sea holly

Sea holly should be watered regularly, usually every 2-3 days in the growing season, but it is important to check the soil first to make sure it doesn't stay too wet. Water deeply, so that it reaches the root system, and stop when it starts to run out of the base of the pot. In the winter, water only once or twice a month, as the plant will go dormant and not need much water. In the summer, it will need more water, but be careful not to overwater.

Sea holly (Eryngium zabelii 'Big Blue') should ideally be grown in an area with full sun exposure. The species needs at least 6 hours of direct sunlight each day to not only thrive but also to produce its big blue blooms. Sunlight during midday when the sun is at its strongest will provide the most benefit, though a bit of shady morning or early evening sun is ok as well. Make sure to keep the plant away from trees, walls, or other structures which could potentially shade locations.

Sea holly should be pruned in late winter or early spring, before new growth begins. When pruning, remove any dead or damaged stems first. Then, to promote a bushy habit, cut the stems back by as much as 2-thirds of their original length. Be sure to leave some leafy growth at the top of the plant, as this will ensure the continued growth of healthy stems. Additionally, leave some basal shoots intact when pruning, as these will help keep the plant healthy in a seasonally changing environment.