Key Features
- Yellow leaves
- Reduced growth
- Reduced flowering
Symptoms
Nutrient deficiency symptoms are often difficult to diagnose due to the vagueness of symptoms, and the fact it can look like disease or insect problems. If insect and disease (particularly root rots) have been ruled out, and the plant suffers from stunted growth, yellowing (chlorosis) of the leaves, or between the veins, or an overall purplish-red coloring, nutrient deficiency should be suspected.
Biology
In the Midwest, pH plays a key role in nutrient availability. Heavy clay soils are usually alkaline, which prevents the nutrients from being available to the plant because they are bound to the soil. In the East, poor, thin soils (more common in the older, mountainous soil), sandy soils, or highly acidic soil have nutrients easily leached out.
Management Recommendations
Soil pH and fertility should be determined by a soil test. Contact your local plant and pest diagnostic clinic (provided in the 'i' menu within the app) for more information on how to submit a soil sample. Annuals are heavy feeders and often need repeated applications of fertilizer, particularly for those that are container grown. Most ornamentals grow best in slightly acidic soils (pH 6.5). The pH can be adjusted if your soil is too acidic or alkaline. Most soils throughout the Midwest are fairly fertile, and a soil test will also indicate if any fertilizer is required. Too much fertilizer actually weakens plants, making them grow at the expense of defending themselves from insects or pathogens. Do not fertilize perennials in late summer or early fall. This may prevent plants from going into dormancy before winter, making them susceptible to freeze damage. This may also result in plants growing instead of going dormant.
Effective Pesticides
Pesticides are neither available nor recommended for managing this condition.
