Heirloom Organic Blue Sea Holly Flower Seeds (20)
Eryngium flowers seeds
Looking for a fascinating addition to the garden? Then why not consider growing sea holly flowers (Eryngium). Sea hollies can provide unique interest with their spiny-toothed leaves and clusters of teasel-like blossoms. They also offer versatility with their wide range of growing conditions and various uses in the garden. What is Sea Holly? Eryngium plants, also known as sea holly flowers, make striking additions to the garden. Mostly native to Europe and the Mediterranean, these plants generally grow anywhere from 18 to 36 inches (45-90 cm.) tall with a one foot (30 cm.) spread. Their green or silvery-blue stems give way to green or blue cones surrounded by spiky silver, white, green, blue or violet bracts, which bloom from summer throughout fall.
What is Sea Holly? Eryngium plants, also known as sea holly flowers, make striking additions to the garden. Mostly native to Europe and the Mediterranean, these plants generally grow anywhere from 18 to 36 inches (45-90 cm.) tall with a one foot (30 cm.) spread. Their green or silvery-blue stems give way to green or blue cones surrounded by spiky silver, white, green, blue or violet bracts, which bloom from summer throughout fall.
Holly plants (Eryngium) are low-maintenance and produce striking purple-blue flowers that look like small glowing thistles. They are very similar to globe thistle (Echinops), but sea holly flowers have green or blue cones and a distinctive bract collar in silver, white, green or bluish-purple. The colors often look almost metallic and painted on and can change in the sunlight. Sea holly plants can have green or silvery-blue stems. The leaves can be long and thin, deeply lobed, or even round, depending on the variety. The plants are very tolerant of dry conditions and also handle salt spray with ease.
Growing From Seeds
Most sea holly varieties can be started from seed. They do best if stratified first. The easiest method is to direct sow in the fall and then be patient and wait to see what sprouts in the spring. But you could start sea holly seeds indoors if you chill them for about four weeks in the refrigerator and then move them out to germinate in about two to three weeks.
Botanical Name Eryngium species
Common Names Sea holly, Miss Wilmott's ghost, rattlesnake master, button snakeroot
Plant Type Perennial flower
Mature Size 6 to 18 inches
Sun Exposure Full sun
Soil Type Sandy
Soil pH 6.5 to 7.5
Bloom Time Summer to fall
Flower Color Green, blue, blue-purple, silver, white
Hardiness Zones 4, 5, 6, 7, 8, 9
Native Area Europe and Mediterranean countries
How to Grow Sea Holly
Flowering starts in mid-summer and will continue into the fall. You will enjoy how low-maintenance they are as they don't like excessive water and fertilizer and they also don't like to be moved. Sea holly will bloom longer if you deadhead the spent flowers, but they look wonderful long into winter, so leave the fall flowers on the stems. The birds will thank you.
This is a great flower for all those spots in the garden where the hose doesn’t reach or in that strip of grass between the sidewalk and the street. But don’t confine it there. The blues and silvers blend well with just about every color, especially yellow and orange. Pair it with rudbeckia, coreopsis, zinnia, and cosmos. The tall varieties need some support and planting them behind sturdy plants, like coneflowers, will help keep them standing.
Sea holly is popular with bees and butterflies, but not with deer and rabbits. The flowers last several days in a cut flower arrangement.
A full day of sun will give you’re the strongest sea holly plants and the most blooms. They can handle a bit of partial shade, but weaker stems will result making staking necessary to keep the plants standing upright.
Sea holly is not particular about soil pH. Anything around the neutral range is sufficient. However, the plants need good drainage or they will die off.
Once established, sea holly is very drought tolerant and won’t need additional water unless subjected to a prolonged, hot, drought. Sea holly has a long taproot. This makes it very drought tolerant, but it also means it is getting its water from deep in the soil and surface moisture will just allow the crown to rot.
Temperature and Humidity
Most sea holly species are reliably perennial in USDA Hardiness Zones 4 to 9. Although they can be more difficult to grow in areas with cold, wet winters, if you can get them established, you should have good luck with them.
Sea holly is not a heavy feeder, but you should still make sure your soil has plenty of organic matter in it. If not, you will need to feed or side dress with compost in mid-season.
Propagating Sea Holly
Because sea holly has a tap root, it does not divide easily. You can, however, take root cuttings in the spring. Sea holly transplants easily as seedlings, but it becomes more difficult as the plants mature, which is why you don’t see a lot of them in plant nurseries. If you want to move volunteers (seedlings that sprout up on their own), do it early.