As succulents have gained popularity as household plants, people's curiosity about their appearance has also increased. One phenomenon that succulent enthusiasts particularly admire is the "sugar heart." This feature occurs when the center of the succulent rosette develops a highly saturated pink or red hue due to environmental stress, resembling a tempting piece of crystal candy.
It’s important to note that this striking coloration is not a genetic mutation but a normal growth response. Just as succulents can change color in response to varying temperatures and sunlight exposure, the "sugar heart" results from concentrated anthocyanins, carotenoids, and an increased level of sugars in the plant's vacuoles. If you are interested in cultivating a "sugar heart" in your succulents, this blog will guide you through the secrets of achieving this beautiful phenomenon.
Is the “sugar heart” an ordinary phenomenon?
Although "sugar hearts" is a normal state of succulents, in addition to the extreme maintenance conditions, whether the succulents themselves have the characteristic of "producing sugar hearts" is also very important. Not all succulent varieties possess the capability to produce "sugar hearts."
Here are several classic varieties that are easy to produce sugar hearts:
1. Echeveria 'Ice Green': This popular Korean hybrid has short, round, and compact leaves. With proper care, its center may develop a translucent orange-pink hue.
2. Echeveria Monroe: This variety features leaves coated with a thick layer of white powder. Under strong light, the center turns orange-red, creating a striking contrast between the sugar heart and the pink edges.
3. Echeveria Snow Angel: A hybrid of Echeveria Laui and Echeveria Monroe, this variety often displays sugar hearts accompanied by ice cracks.
4. Echeveria 'Sugar Heart': A specifically bred Korean variety, it naturally accumulates sugar in the leaf hearts.
5. Echeveria 'Rococo': Known for its distinctly wrinkled leaves, this variety typically showcases sugar hearts in gradient shades of pink and purple.
Golden rules for choosing sugar-heart varieties:
1. Prefer Korean hybrid varieties: Korean succulent growers have bred varieties with obvious sugar-heart tendencies through multiple generations of screening.
2. Observe the state of the mother plant: When purchasing, choose plants with slight sugar-heart performance in the center, which have more significant genetic advantages.
3. Beware of the "drug brocade" trap: Some merchants make fake sugar hearts by spraying hormones, and the leaves will show unnatural whitening or abnormal growth, so it is necessary to distinguish the authenticity.
How to Promote "Sugar Heart"?
The "sugar heart" state in succulents requires human intervention in their growth conditions, such as light, temperature, water, and soil. This is particularly important in areas where these four conditions are not optimal. Achieving the "sugar heart" appearance will take more time and effort the more extreme the necessary interventions are. However, if you live in California, you are already at an advantage compared to growers in other regions.
1. Light: The Photonic Catalyst
(1) Spectral Optimization
UV-B Exposure: 2-3 hours of morning/evening direct sunlight triggers anthocyanin synthesis.
LED Spectrum: Use full-spectrum grow lights with 450nm (blue) and 660nm (red) peaks.
Photoperiod: 12-14 hours daily using smart timers for consistency.
(2) Implementation
Outdoor Cultivation: Use 30-50% shade cloth during midday in growing seasons.
Indoor Setup: 36W LED panels at 20-30cm height, maintaining 8,000-10,000 lux.
Rotation: Adjust pot orientation weekly to prevent asymmetric growth.
2. Temperature Difference: A Natural Concentrator of Sugar
(1) Diurnal Temperature Flux
Day: 25-30°C/77-86℉ for photosynthesis-driven sugar production.
Night: 10-15°C/50-59℃ to minimize respiratory sugar loss.
(2) Seasonal Protocols
Spring/Fall: Maximize natural outdoor temperature swings.
Winter: Maintain 5°C/41℉ night drops in insulated greenhouses.
Summer: Use evaporative cooling (fans + humidifiers) for 5-8°C/41-46.4℉ differentials.
3. Water Stress Management
(1) Adaptive Watering
Visual Cues: Water when outer leaves show 30% flexibility loss.
Seasonal Adjustments:
Spring/Fall: 7-10 day intervals
Summer: 15-20 days (water at night)
Winter: 20-30 days (use room-temp water)
(2) Advanced Techniques
Progressive Drought Training: Gradually extend intervals from 10→15 days.
Peripheral Watering: For established sugar hearts, moisten only pot edges.
4. Micronutrient Optimization
(1) Fertilizer Formulations
NPK Ratio: 5-10-10 base with 2% Ca/Mg and chelated Fe/Mn.
DIY Boosters: Banana peel extract (1:1000 dilution) for potassium.
(2) Application Guidelines
Prime Timing: Apply during spring/fall growth spurts.
Absolute Bans: No fertilizing above 32°C/89.6℉ or during dormancy.
5. Potting Soil: Adjust according to the regional climate and humidity
Dry areas: 70% granules plus 30% peat plus 3% rice husk charcoal, which is used to adjust the pH value.
Wet areas: 85% granules plus 15% peat plus 5% volcanic rock, which can effectively prevent soil from caking and hardening.
Rooting period of seedlings: 50% granules plus 50% peat plus 10% vermiculite, which has a certain water retention capacity compared to perlite, which is helpful for seedlings to grow roots.
6. Repotting and Root Pruning
Repotting: Cut off water for 3 days in advance, and tap the pot wall to remove the plant.
Root pruning: Cut off all fibrous roots, keep the main root 1-2 cm, and dry the roots for 48 hours.
Potting: Plant with moist soil (humidity 30%), place in scattered light for 7 days, then give it a thorough drink.
7. Disease prevention and control
(1) Common diseases and pests
a. Heart of the sugar plant burn: Transparent water stains appear on the central leaves. The succulent needs to be moved to a cool place, the damaged tissue needs to be removed, and it needs to be allowed to dry naturally before regrowth. The removed part may grow abnormally.
b. Fungal infection: White floccules appear in the heart of the leaves. You can use a cotton swab dipped in 75% alcohol to wipe and disinfect it locally.
c. Scale insect pests: White insect bodies are attached to the heart of the sugar plant. You can wipe it with alcohol and then spray it with dimethoate solution (1:2000) for 3 times/3 days.
(2) Preventive maintenance
a. Spray mancozeb (1:1000) once per month to prevent fungi.
b. Irrigate with avermectin (1:1500) to prevent root mealybugs, once per quarter.
c. Replace all potting soil and sterilize thoroughly in the spring.
You may wonder: A Full Guide on Molds/Spots on Succulents
8. What's More
Advanced succulent growers like to explore and break through the extreme state of the sugar heart. If you have a mature grow tent and sufficient funds, perhaps the following three tips will be helpful to you.
(1) Photoperiod regulation method
In the autumn and winter seasons, the daily light is extended to 16 hours through artificial light supplementation, and then suddenly reduced to 8 hours after 4 weeks, which can stimulate the concentrated outbreak of the heart of the sugar.
(2) Low-temperature acclimation technology
Progressive low-temperature training for mature plants: starting from 15℃/59℉, reducing 2℃/35.6℉ per week, and maintaining a minimum of 5℃/59℉ for 3 days can induce the color of the heart of the sugar to deepen.
(3) CO₂ enrichment system
Injecting food-grade CO₂ (concentration 800-1200ppm) into the closed maintenance box can increase photosynthetic efficiency by 30%, and the saturation of the heart of the sugar will increase significantly.
Conclusion
The process of promoting the ultimate heart of the sugar is essentially a process of simulating the adverse environment of the native place of succulents. Every time the water control causes the leaves to shrink, and every temperature difference causes the pigment to precipitate, it is an interpretation of the subtle adaptation of life to the environment. It is recommended that enthusiasts set up a maintenance log to record data such as temperature and humidity, light intensity, and plant changes. Through 3-5 growth cycles of observation and adjustment, you will eventually master your method and secrets to grow the succulents.
