Cultivation method for improving heat resistance of heuchera micrantha

Abstract

The invention provides a cultivation method for improving heat resistance of heuchera micrantha, and relates to the technical field of gardening flower cultivation. The method comprises the following steps: planting gynostemma pentaphyllum, heuchera micrantha and passionflower in a layered manner, hanging new pteris fern potted plants on a shed frame, and spraying rare earth cerium and a potassium silicate solution. Gynostemma pentaphyllum, heuchera micrantha and passionflower are planted in a layered manner, and new pteris fern potted plants are hung on a shed frame, so that the soil porosity and moisture content of a planting area can be improved, the surface temperature of the planting area in summer is reduced, and the output value per unit area is increased; rare earth cerium and a potassium silicate solution are sprayed on the basis of layered planting, so that the relative conductivity and malondialdehyde content of heuchera micrantha leaves can be reduced, the chlorophyll content can be increased, Pn and Tr of the heuchera micrantha leaves can be increased, the average activity of SOD, POD and CAT of the leaves can be increased, and the survival rate can be increased.

Description

Technical Field

[0001] This invention relates to the field of horticulture, specifically to methods for cultivating flowers, and in particular to a method for improving the heat resistance of Heuchera. Background Technology

[0002] Heuchera spp. is a perennial herb with high ornamental value. Due to its rich leaf color and shade tolerance, it is widely used in landscaping, flower borders, and potted plants. However, native to the cool, humid environments of North America, Heuchera is extremely sensitive to high temperatures (>30°C) and performs poorly in hot tropical, subtropical, and temperate summers. High-temperature stress can cause leaf scorching, discoloration, stunted growth, and even death of the entire plant, severely limiting its commercial applications.

[0003] With global warming and frequent extreme heat waves, the survival rate and ornamental quality of Heuchera (a type of rosebud) have significantly declined in summer, causing huge economic losses to the landscaping industry. For example, in southern China, high summer temperatures (35–40℃) lead to a mortality rate of over 50% for Heuchera, severely restricting its market promotion. Therefore, improving the heat resistance of Heuchera has become a key research direction in horticultural breeding and cultivation techniques.

[0004] Currently, the main methods to improve the heat resistance of Heuchera include variety selection, cultivation regulation, and exogenous substance treatment, but these methods all have significant shortcomings:

[0005] (1) Traditional breeding cycles are long, and it is difficult to balance heat resistance and ornamental value.

[0006] Screening for heat-resistant varieties through hybridization breeding typically takes 5–8 years, and highly heat-resistant varieties often have lighter leaf color or weaker growth, affecting their commercial value. For example, some heat-resistant Heuchera varieties (such as 'Southern Comfort') have leaves that turn green under high temperatures, reducing their ornamental value.

[0007] (2) The cultivation and regulation costs are high, making it difficult to apply on a large scale.

[0008] Shading, sprinkler irrigation, or soil amendments (such as adding water-retaining agents) can alleviate high-temperature damage, but these require continuous human intervention, resulting in high energy and water consumption, which does not meet the needs of sustainable development in modern horticulture.

[0009] (3) The existing treatment of exogenous substances is unstable or poses environmental risks.

[0010] Currently, the most studied exogenous substances include abscisic acid (ABA) and nanomaterials, but these methods have the following problems:

[0011] Concentration dependence: For example, ABA can improve heat resistance at low concentrations (<100μM), but high concentrations inhibit growth.

[0012] Short-term effects: Requires repeated application; cannot maintain heat resistance in the long term.

[0013] Environmental risks: Some nanomaterials (such as nano-cerium oxide) may cause soil pollution.

[0014] Therefore, there is an urgent need to develop an efficient, stable, and environmentally friendly method to improve the heat resistance of heuchera. Summary of the Invention

[0015] The technical solution adopted by this invention to solve its technical problem is:

[0016] A cultivation method for improving the heat resistance of Heuchera includes the following steps:

[0017] Step 1. In early March, Gynostemma pentaphyllum cuttings were planted at the bottom of the Heuchera planting area with a spacing of (35-50)cm × (35-50)cm.

[0018] Each Heuchera planting area has two seedbeds, each 4-5 m long and 1-2 m wide, and 60-80 cm high. Three-year-old Heuchera plants with a crown width of 12-18 cm are placed in the seedbeds for cultivation in early March, with a plant spacing of 18-25 cm × 18-25 cm. Passionflower is cultivated in the greenhouse in early March. Each Heuchera planting area is 4-5 m × 4-5 m.

[0019] Step 2. In mid-to-late April, the passionflowers cultivated in the greenhouse are transplanted to the Heuchera planting area. One passionflower plant is planted in each Heuchera planting area. The vines are 40-60cm long. The spacing between the passionflower trellis supports is (4.5-5.5)m×(4.5-5.5)m, and the height is 2.3-2.7m. The top crossbeam is made of angle steel and a net is hung on the crossbeam with a mesh size of (8-12)cm×(8-12)cm.

[0020] Bird's nest fern potted plants are hung on trellises. The pots are 18-25cm in diameter and 18-25cm in height, with a crown width of 40-60cm and a seedling height of 40-60cm. The hanging spacing is (1.8-2.2)m × (1.8-2.2)m, with the bottom of the pot 1.2-1.5m above the ground.

[0021] Step 3. Spray Heuchera with rare earth cerium solution in summer; the conditions for spraying rare earth cerium solution are: after the average daily temperature exceeds 30℃ for 7 consecutive days, spray on the morning of the next day; first, spray Heuchera leaves evenly with 200-400mg / L potassium silicate solution until the leaf surface is moist but not dripping, and 3-5 hours later, spray with 50-200mg / L rare earth cerium solution.

[0022] Furthermore, in step one, the bottom layer of the heuchera planting area is weeded and prepared, with each 100m² of land being prepared. 2Apply 140-160 kg of sheep manure and 250-350 kg of peat moss as basal soil improvement, spreading them evenly on the surface; deep plow to a depth of 20-40 cm, thoroughly mixing the sheep manure and peat moss with the topsoil; level the soil surface, break up clods, and prepare for seedling transplanting.

[0023] Furthermore, during the cultivation of Heuchera, an integrated water and fertilizer system is adopted, with automatic irrigation nozzles installed on the top-level trellis to ensure even irrigation from the top to the bottom. In winter and spring, irrigation is carried out twice a day, and in summer and autumn, irrigation is carried out three times a day.

[0024] Furthermore, in step two, the heuchera variety is one or a combination of "Golden Zebra", "Berry" and "Eternal Purple".

[0025] Furthermore, in step three, the rare earth cerium solution is a cerium nitrate solution.

[0026] Furthermore, in step three, the rare earth cerium solution is sprayed onto the leaves of Heuchera.

[0027] The function of planting Gynostemma pentaphyllum in the bottom layer in this invention includes:

[0028] (1) Improve soil structure: Gynostemma pentaphyllum, as a bottom cover plant, when combined with sheep manure and peat soil and deeply tilled to a depth of 30cm, can increase soil porosity and improve water retention capacity. (2) Reduce surface temperature: The creeping Gynostemma pentaphyllum forms a dense ground cover layer, reducing direct sunlight on the soil, thereby reducing the surface temperature of the planting area in summer and indirectly alleviating heat stress on Heuchera. (3) Water regulation: Through stratified planting and integrated water and fertilizer irrigation, Gynostemma pentaphyllum can help maintain soil moisture and avoid excessive water loss due to high temperature and drought.

[0029] The benefits of planting passionflower at the top layer in this invention include: (1) Physical shading and cooling: The passionflower trellis is high, and the vines cover the trellis to form a shading layer, blocking direct sunlight and reducing the temperature of the leaves of the middle layer of Heuchera. (2) Microclimate regulation: The transpiration of passionflower leaves increases air humidity, alleviating the pressure of high temperature and dryness on the stomata of Heuchera, and creating a shady microclimate suitable for the growth of Heuchera. (3) Economic benefits and space utilization: As an economic crop, passionflower has the characteristic of climbing growth. By making full use of vertical space and using a layered planting mode (bottom layer Gynostemma pentaphyllum / middle layer Heuchera / top layer Bird's Nest Fern + Passionflower), the yield per unit area is increased.

[0030] The functions of the suspended bird's nest fern bonsai of this invention include: suspending the bird's nest fern bonsai on a pergola creates a moderately spaced and evenly covered "sunshade" surface, which, combined with the upper layer of passionflower and the lower layer of gynostemma pentaphyllum and heuchera, forms a highly efficient composite ecosystem. It not only directly filters strong light but also significantly increases humidity through the collective transpiration of the plant community. Furthermore, it has a synergistic effect with the application of rare earth cerium, working together to reduce the membrane lipid peroxidation level of heuchera cells and comprehensively improve their heat resistance.

[0031] The effects of spraying rare earth cerium in this invention include: (1) alleviating membrane system damage: reducing the relative conductivity and malondialdehyde (MDA) content of leaves, indicating that rare earth cerium can reduce cell membrane lipid peroxidation caused by high temperature and protect cell membrane integrity. (2) enhancing photosynthetic capacity: increasing chlorophyll content and promoting light energy capture; at the same time, increasing net photosynthetic rate (Pn) and transpiration rate (Tr), improving photosynthetic efficiency under high temperature. (3) activating the antioxidant enzyme system: increasing the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), enhancing the ability of heuchera to scavenge reactive oxygen species, and alleviating high temperature oxidative stress.

[0032] This invention utilizes potassium silicate as a spray to strengthen cell walls, reduce mechanical damage caused by high temperatures, form silicified cells, and increase the mechanical strength of plant cell walls, acting as a natural "mechanical or physical barrier." It effectively blocks water or water vapor penetration, maintains the stability of cell membrane structure and function, reduces plant wilting, lowers transpiration, and maintains the stability of cell membrane structure and function, thereby reducing leaf surface water consumption and lowering the respiration rate. Potassium silicate is strongly alkaline and can easily burn leaves when used alone. Rare earth ions can bind to phospholipids in cell membranes, regulate calcium metabolism, and replace calcium... 2+ Participating in Ca 2+ Many physiological processes are involved, therefore, rare earth ions can maintain cell membrane permeability and stability, improve the protective function of cell membranes, and enhance the crop's resistance to adverse environments. Rare earth cerium can promote the stability of cell walls and membrane structures, enhance the plant cells' ability to protect themselves from the external environment, and also increase the activity of antioxidant enzymes, reducing the degree of oxidative damage, thereby slowing down the occurrence of cellular oxidative stress. By inducing stress information transmission and regulating the expression of stress-resistance genes, it guides plants to make more effective physiological responses under adverse conditions. Rare earth cerium treatment mitigates the damage to cell membranes caused by high-temperature stress; it can promote the accumulation of osmotic substances, stabilize osmotic regulation balance, and promote the photosynthetic rate under high-temperature stress. Since potassium silicate has already reduced leaf surface temperature and water loss through physical means, otherwise the plant would have already suffered severe water loss and cell damage due to high temperature, and the effect of cerium would be greatly reduced. The simultaneous use of both forms a complementary and synergistic mechanism of "physical defense + biochemical reaction".

[0033] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0034] Currently, no research has been reported on how rare earth elements can improve the heat resistance of Heuchera. This invention proposes treating Heuchera with cerium nitrate to significantly improve its heat resistance by regulating the antioxidant system, photosynthesis, and heat shock protein expression. The core advantages of this invention include: high efficiency: compared with traditional methods, rare earth treatment under stratified planting can increase the survival rate of the tested Heuchera varieties at 30℃ by 30%-50%; low cost: cerium is a highly abundant rare earth element, and the raw material is inexpensive, making it suitable for large-scale application; environmental friendliness: it avoids the use of high-concentration chemical hormones or genetic engineering technology, aligning with the trend of green agriculture.

[0035] The cultivation method of this invention constructs a microenvironment regulation system through layered planting (Gynostemma pentaphyllum-Heuchera-Bird's Nest Fern-Passionflower), combined with the physiological regulatory effects of rare earth cerium and potassium silicate solutions, synergistically improving the heat resistance, photosynthetic efficiency, and antioxidant capacity of Heuchera, forming a "physiological" heat resistance defense system to achieve stable and high-quality yields during high-temperature seasons. The widespread application of this invention can significantly expand the planting range of Heuchera in high-temperature regions. Detailed Implementation

[0036] Example 1

[0037] 1. Experimental design of the nursery (Xiamen): The nursery area is 100m². 2 The nursery, measuring 10m in length and width, was divided into four 4.6m x 4.6m experimental plots with two 0.8m wide paths running longitudinally and laterally. Weeding and soil preparation were carried out, including applying 150kg of sheep manure and 300kg of peat moss, deep tilling to a depth of 30cm, and leveling the soil. Weeds were removed to ensure a clean surface. 150kg of well-rotted sheep manure and 300kg of peat moss were applied per 100m² as basal soil amendment, evenly spread on the surface. The soil was deep tilled to a depth of 30cm to thoroughly mix the sheep manure and peat moss with the topsoil. The surface was leveled, and clods were broken up in preparation for seedling transplanting. An integrated water and fertilizer system was used, with 30m diameter sprinklers installed on the top trellis for automatic irrigation, spaced 10m apart to ensure even irrigation from top to bottom. Irrigation was carried out twice a day in winter and spring, and three times a day in summer and autumn. The fertilizer used for spraying is Boshengyuan's "Mancui" Smart Farm water-soluble fertilizer (micronutrient type), with the concentration recommended on the packaging.

[0038] 2. In early March, Gynostemma pentaphyllum was planted at a spacing of 40cm×40cm in the bottom layer of the experimental area, with a planting depth of about 5cm and leaves facing the same direction. After planting, the cuttings were thoroughly watered.

[0039] Each experimental plot has two 4.6m×1.6m seedbeds, 70cm high. Three-year-old potted Heuchera 'Golden Zebra', 'Berry' and 'Eternal Purple' with a crown width of about 15cm are used as research subjects. They are placed in the seedbeds for cultivation in early March, with a plant spacing of 20cm×20cm.

[0040] Passionflowers were cultivated in greenhouses in early March and transplanted to the experimental area in mid-to-late April. One passionflower plant was planted in each experimental plot. The vines were 50cm long. The passionflower trellis supports were spaced 5m×5m apart and 2.5m high. The top beams were made of angle steel and netting with 10cm×10cm mesh was hung on them.

[0041] Bird's nest ferns are hung in pots on a pergola. The pots are 20cm in diameter and 20cm high, with a crown width of about 50cm and the seedlings about 50cm tall. The pots are hung 2m x 2m apart, centered on the fern plant, providing shade while ensuring some light. The bottom of the pots is 1.4m above the ground, suitable for harvesting the fern leaves. This creates a moderately spaced, evenly covered "sunshade" surface, which, combined with passionflower on top and gynostemma pentaphyllum and heuchera on the bottom, forms a highly efficient composite ecosystem.

[0042] 3. The conditions for spraying the rare earth cerium solution are as follows: spraying should be done on the morning of the day after seven consecutive days of average daily temperature exceeding 30°C in summer (i.e., spraying should be done on the morning of the following day after seven consecutive days of average daily temperature exceeding 30°C in summer). First, spray the leaves of Heuchera evenly with a 300 mg / L potassium silicate solution until the leaf surface is moist but not dripping. Four hours later, spray the rare earth cerium solution. The rare earth cerium solution is a cerium nitrate solution. The concentration of the rare earth cerium solution sprayed on the leaves of Heuchera is 100 mg / L.

[0043] Soil-related indicators were measured after 3 months of high temperature; leaf physiological indicators were measured 5 days after spraying with rare earth cerium solution. Measurement methods:

[0044] The following measurements were performed using a Yaxin-1105 portable photosynthetic fluorescence spectrometer: MDA content determination (thiobarbituric acid method), conductivity determination (conductivity meter method), soluble protein content determination (Coomassie brilliant blue method), soluble sugar content determination (anthrone method), chlorophyll content determination (spectrophotometry), catalase (CAT) activity determination (UV absorption method), peroxidase (POD) activity determination (guaiacol method), superoxide dismutase (SOD) activity determination (nitroblue tetrazolium (NBT) method), and average net photosynthetic rate (Pn) and average transpiration rate (Tr) of leaves.

[0045] The control group received no treatment. Two 4.6m × 1.6m seedbeds, 70cm high, were also installed in the control plots. Three-year-old potted Heuchera 'Golden Zebra', 'Berry', and 'Eternal Purple' plants with a crown width of approximately 15cm were used as the research subjects. These were placed in the seedbeds in early March, with a plant spacing of 20cm × 20cm. However, the control group did not have stratified planting of Gynostemma pentaphyllum, bird's nest fern, or passionflower, nor were they sprayed with rare earth cerium solution or potassium silicate solution. Other nursery treatments, water and fertilizer treatments, and other management methods were the same as the experimental group.

[0046] Experimental results:

[0047] Layered planting of Gynostemma pentaphyllum, Heuchera, bird's nest fern, and passionflower, along with spraying with rare earth cerium solution, increased soil porosity by 2-4% and average soil moisture content by 1-2% in the experimental area, while reducing surface temperature by 4-6℃ in summer.

[0048] Heuchera "Golden Zebra": See Table 1. The average malondialdehyde (MDA) content in the leaves decreased by approximately 5.6%, the average relative conductivity decreased by approximately 20.8%, the average soluble protein content increased by approximately 18.6%, and the average soluble sugar content increased by approximately 26.5%. The average chlorophyll a content in the leaves increased by approximately 7.8%, and the average chlorophyll b content increased by approximately 8.2%. The average net photosynthetic rate (Pn) of the leaves increased by approximately 9.5%, and the average transpiration rate (Tr) increased by approximately 16.2%. The average catalase (CAT) activity in the leaves increased by approximately 10.2%, the average peroxidase (POD) activity increased by approximately 35.5%, and the average superoxide dismutase (SOD) activity increased by approximately 23.9%.

[0049] Table 1 Results of the "Golden Zebra" Experiment

[0050]

[0051] Heuchera "Berry": See Table 2. The average malondialdehyde (MDA) content in the leaves decreased by approximately 7.2%, the average relative conductivity decreased by approximately 21.2%, the average soluble protein content increased by approximately 17.5%, and the average soluble sugar content increased by approximately 28.6%. The average chlorophyll a content in the leaves increased by approximately 8.9%, and the average chlorophyll b content increased by approximately 7.6%. The average net photosynthetic rate (Pn) of the leaves increased by approximately 20.3%, and the average transpiration rate (Tr) increased by approximately 36.6%. The average catalase (CAT) activity in the leaves increased by approximately 15.6%, the average peroxidase (POD) activity increased by approximately 20.5%, and the average superoxide dismutase (SOD) activity increased by approximately 21.6%.

[0052] Table 2 Results of the "Berry" Experiment

[0053]

[0054] Heuchera 'Eternal Purple': See Table 3. The average malondialdehyde (MDA) content in leaves decreased by 6.9%, the average relative conductivity decreased by 23.9%, the average soluble protein content increased by 19.6%, and the average soluble sugar content increased by 27.1%. The average chlorophyll a content in Heuchera leaves increased by 8.8%, and the average chlorophyll b content increased by 7.1%. The average net photosynthetic rate (Pn) of leaves increased by 38.1%, and the average transpiration rate (Tr) increased by 25.2%. The average catalase (CAT) activity in leaves increased by 19.8%, the average peroxidase (POD) activity increased by 28.5%, and the average superoxide dismutase (SOD) activity increased by 25.6%.

[0055] Table 3 Results of the "Eternal Violet" Experiment

[0056]

[0057] After summer, the survival rates were measured. The survival rate of "Golden Zebra" was about 83%, which was about 31 percentage points higher than the control group (the survival rate of the Golden Zebra control group was about 52%). The survival rate of "Berry" was about 75%, which was about 33 percentage points higher than the control group (the survival rate of the Berry control group was about 42%). The survival rate of "Eternal Purple" was about 69%, which was about 41 percentage points higher than the control group (the survival rate of the Eternal Purple control group was about 28%).

[0058] In summary, this invention, through a "physical-physiological" dual-effect synergistic mechanism, organically combines the construction of a complex ecosystem with the regulation of exogenous substances, forming a highly efficient, stable, and environmentally friendly comprehensive cultivation scheme for improving the heat resistance of Heuchera. Its advantages are mainly reflected in the synergistic effects at the following three levels:

[0059] I. Synergy of Spatial Structure and Microclimate Regulation: This invention establishes a three-dimensional, layered planting model of "Gynostemma pentaphyllum (bottom layer) - Heuchera (middle layer) - Bird's Nest Fern + Passionflower (top layer)". This model is not a simple stacking of plants, but rather the construction of a highly efficient composite ecosystem that achieves synergy between physical shading and microclimate regulation. The upper-layer passionflower pergola and the hanging bird's nest ferns together form an adjustable "sunshade," effectively filtering strong light and reducing the leaf surface temperature of the middle-layer Heuchera. At the same time, the transpiration of each layer of plants produces a synergistic effect, significantly increasing the air humidity of the planting area and jointly creating a cool and humid microclimate suitable for Heuchera growth. The lower-layer Gynostemma pentaphyllum reduces water evaporation and lowers soil temperature by covering the ground surface, and, in conjunction with soil improvement measures, further optimizes the rhizosphere environment. This multi-layered spatial layout achieves comprehensive environmental regulation from above ground to below ground, laying a solid physical foundation for Heuchera to resist high-temperature stress.

[0060] II. Sequential Synergy of Exogenous Substances' "Physical Defense" and "Biochemical Activation": At the physiological regulation level, this invention designs a sequential spraying strategy of potassium silicate and rare earth cerium (cerium nitrate). The two complement each other, forming a temporal synergy. The first sprayed potassium silicate solution forms a natural silicified protective layer on the leaf surface, acting as a "physical barrier," strengthening cell walls and reducing water loss, thus preferentially stabilizing cell structure at high temperatures and creating a good foundation for subsequent treatments. Several hours later, the sprayed rare earth cerium solution focuses on "biochemical activation": it can effectively penetrate into the plant, enhancing the ability of Heuchera to scavenge reactive oxygen species and reducing membrane lipid peroxidation damage by increasing the activity of key antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). (This manifests as a significant decrease in malondialdehyde (MDA) content and relative conductivity). Simultaneously, rare earth cerium also promotes the synthesis of photosynthetic pigments and improves gas exchange parameters (increasing net photosynthetic rate Pn and transpiration rate Tr), ensuring energy supply at high temperatures. This strategy of first establishing physical defenses and then activating biological and chemical protection achieves a synergistic protection effect that progresses from the outside in and layer by layer.

[0061] III. Synergistic Effects of Ecological and Economic Benefits: Compared with traditional single shading or chemical treatments, this method has significant comprehensive advantages. In terms of ecological benefits, it avoids the use of high-concentration chemical hormones or materials with potential environmental risks, meeting the requirements of green agriculture; the stratified planting model increases biodiversity and output value per unit area (such as the economic benefits of passion fruit). In terms of application benefits, the method has stable and lasting effects, reducing the energy consumption and costs of continuous artificial intervention through the ecosystem's self-regulation; the rare earth element cerium used is widely available and inexpensive, facilitating large-scale promotion and application. Ultimately, this method can significantly improve the survival rate of Heuchera under continuous high temperatures, effectively expanding its planting range in hot regions such as southern my country, and has significant industrial application value.

[0062] The above description is merely a preferred embodiment of the present invention, and therefore should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent and the contents of the specification should still fall within the scope of the present invention.

Claims

1. A cultivation method for improving the heat resistance of Heuchera, characterized in that, Includes the following steps: Step 1. In early March, Gynostemma pentaphyllum cuttings were planted at the bottom of the Heuchera planting area with a spacing of (35-50)cm × (35-50)cm. Each Heuchera planting area has two seedbeds, each 4-5 m long and 1-2 m wide, and 60-80 cm high. Three-year-old Heuchera plants with a crown width of 12-18 cm are placed in the seedbeds for cultivation in early March, with a plant spacing of 18-25 cm × 18-25 cm. Passionflower is cultivated in the greenhouse in early March. Each Heuchera planting area is 4-5 m × 4-5 m. Step 2. In mid-to-late April, the passionflowers cultivated in the greenhouse are transplanted to the Heuchera planting area. One passionflower plant is planted in each Heuchera planting area. The vines are 40-60cm long. The spacing between the passionflower trellis supports is (4.5-5.5)m×(4.5-5.5)m, and the height is 2.3-2.7m. The top crossbeam is made of angle steel and a net is hung on the crossbeam with a mesh size of (8-12)cm×(8-12)cm. Bird's nest fern pots are hung on the trellis. The pot diameter is 18-25cm, the pot height is 18-25cm, the crown width is 40-60cm, and the seedling height is 40-60cm. The hanging spacing is (1.8-2.2)m × (1.8-2.2)m, calculated from the center of the bird's nest fern plant. The bottom of the pot is 1.2-1.5m from the ground. Step 3. Spray Heuchera with rare earth cerium solution in summer; the conditions for spraying rare earth cerium solution are: after the average daily temperature exceeds 30℃ for 7 consecutive days, spray on the morning of the next day; first, spray Heuchera leaves evenly with 200-400mg / L potassium silicate solution until the leaf surface is moist but not dripping, and 3-5 hours later, spray with 50-200mg / L rare earth cerium solution.

2. The cultivation method for improving the heat resistance of Heuchera according to claim 1, characterized in that: In step one, the bottom layer of the heuchera planting area is weeded and prepared, with each 100m² of land being prepared. 2 Apply 140-160 kg of sheep manure and 250-350 kg of peat moss as basal soil improvement, spreading them evenly on the surface; deep plow to a depth of 20-40 cm, thoroughly mixing the sheep manure and peat moss with the topsoil; level the soil surface, break up clods, and prepare for seedling transplanting.

3. The cultivation method for improving the heat resistance of Heuchera according to claim 1, characterized in that: During the cultivation of Heuchera, an integrated water and fertilizer system is adopted. Automatic irrigation nozzles are installed on the top shelf to ensure that the top and bottom layers can be irrigated evenly. In winter and spring, irrigation is carried out twice a day, and in summer and autumn, irrigation is carried out three times a day.

4. The cultivation method for improving the heat resistance of Heuchera according to claim 1, characterized in that: In step two, the heuchera varieties are one or more combinations of "Golden Zebra", "Berry" and "Eternal Purple".

5. A cultivation method for improving the heat resistance of Heuchera according to claim 1, characterized in that: In step three, the rare earth cerium solution is a cerium nitrate solution.

6. The cultivation method for improving the heat resistance of Heuchera according to claim 1, characterized in that: In step three, the rare earth cerium solution is sprayed onto the leaves of Heuchera.

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