That isn't watermelon peperomia. That's peperomia frost. They actually like a lot less light. Mine is on the second shelf of a plant shelf and is about 18" from a grow light. It does very well and retains all its frosty color there. I sometimes ignore it for too long and it will wilt. Then I water thoroughly and let it sit in a saucer of water for 20 minutes. Then I dump out the remaining water and let it sit in the sink for a bit to make sure the pot has drained off before placing it back in its home. I suspect yours is either getting too much light or possibly too much water. My suggestion would be to cut off all the ugly leaves. Also cut off all the inflorescenses because they drain energy from the plant. Then put it in lower light. Let it dry completely before watering again. You might want to also try to pull it out of the pot to see how the roots look. Hope this helps.

When leaf margins curl downward, especially if leaves droop abnormally from the base of the leaf to the leaf tip, there is probably an issue affecting root function or root health. The main causal suspects would be over-watering or soil compaction causing an inadequate supply of oxygen to roots, a root infection, or a TDS (fertility) level too high, which can limit water uptake. After 6 months, the plant should be stable in the pot. I would remove the rocks as they reduce the exposed soil surface which reduces evaporative water loss - your friend when you're over-watering. If you're over-watering, there are 2 potential fixes. 1) Start checking the moisture level of the medium deep in the pot, at the bottom, with a wooden tell. More on that below. 2) If the plant is of manageable size, water over the sink, allow it to drain, then put Newton's First Law of Motion to work, draining excess water from the pot. See below. Do check for mites, as the plant looks mighty mitey. You might need a jeweler's loupe or a magnifying glass to see them. Using a 'tell' Over-watering saps vitality and is one of the most common plant assassins, so learning to avoid it is worth the small effort. Plants make and store their own energy source – photosynthate - (sugar/glucose). Functioning roots need energy to drive their metabolic processes, and in order to get it, they use oxygen to burn (oxidize) their food. From this, we can see that terrestrial plants need plenty of air (oxygen) in the soil to drive root function. Many off-the-shelf soils hold too much water and not enough air to support the kind of root health most growers would like to see; and, a healthy root system is a prerequisite to a healthy plant. Watering in small sips leads to avoid over-watering leads to a residual build-up of dissolved solids (salts) in the soil from tapwater and fertilizer solutions, which limits a plant's ability to absorb water – so watering in sips simply moves us to the other horn of a dilemma. It creates another problem that requires resolution. Better, would be to simply adopt a soil that drains well enough to allow watering to beyond the saturation point, so we're flushing the soil of accumulating dissolved solids whenever we water; this, w/o the plant being forced to pay a tax in the form of reduced vitality, due to prolong periods of soil saturation. Sometimes, though, that's not a course we can immediately steer, which makes controlling how often we water a very important factor. In many cases, we can judge whether or not a planting needs watering by hefting the pot. This is especially true if the pot is made from light material, like plastic, but doesn't work (as) well when the pot is made from heavier material, like clay, or when the size/weight of the pot precludes grabbing it with one hand to judge its weight and gauge the need for water. Fingers stuck an inch or two into the soil work ok for shallow pots, but not for deep pots. Deep pots might have 3 or more inches of soil that feels totally dry, while the lower several inches of the soil is 100% saturated. Obviously, the lack of oxygen in the root zone situation can wreak havoc with root health and cause the loss of a very notable measure of your plant's potential. Inexpensive watering meters don't even measure moisture levels, they measure electrical conductivity. Clean the tip and insert it into a cup of distilled water and witness the fact it reads 'DRY'. One of the most reliable methods of checking a planting's need for water is using a 'tell'. You can use a bamboo skewer in a pinch, but a wooden dowel rod of about 5/16” (75-85mm) would work better. They usually come 48” (120cm) long and can usually be cut in half and serve as a pair. Sharpen all 4 ends in a pencil sharpener and slightly blunt the tip so it's about the diameter of the head on a straight pin. Push the wooden tell deep into the soil. Don't worry, it won't harm the root system. If the plant is quite root-bound, you might need to try several places until you find one where you can push it all the way to the pot's bottom. Leave it a few seconds, then withdraw it and inspect the tip for moisture. For most plantings, withhold water until the tell comes out dry or nearly so. If you see signs of wilting, adjust the interval between waterings so drought stress isn't a recurring issue. Newton's First Law For conventional container culture, it's a given that saturated/partially saturated media rob roots of the oxygen they need to function normally and efficiently. At best, soil saturation robs your plants of immense measure of potential in areas like growth, appearance, yields, ….. At worst, plants unable to cope with the strain of drought stress caused by saturated media will succumb to it. This isn't a 'scare tactic, it's a very simple and straightforward observation that will be difficult to disagree with a straight face. Newton's First Law of Motion states that an object will remain either at rest, or in motion at a uniform rate and in a straight line unless acted upon by an external offsetting force. In this case, we will designate the 'object' as excess water in your potting medium. At risk of my being redundant, the 'law' can be seen as a simple statement about inertia, that objects will remain in motion and in a straight line unless a force acts to change the motion. To put the law to work for you/your plantings, you should water to beyond the point of total soil saturation - so the medium has been completely saturated and at least 15-20% of the water you have applied has exited the pot. Unless your soil is purposefully constructed to eliminate all/nearly all excess water, it's extremely probable, when the pot has stopped draining, there will be too much water in the potting medium for the plants' liking. To eliminate this excess water: immediately after a thorough watering, hold the pot in one hand over the sink, lawn, or over-sleeping significant other and move it downward, then sharply reverse the direction to upward. You'll immediately note that a good measure of 'excess' water will “continue downward in a straight line” and exit the drain hole. The sharper the reversal of direction, the more water exits the drain hole. When you have repeated the exercise until water no longer exits the drain hole on the reversal of direction, you will have eliminated all excess water and your plants will regard you with a newfound sense of awe. Al

Probably thrips. Very unusual to see them on a Pep. I agree; quarantine it it. The treatment needs to be systemic, because they pupate deep in the soil. I use Bayer Advanced Tree and Shrub at the rate of 1oz. per gal.

is it in pure peat moss??? i dont know what it is.. but i wouldnt grow anything in straight peat ... there arent many things that prefer such acidity ..... tip it out of the pot.. and see if the roots are happy ... snap a pic .... and stuff it back in the pot for now... post us the pic ... what you got away with outdoors.. might not work indoors ... im curious about the greenhouse setup up.. you brought in the house.. if you care to share with us ... ken