The difficulty of growing certain plants stems from an inability to meet their rigid needs, which fall into three main categories: requiring a unique environment, demanding continuous, highly specialized care, or possessing an intrinsic fragility during establishment. Plants become “hard to grow” when success depends on recreating conditions far removed from a standard home or garden setting. These species require extraordinary effort and precise control over their surroundings and maintenance routines. Understanding the specific nature of a plant’s difficulty is the first step toward successful cultivation.
Environmental Extremists
Some plants are difficult because their survival depends on replicating the narrow environmental parameters of their native habitat. These species are inflexible, often failing when conditions shift even slightly outside a specific range. The challenge lies in maintaining a static, specialized setting, such as a precise temperature or soil chemistry.
High-altitude carnivorous plants like certain Nepenthes pitcher species are a prime example, requiring a significant and consistent temperature drop every night. These highland varieties thrive with daytime temperatures around 75–83°F but need nighttime temperatures to consistently fall to 55–60°F, a differential that is difficult to provide without a climate-controlled enclosure or greenhouse. They also demand high humidity, often exceeding 75% during the day, which standard indoor environments cannot sustain.
Other species depend on an unchangeable soil chemistry, such as calcifuges, or “lime-fleeing” plants. Rhododendrons, blueberries, and azaleas require highly acidic soil (pH 4.5 to 5.5) to effectively access essential micronutrients like iron and zinc. If the soil pH rises above this narrow range, these nutrients become chemically “locked up,” resulting in chlorosis and stunted growth. The inability to easily maintain these static conditions in a typical garden bed makes them challenging.
Specialized Maintenance Demands
A different set of plants is considered difficult because they require continuous, high-skill human intervention rather than just a specialized environment. The difficulty is dynamic, based on the gardener’s knowledge, precision, and relentless attention to detail. The maintenance challenge lies in the complex skill necessary for shaping and training the plant.
Bonsai trees require constant, highly technical intervention, including structural and maintenance pruning to control their size and shape. The technique of wiring involves wrapping branches with specific gauges of aluminum or copper wire, often half the diameter of the branch, to physically bend them into a desired form. This wire must be monitored and removed at the precise moment the branch sets to prevent the wire from cutting into the bark and scarring the tree as it thickens.
High-maintenance species, such as show roses or specific ornamental varieties, demand a complex, phased feeding schedule. Achieving perfect blooms requires adjusting the nutrient ratio throughout the growing season, supplying high-nitrogen formulas during vegetative growth and switching to phosphorus and potassium-heavy feeds for flowering. This precise nutrient management is necessary to maximize bloom quality.
Plants like the tropical Calathea are difficult due to their extreme susceptibility to common pests, demanding continuous vigilance. These foliage plants are highly prone to infestations from pests like spider mites, which thrive in the dry conditions common in most homes. Growers must constantly balance the plant’s need for high humidity (50–70% is preferred) with the need for good air circulation to prevent fungal diseases like powdery mildew, making routine care an ongoing, delicate balancing act.
The Challenge of Propagation and Establishment
The final category includes plants that are highly vulnerable during their initial stages of life or take an inordinate amount of time to reach maturity. This makes the establishment phase a multi-year risk, requiring patience and specialized techniques to overcome developmental barriers. The most common challenge is the requirement for stratification, a process that mimics the cold, moist conditions of winter.
Many perennial seeds, such as those from lavender or some native wildflowers, possess a deep dormancy and will not germinate unless they are subjected to a period of cold-moist stratification for several weeks or months. This is a natural mechanism that prevents the seed from sprouting too early in the season, and the grower must artificially replicate this chill in a refrigerator to trigger a successful germination. Failure to do this results in low, erratic, or non-existent sprouting rates.
Another key difficulty is the fragility of the root system, which makes transplanting a high-risk activity. Plants with a single, long taproot, such as poppies or certain root vegetables, are notoriously difficult to move once established. Any disturbance or breakage to the main taproot during transplanting can lead to severe shock, stunting, or complete plant failure, necessitating that they be sown directly into their final growing location.
Slow-growing species, like some cacti, certain conifers, or the Sansevieria (snake plant), test the gardener’s patience. These plants can take years to show significant growth, with some indoor varieties only producing a few leaves annually. This prolonged establishment phase means that any minor set-back can cost the grower an entire year of progress, making the long-term commitment a significant factor in their difficulty.