Mealybugs on houseplants are difficult to control. Unless the plant is particularly valuable, it’s often best to throw away the infested plant before the insects spread to other houseplants. The standard remedies for houseplant pests…
Spider mites are a common pest of houseplants. Spider mites use piercing-sucking mouthparts to puncture the plant tissue and feed on the liquid within the cells. In light infestations, the foliage appears to be speckled with very tiny…
While not a regular occurrence, it is not unusual for the foliage of fall-planted bulbs like garlic to emerge a bit early during a mid-winter warm-up. While in Iowa garlic normally begins to emerge from the ground in mid-March to early April,…
The brown growths in your ash tree are probably ash flower galls. Galls are abnormal plant growths induced to form by small insects, mites, or other organisms. On ash trees, a tiny mite causes the male flowers to develop into roundish…
The symptoms of salt injury to deciduous trees and shrubs include stunted growth, marginal leaf scorch, early fall coloration, and twig dieback. Accumulation of salt in the soil over several years may result in progressive decline and eventual…
The Emerald Ash Borer (EAB) is an exotic destructive pest that kills all native ash trees (Fraxinus). The loss of ash trees significantly impacts the urban tree canopy. While treatment options are available, some trees cannot be treated…
Yellowing, browning, and dropping of leaves is one of the most vague and difficult issues to deal with because it can be caused by a wide variety of issues. Many of the problems seen in houseplants are not caused by just one factor, they are the…
Honeydew is a sticky, sugar-rich substance produced by insects that suck sap from plant leaves and stems. This excretion often coats lower leaves, tables, and floors and when severe, may promote the growth of black sooty mold.
In the home landscape, rabbits feed on herbaceous plants (annuals, perennials, vegetables, and grasses) during the growing season. Trees and shrubs become food sources in late fall and winter (December through March). Damage to trees…
Winter (December through February) is the best time to prune oak trees in Iowa. Pruning oak trees in winter greatly reduces the risk of an oak wilt infection.
Oak wilt is a fungal disease that is lethal to many oaks. It…
Repeated freezing and thawing of the soil during the winter months can lift up or heave some perennials out of the soil. Heaving exposes the plant’s crown and roots to cold, dry air. Perennials that have been heaved up out of the…
Environmental conditions indoors during the winter months are often rather poor. Low light levels, cold drafts, low relative humidities, and other environmental factors are stressful to plants. The stressful conditions may cause figs…
Brown leaf tips or edges can happen on any indoor plant but are common on some species like spider plant and dracaena. Trimming the brown portions off the leaves with a scissors can improve appearance, but new browning will occur if…
Wilting is the result of roots not being able to provide adequate moisture to the leaves and stems. It can be caused by two completely opposite reasons, either under-watering or over-watering, which can make it difficult to diagnose and…
The whitish or brown molds that grow on the surface of peat pots and other organic materials are unsightly, but will not harm healthy seedlings. However, the presence of molds may indicate excessive moisture levels. Overwatering may lead to…
The small, yellow mushroom is probably Leucocoprinus birnbaumii. The fungus is sometimes referred to as yellow houseplant mushroom, yellow parasol, or flower pot parasol. This species can be found outside in summer, but is…
