How to Save Dying Geraniums with Rot

Repot or replant the geraniums in clean soil. The bacterium that causes root rot (Xanthomonas pelargonii) can survive for months in soil, so once rot has set in, dispose of the old soil or till it and wait to replant in the next growing season.

Ensure proper drainage. Because bacteria thrive in moist conditions, soil that doesn't drain properly can contribute to root rot. Plants in pots should have drainage holes drilled in the bottom, a layer or gravel, and then a layer of soil on top. Make sure no excess water is collecting or pooling in the decorative pot or plate that your plant is potted in. For geraniums planted in a garden, avoid planting geraniums in areas where there is inadequate sun or you see pools of water after it rains.

Trim away the dead brown parts of the plant, and focus only on the green parts of the plant. However, avoid the long green-stemmed plants, as geraniums that grow extra-long stems are often already infected.

Place the geraniums you are trying to save in separate pots or areas of the garden, as overcrowding can be a contributing factor for root rot.

Cover the topsoil with mulch, as this can be beneficial for the plant's healing process.