Why are your Watermelon Peperomia leaves curled, cracked and splitting? (and how to fix them)
Do your Watermelon Peperomia leaves curl and crack? Same! Here’s what I did to fix mine and the 5 common causes to help you fix yours too…
#1 Your soil is too dry.
Watermelon Peperomia retain water well in their leaves and stems, but being scared of overwatering means you might be underwatering (hands up on this one for me, I was definitely guilty of this at first).
Sure, let the soil dry out on top, but not all the way down! Left too dry for too long, Watermelon Peperomia leaves can droop and curl to conserve water. Remember water, light and heat go together. Kept in a bright, warm spot (which they love), they need watering more frequently than you might think. Aim to maintain the soil lightly moist.
If in doubt, get a water meter to check moisture at root level (a few options below). Those colour-changing Sustee water meters are fantastic if budget allows. They're small and stay put in your soil, changing colour from blue to white when it's time to water. But if you want to save your pennies for your plants (I'm all about that), get yourself a cheap 3-in-1 analog water meter that you can move from plant to plant, or a digital water meter you can also shift from plant to plant, that flash a different colour depending on how moist the soil is.
#2 The air is too dry.
If you’re not underwatering, dry air could be causing those cracked, split edges. You don’t need to go overboard, as too much water or humidity can cause leaf or root rot. Maintaining an average of 40% to 60% is plenty, and the same range most of our tropical indoor plants are happier in.
But before you rush to get your plants a humidifier, you can check humidity using a hygrometer. You should be able to pick up one of those little 2-in-1 gauges, which keep an eye on both temperature and humidity, for around $10 to $15. I stock both digital and analog 2 in 1 mini thermometers and hygrometers in a few colours.
If the humidity often drops below 50%, even a small humidifier will make a big difference (I use the H2O cordless plant humidifiers), and the rest of your plants will probably love the extra humidity too.
#3 Temperature check (highs and lows).
Warm is good when you're a Watermelon Peperomia. But not too hot. Around 18 to 25 degrees during the day, ideally not below 15 at night. Leaves can split, crack and curl if things heat up too much, especially combined with dry substrate or dry air. To keep an eye on those top temps, get your plants one of these mini temperature gauges.
#4 It's too dark.
Bright indirect light is ideal for a happy Watermelon Peperomia. If light’s too low, stems can get long & leggy, new leaves can come in small, leaves can curl, and variegation can change. Try a move to somewhere brighter, but make sure sun won’t directly hit the leaves or you could be dealing with crispy sunburned leaves instead. Ouch.
#5 Calcium deficiency.
This was the final key for my Watermelon Peperomia. I fixed everything else, which definitely helped, but still got small, curled, cracked leaves. So frustrating. I almost gave up on mine. Some leaves had weird, almost deformed shapes too.
Off to Dr Google I went. I tried watered-down milk, then dolomite, but my Watermelon Peperomia was still a problem child (and the dolomite lime played havoc with my soil pH). In the end I found a complete and balanced NPK fertiliser with all 12 essential nutrients, including a nice high calcium level (look for calcium on the label). Wow, what a difference.
If you've tried dolomite, watered-down milk, or other sources of calcium, and didn't see much difference, that might be because your plant's missing the other nutrients. It's no good giving your Watermelon Peperomia crazy amounts of calcium if the other essentials are out of whack, as a deficiency in other nutrients can prevent your plant from absorbing the calcium it needs. Fun fact. Calcium also helps plants handle environmental stress better when other conditions aren't perfect. Win win.
Please don't give up on your Watermelon Peperomia! It is possible to get those glorious big shiny, smooth leaves without curled, split, cracked edges. I really hope these 5 causes help you fix yours like they did mine. Please share with a fellow Watermelon Peperomia lover to help them too :)