Dragon Tree: Perfect Plant for Beginners

Powdery mildew is a common fungal disease caused by various fungi species including Erysiphe, Podosphaera, Oïdium, and Leveillula. It affects over 10,000 plant species worldwide. The disease thrives in warm, dry climates with high humidity and appears as a distinctive white powdery coating on plant surfaces.

Root rot is a serious fungal disease that affects the root system of plants, causing them to decay and die. It is primarily caused by overwatering, poor drainage, or soil-borne fungi such as Pythium, Phytophthora, Rhizoctonia, and Fusarium. The disease thrives in waterlogged conditions where roots are deprived of oxygen, making them susceptible to fungal infection.

Gray mold, caused by the fungus Botrytis cinerea, is one of the most common fungal diseases in plants. It affects over 200 plant species, including ornamentals, vegetables, fruits, and houseplants. The disease thrives in cool, humid conditions with poor air circulation, causing grayish spots and soft rot on infected tissues.

Fusarium wilt is a serious fungal disease caused by the soil-borne fungus Fusarium oxysporum. The fungus invades roots and blocks the water-conducting vessels (xylem) of the plant, causing progressive wilting and eventual death. Host-specific forms of the pathogen exist that attack different plant species.

Leaf spot is a common fungal disease caused by various pathogens including Alternaria, Ascochyta, Colletotrichum, Septoria, and Venturia. It primarily affects leaves, causing discolored spots that can lead to premature leaf drop if left untreated.

Southern blight is a devastating soilborne fungal disease caused by Athelia rolfsii (formerly Sclerotium rolfsii), affecting over 500 plant species including vegetables, ornamentals, and fruit crops. The fungus survives in soil through resting structures called sclerotia that resemble mustard seeds and can remain viable for years.

Scale insects are small sap-sucking pests that appear as brown, shell-like bumps on plant stems and leaves. There are over 25 species, divided into armored (hard) and unarmored (soft) scales. They feed by piercing plant tissue and extracting sap, which weakens the plant and can lead to yellowing, stunted growth, and even death if left untreated. They also excrete honeydew, which attracts ants and promotes sooty mold growth.

Spider mites are tiny arachnids (less than 1/20 inch long) related to spiders and ticks that feed on plant sap. They thrive in hot, dry conditions and can cause significant damage to ornamental and vegetable plants. During severe infestations, crop losses can reach 14% or higher as these pests disrupt vital plant processes including photosynthesis, carbon dioxide absorption, and transpiration.

Whiteflies are small, soft-bodied, winged insects closely related to aphids and mealybugs. They are moth-like in appearance, about 1/16 inch long, triangular in shape, and gray-white in color. These sap-sucking pests feed on plant tissue, causing yellowing, stunted growth, and wilting. They also excrete honeydew, which attracts ants and promotes sooty mold growth. Whiteflies can transmit serious plant viruses.

Mealybugs are small, soft-bodied insects covered with a white, waxy, cottony material. They are common pests of houseplants and outdoor plants in mild climates. These sap-sucking insects feed on plant tissue, causing damage, stunted growth, and can lead to plant death if left untreated. They produce sticky honeydew which attracts sooty mold.

Overwatering occurs when plants receive too much water, depriving roots of oxygen and causing root rot. This environmental stress is one of the most common causes of houseplant death, as waterlogged soil prevents roots from breathing and functioning properly.

Low light stress, also known as etiolation, occurs when plants do not receive adequate light for proper growth and development. This leads to abnormal growth patterns characterized by elongated stems, pale leaves, and weakened overall structure as the plant attempts to reach toward available light sources.

Underwatering or drought stress is a physiological disorder that occurs when the amount of water a plant loses through transpiration exceeds the amount its roots can absorb from the soil. This leads to cellular dehydration and various visible symptoms that can compromise plant health and productivity.

Low humidity stress occurs when indoor air becomes too dry, causing plants to lose moisture faster than they can absorb it through their roots. This is especially common during winter heating periods, near radiators and heating vents, or in air-conditioned spaces. Tropical plants are particularly susceptible to low humidity damage.

Sunburn or sun scorch is an environmental condition that occurs when plants are exposed to intense, direct sunlight beyond their tolerance level. This causes the breakdown of chlorophyll in the leaves, resulting in bleached, dried, and damaged foliage. The damage can happen rapidly, sometimes within just a few hours of exposure.

Leaf tip necrosis, also known as tip burn, is a non-infectious environmental condition where the tips and edges of leaves turn brown, dry, and crispy. This occurs due to various stress factors affecting the plant's ability to maintain healthy tissue at the leaf extremities.

Aphids are small, soft-bodied, pear-shaped insects (1/16 to 1/8 inch long) that feed by sucking nutrient-rich sap from plants. They reproduce rapidly and can quickly weaken plants, causing distorted growth and transmitting plant viruses. Aphids come in various colors including green, black, red, yellow, brown, and gray. They secrete honeydew, a sticky substance that attracts ants and encourages sooty mold growth.

Thrips are tiny cigar-shaped insects (1/25-inch long) that damage plants by sucking plant juices and scraping at fruits, flowers, and leaves. With over 6,000 species and rapid reproduction (lifecycle as short as 14 days), they can quickly infest plants and transmit viruses like tomato spotted wilt virus.