Succulents come in a plethora of leaf patterns and arrangements we don’t often see in our common broad-leaved house plants. This is what makes them appealing and many growers even collect out of this world-looking succulents.
One of the best types to start with is the moonstone plant, a tough succulent that will captivate you, not just with its fleshy leaves but with its sensational bloom as well.
What is a Moonstone Succulent?
It originated from Mexico and is described to have a rosette of powdery egg-like plump bluish green leaves (1). This appearance is likened to the “moonstone” and the “sugar almond” hence, the plant goes by these names too.
The plant is low-growing with a height of 10cm and spread of 30cm. The stem is upright at first but as it grows, the weight of the leaves will recline the plant on the ground (2). Over time, it will produce offsets that grow close together creating an attractive congestion of leaves that may look like a mound of pebbles.
What does the Moonstone Flower Look Like?
Sometime in late winter or early spring, the moonstone plant will produce graceful flowers. A long floral stalk will emerge in the middle of the plant bearing a series of fleshy grey-green sepals and several downward-facing red flowers with a yellow center (3).
Can you grow Moonstones Outdoors?
Moonstone plants were originally found in rocky cliffs of Mexico so they can definitely be grown outdoors. Although they will grow just fine on the ground under full sun, the plant cannot tolerate 7°C outdoors and will decline with frost but the plant is hardy and can overwinter indoors (1).
Are Moonstones Toxic to Pets?
The moonstone plant is not considered as toxic to pets and humans. If ingested in large amounts, it may upset the stomach but there is no serious effect. The plant has quite a delicate form so better to keep them out of reach of toddlers and pets.
What are the Best Moonstone Varieties to Grow?
While P. oviferum is already sensational in its natural original form, breeders and cultivators still strive to produce new and more remarkable varieties. P. oviferum f. variegatum has a soft bluish-green to bluish-purple tinge with yellow variegation.
There are pink, purple, green and bronze varieties too. The most popular type is probably a pink moonstone succulent. Under the genus Pachyphytum, some species that resemble moonstones are P. bracteosum and P. ‘Garnet Fudge’ (1).
How to Care for Your Moonstone Plant
Light and Water
The moonstone plant likes the sunshine so make sure it receives at least 6 hours of exposure indoors or outdoors. Although it can survive the intense heat of summer, it is best to shade them during peak hours to avoid leaf scorching. Potted ones should be placed in a windowsill where there is bright light, particularly during the dimmer days of winter (3).
The golden rule to growing succulents is to never give them too much water. For the moonshine plant, it is recommended not to leave droplets of water on the leaves as this will remove the powdery appearance and may invite pests and diseases.
Water the plant from below by submerging the half the height of the pot in water for 1-2 minutes. Make sure the soil is well draining to prevent the roots from rotting (3).
Temperature and Humidity
Pachyphytums are generally tough and are considered hardy in US zones 10a to 11b. But there are limits to the temperatures they can be exposed to. They can survive 10-27°C indoors while prolonged exposure to 7°C and below will eventually kill the plant. The plant can tolerate a high temperature but it needs humidity and good airflow to keep the foliage plump and fleshy.
Pests and Diseases
The moonstone plant does not have serious pests and diseases but they can fall prey to aphids and mealybugs that like to suck and chew on healthy fleshy leaves. Common signs and symptoms of these pests are their presence on the leaves, stems, and soil and the shriveling of the leaves.
Control these pests by spraying with insecticidal soap or manually removing them if there are only a few signs. When it comes to rotting of any part of the plant, it is often caused by too much moisture. Always monitor the amount of water the plant is receiving. When in doubt, give the plant 1-2 more days to dry before watering again.
Propagation and Maintenance
The most common and successful way of propagating succulents, including moonstone plants is through leaf cuttings. Simply twist some of the lower leaves and make sure that they do not tear. Lay them on top of a standard succulent or cacti potting mix in a tray and mist sparingly. Placed in a well-lit and well-ventilated location, new leaves and roots will appear in a span of 3-4 weeks.
Sometimes, when moonstones are positioned in a poorly-lit area, the leaves may prematurely drop and the plant will grow leggy. When this happens, cut the stem of the plant near the base and propagate the leaves.
Place the plant in a better location, allow the stem to callus, and withdraw from watering. After several weeks, a new shoot growth should be observed.
Moonstone plants do not require a lot of attention as long as their light and water requirements are met. Over the years they will develop more roots which may cause the plant to wilt fast and have yellow leaves. It is recommended to repot these plants after flowering to allow the roots to breathe and to replenish the nutrients in the soil (3).
Moonstone plants are normally seen potted individually or in a cluster. Although its beauty can stand on its own, moonstones can be combined with other succulents too and they will surely brighten up any sunny or partly shaded areas of the garden or even a dish garden.
(1) McGowan, A. & McGowan, B. Bulbs in the Basement, Geraniums on the Windowsill: How to Grow and Overwinter 165 Tender Plants. Storey Publishing. 2012. P. 208.
(2) Crassulaceae Network. Pachyphytum. International Crassulaceae Network.
(3) Maguire, K. The Kew Gardener’s Guide to Growing House Plants: The Art and Science to Grow Your Own House Plants. White Lion 2. 2019. P. 144.
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