climbers if you can’t be bothered to keep a moss pole damp
- Most climbing plants only grow one stem at once, so you’ll either have to chop and prop to make it bushier, or give it so much humidity it activates more axillary buds
- Coir poles are fine as supports but your plant will struggle to attach to it
- Planks are an option, but they’re heavy so only suitable for plants heavy enough to stay upright
- Moss poles are great, but you need to keep them damp for the roots to attach
- You can reuse nursery pots, and sit them in pretty pots – you won’t need to worry about water on your furniture
- Silica can help strengthen plants – especially variegated ones
- Aerial roots are to help plants climb. They don’t need them, and you can chop them off if they’re unruly
I absolutely love your attitude & knowledge! I have my own Trial & Error Club it started about when the pandemic started. I have bulbs, flowers & a potho. I practically killed it with kindness. Burnt everybody with fertilizer organic, all of them. My fav is the elephant ears. They started as gangbusters then took a turn. Everybody is indoor & I wanted their 1st transplant to be into the Playboy Mansion wrong! Yes the trial & error club flourished with Error. My E Ears have like a boo boo on both stems. I checked hard to no avail did I see or detect movement. My new quest is to find out what’s causing this plight to both ears. I know it’s bad they’re safe living in Hearst Castle but in isolation. If you’ve got an inkling on what it may be Please send us a clue & we will all be in debt to you forever! I’m not in the best locale for my new projects
Northern Nevada. I built 2 outstanding display tables. Rounds, sanded & stained- Mahogany. Yeah I joined the Home Depot Garden club. If the libraries would open I’d be up to my ass & elbows in DIY books. Anywho love your articles & I’m now a proud subscriber . Tracey K.
Oh no! Well, we live and learn. Can you send me a picture of the boo boo (email caroline@planethouseplant.co or message me on Instagram)? I’m thinking scale if it doesn’t move. Well done for building the tables – my DIY skills are terrible, but I’d love to improve!