Dark Opal

Basil

Zone 6b Save Garden

🌱 60d to harvest Upright

Sink your senses into Dark Opal’s velvety, deep-plum leaves—an aromatic purple basil that perfumes the air with a rich, sweet-her…

Crop Dates

Milestone	Date
Start Indoors	Mar 14th
Last Frost	Apr 25th
Transplant / Sow Outdoors	Jun 20th
Harvest Begins	Aug 19th
Harvest Ends	Oct 16th

Crop Details

Trait	Value
Days to Maturity	60
Sun Requirements	Full Sun
Growth Habit	Upright
Support Needed	None
Planting Depth	Normal
Germination Temp (°F)	70
Min Soil Temp (°F)	60
Min Night Temp (°F)	50
Harden Off (days)	10

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Frequently Asked Questions

Why are my dark opal basil leaves turning black or developing blotches, and what should I do?

Basil (Ocimum basilicum) is prone to fungal leaf spots and downy mildew, especially when foliage stays wet. Water at the soil line and space plants for airflow, then remove badly infected leaves to slow spread. If conditions are humid, start a preventive regimen with a copper-based fungicide labeled for basil and apply according to the label’s timing and intervals.

How often should I water Dark Opal basil during peak growth (after it’s established)?

During its main growth phase, keep the top 1 inch of soil lightly moist but not soggy; basil roots need steady moisture with good drainage. In typical summer conditions, that’s often about 1–2 times per week, increasing frequency if the soil dries faster under full sun and containers. Water deeply to wet the root zone, and stop once water runs out of the bottom of pots to avoid root problems.

How do I know when Dark Opal basil is ready to harvest?

Start harvesting around day 60 when plants are well-leafed and reach about 8–12 inches tall, but you can take light “leaf pinch” harvests earlier to encourage branching. Harvest in the morning by snipping above a pair of leaves so the plant can produce new shoots. If flowering starts, harvest promptly and keep picking to maintain tender leaf quality and prevent bitterness.

Sink your senses into Dark Opal’s velvety, deep-plum leaves—an aromatic purple basil that perfumes the air with a rich, sweet-herbal fragrance. The foliage is tender and lush, with a softly serrated, slightly cupped texture that looks as sumptuous as it smells. Grow it for standout fresh garnishing, vibrant flavor in sauces and finishing swirls, and striking color that holds its beauty when dried or lightly roasted for bold, fragrant impact.

Sowing Tips

Transplant Conditions

Wait until soil reaches 60°F and nights stay above 50°F before moving outdoors. Harden off for 10 days first.

Expert Note

Start Dark Opal basil indoors for steady, compact growth, then transplant only once nights are consistently warm to preserve leaf color and vigor.