Seed Swaps

Sea holly      

Eryngium planum

  • 45 plantings
  • 4 for swap
  • 6 wanted
  • 13 stashed

Sea holly is part of the Eryngium genus. Its scientific name is Eryngium planum.

Eryngium is a thistle type plant, that has spiky, purple, dull green leaves stems flowers and bracts.
It can tolerate drier conditions and poorer growing conditions than other border or cottage garden plants

Blooms appear in these approximate colours:   Purple taupe and   Hunter green and   Midnight blue. When mature, blooms are roughly 2.5 cm (that's 0.97 inches in imperial) in diameter. Leaves appear approximately as a   Hunter green and   Prussian blue

It is a flowering non-edible ornamental / flower that typically grows as a perennial, which is defined as a plant that matures and completes its lifecycle over the course of three years or more.

Sea holly is known for growing to a height of approximately 1.46 feet (that's 45.0 cm in metric) with a clump-forming habit. This plant tends to bloom in mid summer.

This plant is a great attractor for bees, so if you are looking to attract wildlife Sea holly is a great choice.

Consider Blue Hobbit, Blue Glitter, varifolium, Silver salantino and Blaukappe to grow as they are very popular with home gardeners.

Sea holly is normally quite a low maintenance plant and is normally very easy to grow - great for beginner gardeners!

This plant info is provided by the myfolia gardener's wiki. All details about Sea holly have been kindly provided by our members.

How to grow Sea holly

  • Full Sun

  • Low

Established clumps ca be divided in the spring

Try to plant in a location that enjoys full sun and remember to apply water fairly sparingly. Use Zone 4 - Zone 8 as your guideline for the appropriate climate for this plant. Keep in mind when planting that Sea holly is thought of as hardy, so this plant will survive close to or on freezing temperatures.

See our list of companion Plants for Sea holly to see which plants you should plant in close proximity to encourage growth.

Growing Sea holly from seed

Can be grown from seed but it easier to divide an established clump in the spring. Use potting compost mixed equally with vermiculite to improve drainage

Soil temperature should be kept higher than 10°C / 50°F to ensure good germination.

By our calculations*, you should look at sowing Sea holly about 56 days before your last frost date .

Transplanting Sea holly

Choose a bright sunny well drained position in the middle to the back of the border.

Ensure that temperatures are mild and all chance of frost has passed before planting out, as Sea holly is a hardy plant.

How long does Sea holly take to grow?

These estimates for how long Sea holly takes to sprout, grow and harvest are from real observations from real gardeners, right around the world.

Start logging and journaling your observations to participate!

Days to Germination How long does it take Sea holly to germinate?
75 days

Average 75 days | Min 75 days | Max 75 days (1)

Days to Transplant How long until I can plant out Sea holly?
+ 80 days

Average 80 days | Min 80 days | Max 80 days (1)

Days to Maturity How long until Sea holly is ready for harvest / bloom?
+ days

Average days | Min days | Max days (0)

Total Growing Days How long does it take to grow Sea holly?
= days

When should I plant Sea holly?

Our when to plant Sea holly estimates are relative to your last frost date.

Enter your frost dates and we'll calculate your sowing and planting dates for you!

When to sow The number of days to sow Sea holly before or after your last frost date.
56 days before Last Frost Date

Sea holly Etymology

The Latin word “Americana” means “of the Americas”.1

Other names for Sea holly

Blue sea holly, Eryngium

Eryngium planum L.

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