The heartleaf ice plant is a perennial evergreen herb in the family Aizoaceae, genus Mesembryanthemum. Its stems lie slanting and spreading, 30-60 cm long, branched, slightly fleshy, hairless, with small granular bumps. The leaves are opposite, heart-shaped-ovate, flat, with a sharply pointed or rounded tip bearing a small point, and a rounded base. The flowers are solitary, terminal or axillary, with a pedicel 1.2 cm long; the calyx is 8 mm long with 4 lobes; the petals are red-purple and spoon-shaped; the stamens are numerous; the ovary has 4 chambers.
Growing Methods
As soon as the seedlings emerge, remove the covering, move them to a ventilated spot, gradually expose them to sunlight, and water with a fine-nozzle spray bottle according to the condition of the potting soil. A daytime temperature of 20-25°C and a nighttime temperature of 10-12°C is sufficient. About 25 days after sowing, when the seedlings have unfolded 1-2 true leaves, prick them out. If the midday sun is too strong, provide appropriate shade. When the seedlings put out new leaves, it signals that they have recovered from transplanting; then the balcony glass should be opened appropriately to lower the temperature, but cold wind must be prevented from blowing directly on the seedlings. Watering should be done at midday, and in general water should be controlled to toughen the seedlings; after watering, take care to ventilate and loosen the soil. About 70 days after sowing, the plants can be divided and transplanted into pots for final planting.
Put the prepared potting soil into appropriately sized pots. When potting, cover the drainage hole at the bottom with 1-2 pieces of broken tile, add a little coarse sand, then add the potting soil. After positioning the seedling, first add a small amount of soil to steady it, and dibble monopotassium phosphate between the plants, 2 g/kg each time. Fill with potting soil up to 2-3 cm below the pot rim. Then water, cover with plastic film if desired, and close up the balcony to raise the temperature and help the plants recover; after 4-5 days of warming, ventilate to lower the temperature and proceed with routine care.
This species likes an environment with plenty of soft light. If the light at its location is too strong or too weak, the leaves easily turn pale green or yellow-green, lose their vitality and their ornamental value, and may even dry up and die; if exposed to direct sunlight and dry air, the leaves are most prone to scorching, so it should be placed in a well-ventilated spot with ample indirect light, and care should be taken to maintain environmental humidity.
Apply rotten soybean cake water or homemade fermented liquid fertilizer, or a compound fertilizer, about once a month to provide sufficient nutrients and keep the plant growing vigorously. During cultivation, avoid excessive fertilizer and water, especially too much nitrogen fertilizer, lest the branches and leaves grow rampantly but few flowers appear. If fertilizer and water are controlled appropriately, the plant will grow more slowly, not only producing more flowers but also keeping a compact and graceful shape.
The heartleaf ice plant has a high water requirement during its vigorous growth period from March to September, so it needs frequent watering and misting to increase humidity. In summer, water once every 1-2 days, following the rule of "do not water until dry, and when you water, water thoroughly". After autumn, gradually reduce watering to improve the plant's cold resistance. After October, reduce watering; especially from December to the following January, let the plant wilt slightly and then water thoroughly, which helps flower bud formation and earlier blooming in spring.
Repot once every spring. When repotting, shorten overly long roots and cut away rotten roots; remove pest-damaged and weak vines, cut the stems and vines back to 2-3 nodes, and pick off dead leaves, so as to restore the plant's vigor and maintain a perfect shape. After 2-3 years, new plants can be propagated to renew the stock. For seedlings grown from seed or from cuttings, or plants that have just been repotted in spring, pinch out the growing tips when the new vines reach 6-8 cm to promote a compact, attractive shape and uniform flowering.