rosinweed sunflower

Water rosinweed sunflowers when the top 2 to 3 inches of soil are dry to touch. During the summer months, these plants can need an inch of water per week, either all at once or given in multiple, smaller waterings. During the winter, they will require far less water, about once every 2 weeks. If the temperature is particularly warm and plants are under additional stress, extra water will need to be added.

Rosinweed sunflowers need full sun to thrive, meaning 6-8 hours per day of direct sunlight throughout the entire growing season. Since rosinweed sunflowers are native to the Great Plains of the United States, they are best suited to times of the year when the biggest amounts of direct sunlight are available. Early spring and late summer through autumn are generally the most optimal times of year for rosinweed sunflowers' sun exposure needs. In areas where the climate is milder, rosinweed sunflowers can be planted in late winter and will be able to tolerate some partial shade provided during the hottest parts of the day due to their hardy nature.

When it comes to pruning your rosinweed sunflower (Helianthus silphioides), it is best to wait until after the blooms have faded and the leaves have yellowed, usually sometime during the fall. At this point, the plant will be ready for pruning. You should prune any dead or damaged stems, as well as any that have gotten too tall or have become leggy. Make sure to cut the stems down to just above the existing buds so that new growth will come out from these points. You can also prune out any old or spindly stems that are affecting the overall form of the plant. Prune only as much as necessary for overall plant health, as cutting too much can damage the plant’s root system.