A Dark Opal basil plant with deep purple, serrated leaves, with a small pile of black seeds beside it

Clump of Dark Opal basil with deep purple foliage, grown in open ground on a hay mulch

Dark Opal Basil Seeds

Name: Dark Opal Basil Seeds
Brand: Kokopelli
Price: 3.9 EUR
Availability: InStock

3,90 €

1,30 € × 3 with no fees Klarna.

A basil with glossy purple foliage, Dark Opal combines an intense, slightly spiced fragrance with a colour that stands out on the plate.

The seeds are open-pollinated, organically grown, and saved for replanting. Sow on the surface from March to April, at between 20 and 25 °C, and harvest until the first frosts.

Vegetable seeds

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The summary

What you receive: a packet of Dark Opal basil seeds, organic and open-pollinated.
Seedling: from March to April under cover, sown on the surface, between 20 and 25 °C.
Germination: 5 to 10 days, faster than green basil.
The foliage: glossy purple, intense and slightly spicy fragrance.
The deciding factor: light, which directly controls the intensity of the colour.
How to choose: this one for colour, Vert de Gênes for pesto.

Purple basil with a spiced fragrance, heirloom seeds, for salads and vinegars

Dark Opal is instantly recognisable by its glossy purple foliage, which appears almost black when backlit. Its fragrance is intense and slightly more spiced than that of green basil, and its colour holds up equally well in a slow-cooked dish or a flavoured vinegar. You will find yourself reaching for it as much for appearance as for taste.

💜 Colour follows light

In full sun

The purple is deep and even, on the leaf as well as on the stem.

Semi-shade

The colour shifts to a bronze-green, and the fragrance fades along with it.

Indoors

Supplementary lighting makes all the difference, far more so than fertiliser.

Sow on the surface, in a pod

Like all basils, Dark Opal germinates in light: place the seed on a foam pod without covering it, press it down gently, and keep the temperature between 20 and 25 °C. A heat mat makes March sowing far more consistent, and the pod can then be placed directly into a grow bed.

✂️ Harvesting and pinching

Your weekly pinch, just above a pair of leaves, doubles the number of stems and delays flowering. With this variety, there is an extra reason to stick to it: the young leaves are the most colourful, and a plant you force to branch keeps producing them constantly. In a water-based system, Dark Opal behaves like its green cousin, with modest requirements and short roots that are well suited to a young system, but light becomes a key factor for success here, not merely for vigour. Vert de Gênes and the other herbs in the range are less demanding in this respect.

Technical specifications

The sachet

Seed origin: Association KokopelliOrganic seeds, royalty-free.
Seed type: Open-pollinated, non-hybridReproducible: seed from your own harvest will give the same variety.
Treatment: NoneNo GMOs, no coating, no chemical treatment.
Seed storage: Around 8 yearsStore in a dry, cool, dark place.

The variety

Botanical name: Ocimum basilicum var. purpureum
Foliage: Brilliant purpleThe colour follows directly from light exposure.
Fragrance: Intense, slightly spicy
Cycle: Annual, frost-tenderIt stops well before the frost.

Seedling and harvest

Seedlings under cover: March to April
Direct seedling: May to JulyOnce the frosts have passed.
Seedling depth: On the surfaceThe seed germinates in the light and should not be covered.
Germination temperature: 20 to 25 °C
Germination time: 5 to 10 days
Spacing: 25 cmBetween two plants, in a pot or a trough.

To budget for separately

Start-up heat: 1 seedling heat mat
Seedling medium: Foam pods or fine compost

8 further specifications are available in the detailed view.

In the box

1 paper seed packet of Dark Opal basil, harvested from organic farming
1 variety label: botanical name, sowing period, and year of seed harvest

Seedling data, temperatures and germination times: values recorded on 20/09/2026 from the seed supplier and two independent growing calendars. Heights, spacings and shelf lives are approximate figures for metropolitan France, not guaranteed values.

Dark Opal or Vert de Gênes

Our two heritage basils, same sachet size and same price. Colour, culinary use, and the warmth required at sowing clearly set them apart.

A purple basil and a green basil, two different growing methods One needs heat and sun to hold its colour; the other gets by in a temperate room. Have a look at what you have available.

	Foliage colour	Leaf size	Primary use	Seedlings under cover	Maximum germination time (days)	Minimum germination temperature (°C)
Dark Opal Basil SeedsYour choice	Bright green	Wide	Pesto and sauces	March to June	14 days	18 °C
Recommended Dark Opal Basil SeedsYour choice	Brilliant purple	Average	Plate garnish and vinegars	March to April	10 days	20 °C

Dark Opal Basil Seeds

The plant

Foliage colourBright green

Leaf sizeWide

Primary usePesto and sauces

The seedling

Seedlings under coverMarch to June

Maximum germination time (days)14 days

Minimum germination temperature (°C)18 °C

Dark Opal Basil SeedsRecommended

The plant

Foliage colourBrilliant purple

Leaf sizeAverage

Primary usePlate garnish and vinegars

The seedling

Seedlings under coverMarch to April

Maximum germination time (days)10 days

Minimum germination temperature (°C)20 °C

Both varieties have their own listing in the shop, with their growing schedule. Temperatures and germination times were recorded on 20/09/2026 from the seed supplier and two independent growing calendars, as approximate figures rather than guaranteed values.

Estimate your
delivery time

A packet of seeds ships as a small parcel. It can be grouped at no extra cost with the rest of your order, and the exact amount is calculated at checkout.

Frequently asked questions

6 questions

6 key questions

Why is my purple basil turning green?

Does it smell different from green basil?

How do you sow a purple basil seed?

When and how to pinch it out?

What can you do with purple leaves in the kitchen?

Does it grow as well as green basil in aquaponics?

Growing calendar

Reference points for mainland France, to be shifted by approximately two weeks depending on your region.

Stage
Seedlings under cover2 months	Seedlings under cover: no	Seedlings under cover: no	Seedlings under cover in March	Seedlings under cover in April	Seedlings under cover: no	Seedlings under cover: no	Seedlings under cover: no	Seedlings under cover: no	Seedlings under cover: no	Seedlings under cover: no	Seedlings under cover: no	Seedlings under cover: no
Direct seedling3 months	Direct seedling: no	Direct seedling: no	Direct seedling: no	Direct seedling: no	Direct seedling in May	Direct seedling in June	Direct seedling in July	Direct seedling: no	Direct seedling: no	Direct seedling: no	Direct seedling: no	Direct seedling: no
Weekly pinching out4 months	Weekly pinching out: no	Weekly pinching out: no	Weekly pinching out: no	Weekly pinching out: no	Weekly pinching out: no	Weekly pinching out in June	Weekly pinching out in July	Weekly pinching out in August	Weekly pinching out in September	Weekly pinching out: no	Weekly pinching out: no	Weekly pinching out: no
Harvest5 months	Harvest: no	Harvest: no	Harvest: no	Harvest: no	Harvest: no	Harvest in June	Harvest in July	Harvest in August	Harvest in September	Harvest in October	Harvest: no	Harvest: no

KeySeedlings under coverDirect seedlingWeekly pinching outHarvest

This month October

Growing guidance

Seedling depth: On the surfaceThe seed germinates in light and should not be covered
Germination temperature: 20 to 25 °CSlightly warmer than for green basil
Germination time: 5 to 10 days
Spacing: 25 cmBetween two plants, in a pot or a trough
Foliage: Brilliant purpleThe colour follows light exposure directly
Aspect: Full sunIn partial shade, the leaf turns bronze-green
Maintenance: One pinch per weekThe young leaves are the most colourful
Cycle: Annual, frost-tenderIt stops well before the frost
pH in aquaponics: 6.5 to 7.5The usual balance between fish, bacteria and plants
Seed storage: Around 8 yearsCommon reference point for basil, kept dry and away from light

What you need to know

Colour is never guaranteed — it has to be earned. A plant grown in full sun turns deep purple; the same plant in partial shade goes bronze-green, and the fragrance fades along with the colour.
Place the seed on the surface and press it lightly with your finger. Like all basils, Dark Opal germinates in light and will not emerge from under a centimetre of compost.
Pinch above a pair of leaves every week. On this variety, each cut does double duty: it multiplies the stems and encourages young leaves, which have the best colour.
Water at the base and in the morning. Leaf spots show up far more clearly on purple foliage than on green, and they start from evening watering that wets the leaves.
Opt for gentle cooking rather than high heat. The colour holds far better in a slow-cooked dish or a pickle than in a scorching pan, where it turns brown.
In aquaponics, its requirements are those of an ordinary basil: modest, with short roots, and tolerant of a young system. It is light that becomes the key success factor — not just for vigour, but for the crop itself.