Heartleaf Arnica

Heartleaf Arnica typically requires moderate watering, with 3-4 inches of water per week being suggested for optimal plant health. Water should be applied evenly, spread out over the course of the week as opposed to 1 large portion. Check the soil before watering to help determine how much water is needed. If the soil is generally moist or damp 1-2 inches of water should be enough. During hotter, drier weather, water may need to be increased. If the leaves are wilting or curling, the plant likely needs more water. Too much water can be just as harmful as too little, so make sure not to overwater.

Heartleaf Arnica needs about 6 hours of direct sunlight per day when grown in the garden. The best time for providing sunlight to the plant is in the morning, from sunrise until mid-morning. During the midday hours, while direct sunlight is still beneficial, too much intense sunlight can be harmful and potentially cause leaf burn, so it's best to provide some shade with a canopy or similar structure at least for a few hours. To ensure ample sunlight, it’s best to plant in an area facing the southeast in the northern hemisphere or the northwest in the southern hemisphere. This plant species is also known to do well in partial shade, but in order to ensure healthy growth, the less shade provided, the better.

Heartleaf Arnica (Arnica cordifolia) can be pruned in the early spring just before new growth begins. Pruning should be done lightly and not all the way down to the ground as this can result in damage to the plant. Generally, it is best to remove any dead, diseased, or weak stems and flower stalks, and shape the plant as desired. Additionally, any crossing or bushy stems should be pruned to promote air circulation and sunlight penetration. Since Arnica heartleaf has a spreading habit, excess lateral branches can be trimmed to reduce sprawling. Overall, it is important not to remove more than 1/3 of the plant when pruning as excessive pruning can negatively impact the health of the plant.