How to Grow Delft Blue
Nigella papillosa
Your complete guide to growing Delft Blue.
📷 Wikimedia CommonsWhen to Plant Delft Blue
Planting windows vary by USDA hardiness zone. Look up yours by ZIP code.
| Zone | Start Indoors | Direct Sow | Harvest |
|---|---|---|---|
| Zone 1 | May – June | July – September | — |
| Zone 2 | April – May | June – August | — |
| Zone 3 | April – May | June – August | — |
| Zone 4 | March – April | June – July | — |
| Zone 5 | March – April | May – July | — |
| Zone 6 | March – April | May – July | — |
| Zone 7 | February – March | April – June | — |
| Zone 8 | February – March | April – June | — |
| Zone 9 | January – February | March – May | — |
| Zone 10 | January | February – April | — |
| Zone 11 | January | January – March | — |
| Zone 12 | January | January – March | — |
| Zone 13 | January | January – March | — |
Companion Plants for Delft Blue
✓ Good companions
Repels ants, aphids, and rodents that might damage bulbs
Repel aphids and other soft-bodied insects with their strong sulfur compounds
Toxic alkaloids deter rodents and deer from digging in the same area
Natural fungicide properties help prevent bulb rot and repel various pests
Deters rodents and rabbits that may dig up bulbs, while attracting pollinators
Repel aphids, whiteflies, and nematodes while attracting beneficial insects
Act as trap crops for aphids and cucumber beetles, drawing them away from hyacinths
Attracts beneficial insects like hoverflies and parasitic wasps that control pests
✗ Keep away from
Produces juglone which is toxic to many bulbous plants and inhibits growth
Competes aggressively for nutrients and may inhibit smaller bulb development
Spreads aggressively and can overwhelm delicate bulb plantings
