Gunnera manicata, commonly known as Giant Rhubarb or Dinosaur Food, is an impressive and dramatic perennial plant that can create a bold statement in the garden. Here is a detailed description and care guide for Gunnera manicata:

Description:
Gunnera manicata is a large herbaceous plant that forms a clump of massive, deeply lobed leaves on thick stalks. The leaves can reach an impressive size, often exceeding 1 meter (3 feet) in diameter. The leaves are textured and resemble the leaves of rhubarb plants, hence the common name "Giant Rhubarb." The plant produces tall flower spikes in summer, bearing small, inconspicuous flowers. The flower spikes can reach heights of 1.8 to 2.4 meters (6 to 8 feet). The plant's overall appearance is robust and tropical, making it a striking focal point in the landscape.

Care Guide:

Light: Gunnera manicata thrives in full to partial sun. However, in areas with hot summers, it benefits from some afternoon shade to prevent leaf scorch.

Soil: Plant Gunnera manicata in rich, moist, and well-draining soil. The plant requires consistently moist soil to thrive, as it is naturally found in wet, boggy environments.

Watering: Gunnera manicata requires ample water to maintain its lush growth. Keep the soil consistently moist, especially during hot and dry periods. Water deeply and provide regular irrigation to ensure the soil remains consistently moist but not waterlogged.

Mulching: Apply a thick layer of organic mulch, such as compost or well-rotted manure, around the base of the plant. Mulching helps to retain soil moisture, suppress weed growth, and provide some insulation to the roots.

Fertilizer: Gunnera manicata benefits from regular feeding to support its vigorous growth. Apply a balanced, slow-release fertilizer in spring, following the package instructions for dosage and frequency. Additionally, you can provide supplemental liquid fertilization during the growing season.

Pruning: Remove old, tattered leaves in spring before new growth emerges. This allows the plant to channel its energy into producing fresh foliage. Additionally, you can trim back spent flower spikes after blooming to maintain a tidy appearance.

Winter Care: In colder regions, Gunnera manicata may require winter protection. After the first frost, cut back the foliage to about 15-30 cm (6-12 inches) above ground level. Surround the crown of the plant with a layer of straw or mulch, and cover it with a layer of burlap or frost cloth to insulate it from freezing temperatures.

Propagation: Gunnera manicata can be propagated through division. Divide the plant in early spring, ensuring each division has a portion of the crown and some healthy roots. Replant the divisions in suitable locations, following the same care guidelines.

Please note that Gunnera manicata is a large and spreading plant that requires ample space to accommodate its size. It is best suited for larger gardens or naturalized areas where it can freely grow and make a dramatic impact. With proper care and suitable growing conditions, Gunnera manicata can become a stunning and eye-catching focal point in your garden.