Species sea holly Guide
grey-blue flowers with green-blue cones and green leaves on purple-green stems

sea holly

Eryngium planum 'Blue Hobbit'

Cycle:

Herbaceous Perennial

Watering:

Minimum

Propagation:

Division,Cutting,Seed Propagation,Layering Propagation

Hardiness Zone:

4 - 8

Flowers:

Purplish blue Flowers

Sun:

Full sun

Growth Rate:

Low

Maintenance:

Low

Drought Tolerant:

Yes

Salt Tolerant:

Yes

Thorny:

Yes

Care Level:

Moderate

watering

Water Sea Holly plants (Eryngium planum 'Blue Hobbit') when the top 2-3 inches of soil surface feels dry. Water deeply and thoroughly until water begins to run from the drainage holes. Do not allow the plants to sit in standing water or overly moist soil. Allow the soil to dry out slightly between waterings, but not to the point of wilting. In hot and dry weather, water Sea Holly plants once every 2-3 days. In cooler, less dry weather, water once per week. Do not water the plants as often during cold, wet months of winter.

sunlight

Sea holly (Eryngium planum 'Blue Hobbit') plants require full sun to partial shade in order to thrive. At least 6 hours of direct sunlight per day should be provided for optimum growth. In cold climates, the plant should be placed in a sheltered area away from frost and strong wind. Sea holly plants like light, airy, well-drained soils. Too much shade can cause weak, floppy foliage. Light shade in the hottest part of the day can help but overall the plant should get more sun than shade.

pruning

Sea holly should be pruned in late spring or early summer. Pruning should be done to maintain the desired shape and size of the plant, taking care to not prune too much or too little. Light pruning can be done throughout the season as needed, but for more significant pruning it is usually best to wait until late spring or early summer after the last frost. When pruning, remove no more than 1-third of the total height of the plant. Doing so will take away any dead or damaged foliage, help open the plant up to better air circulation, and shape the plant.