Plants appear simple on the surface. They sit quietly in soil, growing slowly while responding to light and water. Yet, there lies a complex biological system that has evolved for millions of years. Understanding this science is the key to keeping plants healthy in homes, landscapes, restaurants, hotels, and urban environments.
The role of sunlight
Sunlight is the primary driver of plant growth. However, not all plants require the same intensity of light.
Plants such as Bougainvillea, Hibiscus, and Plumeria (Champa) require strong sunlight and typically perform best with at least 5-6 hours of direct sun daily. These species thrive in warm tropical climates across India including Maharashtra, Karnataka, Tamil Nadu, and Telangana.
On the other hand, foliage plants such as Monstera deliciosa, Epipremnum aureum (Money Plant), and Aglaonemacan tolerate lower light conditions. These plants evolved under forest canopies where sunlight is filtered through tree leaves. As a result, they are widely used in indoor landscapes.
Regional climate plays an important role in sunlight management. In north India, winter sunlight becomes weaker and shorter in duration, meaning indoor plants may require brighter window placements. In southern coastal regions such as Kerala and Goa, sunlight remains relatively strong throughout the year, allowing a wider variety of plants to grow outdoors.
Water: Finding the right balance
Water is essential for transporting nutrients and maintaining plant structure. However, the relationship between plants and water is often misunderstood. Contrary to common belief, many plants die not from lack of water but from overwatering. When soil remains constantly saturated, air pockets disappear and roots are deprived of oxygen. This leads to root rot and eventual plant decline.
Plants such as Snake Plant, Aloe vera, and Jade Plant evolved in dry environments and therefore, prefer soil that dries out between watering cycles. These plants perform well in dry urban climates such as Delhi, Jaipur, and Hyderabad.
In contrast, tropical species such as Peace Lily, Ferns, and Calathea prefer consistently moist soil and higher humidity. These plants thrive in humid regions such as coastal Karnataka, Kerala, and parts of northeast India.
Nutrients: Plant nutrition
The primary nutrients essential for plant development are Nitrogen, Phosphorus (P), and Potassium (K). Nitrogen supports leaf growth and vibrant green colour. Phosphorus promotes strong root development and flowering. Potassium strengthens plant tissues and improves resistance to environmental stress.
Flowering plants such as Roses, Marigolds, and Petunias benefit from regular feeding during their flowering seasons. In most parts of India, this period falls between October and March, when temperatures remain moderate.
Organic fertilisers such as compost or vermicompost provide a balanced nutrient supply while improving soil health. In landscapes, these materials mimic natural ecosystems where decaying organic matter continually replenishes nutrients in the soil.
Soil: The hidden ecosystem
Healthy soil is not just a physical support system for plants — it is a living ecosystem. Beneath the surface lies a complex network of microbes, fungi, insects, and organic matter working together to recycle nutrients.
Plants such as Canna indica, Heliconia, and Alpinia thrive in nutrient-rich soils that contain high organic matter. These plants are commonly used in resort landscapes across tropical regions like Goa and Kerala.
In contrast, succulents such as Agave americana and Adenium obesum (Desert Rose) require sandy, well-drained soils that prevent water accumulation around roots.
Improving soil with compost, cocopeat, or sand can dramatically improve plant survival in urban landscapes.
Temperature and adaptation
Most plants grow best within a temperature range of 15-35°C, which fortunately aligns with much of India’s climate. However, seasonal variations influence plant behaviour. In north India, winter temperatures may drop below 10°C, slowing plant growth. Many tropical plants enter a semi-dormant phase during this period.
In contrast, summer temperatures above 40°C in regions such as Rajasthan and central India require heat-tolerant species such as Tecoma stans, Bougainvillea, and Cassia fistula (Amaltas).
Selecting plants adapted to regional climates reduces maintenance and improves landscape resilience.
Plants as living systems
Healthy plants are the result of balanced environmental conditions. Sunlight, water, soil, nutrients, and temperature all interact to create the environment in which plants grow.
When landscapes are designed with this ecological understanding, plants require far less intervention. In cities, where concrete often dominates the landscape, understanding the science behind plants allows us to design spaces where nature and architecture coexist harmoniously.