We proudly research, grow, and write about our plants by hand. Descriptions are based on our experience as well as information gathered from reputable sources: books, periodicals, and select websites. Should you have questions beyond what is listed please email or call.

A close-up of Eryngium amethystinum, also known as amethyst sea holly, with its thistle-like purple flowers.

An image of Eryngium amethystinum, also known as amethyst sea holly, with its thistle-like purple flowers and silver-green foliage.

Eryngium amethystinum | amethyst sea holly

Regular price: $8.99
Regular price
Sale price: $8.99

Shipping calculated at checkout.

Grown from seed in living soil without the use of pesticides, chemicals, or carbon fuels.

Available FALL 2026. Sign up for the waitlist to be notified when available for purchase.

Amethyst Sea Holly (Eryngium amethystinum) is a compact perennial with spiky blue-violet summer blooms and silver-speckled grey-green waxy leaves. Pollinators adore the unusual flowers throughout the growing season. Dried flowers lend interest to the winter garden and are a boon to the birds.

Happiest in full sun on poor, sandy soils but tolerates a wide range of conditions.

Deer, rabbit, and drought resistant. Salt tolerant.

Zone: 4 to 8(9)
Family: Apiaceae
Type: herbaceous perennial
Height: 12 to 24 (possibly 30) in.
Spread: 12 to 24 in.
Exposure: full sun
Conditions: dry, well-drained, average
Bloom Time: July to August
Native Range: Mediterranean
Common Names: Italian eryngo, amethyst eryngo, amethyst sea holly

4" pot

Special Characteristics

Deer-resistant
Drought resistant
Salt tolerant
Pollinator favorite
Winter interest
Silver foliage
Cut-flower

image credits

Ziegler175,CC BY-SA 4.0, via Wikimedia Commons
Enrico Blasutto,CC BY-SA 3.0, via Wikimedia Commons

Ordering information

Preorders

You may place your order anytime to reserve plants for fall 2026 shipping. If you place multiple orders, we will combine plants into one box (or as many as needed) and any extra shipping charges will be refunded.

We will resume shipping as soon as temperatures cool in our location and yours. This can range from the beginning of September for northern locations to the end of October for hot locations (Texas).

We will check in with you a week before shipping to make sure you receive your plants at a time that is convenient for you.

Shipping

Live plants ship in spring and fall only. Plants may ship dormant, depending on variety and season. Shipping costs are most reasonable when bundling like size plants.

4-inch: 1-6 plants ship for $15.00 / 7-13 plants ship for $18.00 / 14-30 plants ship for $40.00
1-gal: 1-2 plants ship for $18.00 / 3-4 plants ship for $25.00 / 5-6 plants ship for $40.00
trees & shrubs: $27.00-$40.00 each, height dependent
seeds: $6.75 or free with orders over $15.00

We regret that we cannot ship internationally or to the following states: AK, AZ, CA, CO, FL, HI, ID, MT, NV, OR, UT, or WA.

Nursery pick up

We will email you to schedule a day and time to collect your plants when they are ready in spring. Generally, plants can be collected from the nursery Monday through Sunday from 10am-4pm in Spring, Summer, and Fall.

Plant Sizes

We most commonly use the following pot sizes for perennials:

4-inch pot: 3.5" H x 3.5" W x 3.5" D
2-quart pot: 6" H x 5.25" W x 5.25" D
1-gallon pot: 6.87" H x 8" Dia (this is a true one gallon pot, not the smaller 'trade' one gallon pot used by many nurseries)

Check out our illustrated pot size guide here.

Representative trees & shrubs are photographed in their pots and posted on each plant page.

Sustainability

Sustainability is at the heart of what we do at The Old Dairy. We grow all of our plants outdoors without the use of chemicals, fertilizers, carbon fuels, or peat.

Many of our perennials are grown in the ground and dug upon order (this is especially true for larger sizes). This practice allows us to grow stronger, healthier plants using native soil, and ultimately reduces our impact on the environment.

Our open-pollinated seeds are collected from plants in our mother beds, which have never been treated with chemicals or sprays of any kind.

Read all about our sustainable practices here.