QIS™ Lilac
Consolida ajacis
Photo: Nit1994 · Wikimedia Commons · (CC BY-SA 4.0)
Features tall spires of dense florets. Plants produce lavender-colored, double blooms with a small percentage of singles. 1 1/2-1 3/4" florets on 9-12" flower spikes. Very similar to the Sublime series, which QIS™ replaced. Attracts hummingbirds.
Harvest
80-90d
Days to harvest
Sun
Full sun
Zones
1–11
USDA hardiness
Height
24-36 inches
Planting Timeline
Showing dates for QIS™ Lilac in USDA Zone 7
All Zone 7 flower →Zone Map
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QIS™ Lilac · Zones 1–11
Growing Details
Zone-by-Zone Planting Calendar
| Zone | Indoor Start | Transplant | Direct Sow | Harvest |
|---|---|---|---|---|
| Zone 3 | April – May | June – July | June – August | — |
| Zone 4 | March – April | June – June | June – July | — |
| Zone 5 | March – April | May – June | May – July | — |
| Zone 6 | March – April | May – June | May – July | — |
| Zone 7 | February – March | April – May | April – June | — |
| Zone 8 | February – March | April – May | April – June | — |
| Zone 9 | January – February | March – April | March – May | — |
| Zone 10 | January – January | February – March | February – April | — |
| Zone 1 | May – June | July – August | July – September | — |
| Zone 2 | April – May | June – July | June – August | — |
| Zone 11 | January – January | January – February | January – March | — |
| Zone 12 | January – January | January – February | January – March | — |
| Zone 13 | January – January | January – February | January – March | — |
Succession Planting
Direct sow every 3 weeks starting in early spring — once soil is workable and nights are reliably staying above 25°F — through early June. QIS Lilac runs 80-90 days to bloom, so a June sowing will still get you late-summer cuts before heat shuts the plants down. Stop sowing once daytime highs are consistently hitting 85°F; larkspur germinates poorly in warm soil and bolts fast once it's up.
For a continuous cut-flower supply, stagger 3 or 4 small sowings rather than one large one. A 10-foot row every 3 weeks is more useful than a 40-foot row all at once. In climates with mild falls, a September direct sow can work too — the seeds overwinter in the ground and germinate as soon as soil temps creep back above 50°F in spring.
Complete Growing Guide
Growing QIS™ Lilac (Consolida ajacis) flower. Light: Full sun. Hardy in USDA zones 1 to 11. Days to maturity: 80. Difficulty: Easy.
Harvesting
QIS™ Lilac reaches harvest at 80 - 90 days from sowing per Johnny's Selected Seeds. Expect 1 1/2-1 3/4" at peak. As an annual, harvest continues until frost ends the season.
This is an ornamental variety — not grown for harvest. Enjoy in the garden landscape.
Storage & Preservation
Fresh-cut QIS® Lilac flowers should be stored in a vase with cool water at room temperature (65-72°F) away from direct sunlight and ripening fruit, which emit ethylene gas. Keep humidity moderate to prevent petal browning. Cut flowers typically last 7-10 days. For preservation, air-dry spikes by hanging upside-down in a cool, dark, well-ventilated space for 2-3 weeks to retain color and shape. Alternatively, press individual florets between newspaper under heavy books for dried arrangements. Silica gel drying preserves color brilliance and is ideal for crafting.
History & Origin
QIS™ Lilac is open-pollinated, meaning seed saved from healthy plants will produce true-to-type offspring. Listed in the Johnny's Selected Seeds catalog.
Consolida ajacis is an annual flowering plant of the family Ranunculaceae native to Eurasia. It is widespread in other areas, including much of North America, where it is an introduced species. It is frequently grown in gardens as an ornamental for its spikes of blue, pink or white flowers. It may reach a meter in height. Since the aerial parts and seeds of C. ajacis have been found to contain diterpenoid alkaloids, including the highly toxic methyllycaconitine, the plants should be considered as poisonous.
Advantages
- +Tall dramatic spires create stunning vertical interest in garden borders.
- +Attracts hummingbirds, adding wildlife appeal to ornamental plantings.
- +Double blooms on most plants provide fuller, more luxurious flower appearance.
- +Easy growing difficulty makes it ideal for beginner gardeners.
- +80-90 day maturity allows multiple succession plantings per season.
Considerations
- -Requires cool temperatures; struggles in hot, humid climates.
- -Tall 9-12 inch spikes may need staking in windy locations.
- -Relatively short vase life compared to other cut flower varieties.
Companion Plants
Lavender and catmint are the most natural pairings here. Both prefer the same lean-to-moderate soil and full sun that larkspur wants, so neither is pulling from the other's plate. They also draw in parasitic wasps and hoverflies — the kind that prey on aphids, which love to cluster on larkspur's soft new growth once temps climb past 70°F.
Alliums (ornamental chives, garlic, onion sets) are worth tucking nearby. The sulfur compounds they release through roots and foliage genuinely disrupt soft-bodied pests like aphids and spider mites — this isn't folk wisdom, it's a documented feeding deterrent. French marigolds (Tagetes patula specifically, not the big African types) pull similar duty with shallower root systems that won't crowd larkspur's taproot. Roses and peonies are good neighbors mostly in the calendar sense: they hit peak bloom on a similar early-summer schedule and make a cut-flower bed feel intentional rather than thrown together.
Black walnut trees are the hard no. Juglans nigra produces juglone, an allelopathic compound that persists in the soil well past the tree's drip line and hits Consolida hard — expect poor germination and stunted seedlings anywhere in that zone. Large maples and eucalyptus are a separate issue entirely: neither produces juglone, but both run dense, shallow root networks that will out-compete larkspur for moisture in any dry stretch, regardless of how much you water.
Plant Together
Lavender
Attracts beneficial pollinators and repels pests with similar growing requirements
Catmint
Deters aphids and ants while attracting beneficial insects
Alliums
Natural pest deterrent that repels aphids and other soft-bodied insects
Marigolds
Repel nematodes and aphids while attracting beneficial predatory insects
Hostas
Provide complementary foliage texture and thrive in similar partial shade conditions
Roses
Share similar soil preferences and lilacs may help deter some rose pests
Peonies
Compatible growing conditions and complementary bloom times
Clematis
Can climb through lilac branches providing extended bloom season
Keep Apart
Black Walnut Trees
Produce juglone which is toxic to lilacs and inhibits their growth
Large Maple Trees
Create too much shade and compete aggressively for water and nutrients
Eucalyptus
Releases allelopathic compounds that inhibit growth of nearby plants
Pests & Disease Resistance
Common Pests
Aphids, spider mites, whiteflies
Diseases
Powdery mildew, root rot in poorly drained soil
Troubleshooting QIS™ Lilac
What you'll see, why it happens, and what to do about it.
White powdery coating on leaves and stems, usually appearing mid-season when plants are crowded or nights turn humid
Likely Causes
- Powdery mildew (Erysiphe cichoracearum) — a fungal disease that thrives in warm days and cool, humid nights
- Poor airflow from spacing plants closer than 12 inches
What to Do
- 1.Thin plants to at least 12 inches apart so air can move through the canopy
- 2.Spray affected foliage with a diluted baking soda solution (1 tablespoon per gallon of water) or a potassium bicarbonate product — apply early morning so leaves dry before nightfall
- 3.Pull and bin heavily infected plants; don't compost them
Stems collapsing at the soil line, with lower foliage turning yellow and the whole plant wilting even when soil is moist
Likely Causes
- Root rot from Pythium or Phytophthora — both are waterborne pathogens that move fast in compacted or poorly drained beds
- Overwatering or beds with no drainage amendment
What to Do
- 1.Pull the affected plant immediately — there's no saving it once the crown is gone
- 2.Let the surrounding soil dry out for several days before watering again
- 3.Before replanting in the same spot, work in 2-3 inches of coarse compost or perlite to break up compaction and improve drainage
Frequently Asked Questions
How long do QIS® Lilac cut flowers last in a vase?▼
Can I grow QIS® Lilac flowers in containers?▼
When should I plant QIS® Lilac seeds?▼
Is QIS® Lilac good for beginners?▼
How do I dry QIS® Lilac flowers for arrangements?▼
What makes QIS® Lilac different from Sublime series flowers?▼
Growing Guides from Wind River Greens
Where to Buy Seeds
Sources & References
External authority sources used in compiling this guide.
- BreederJohnny's Selected Seeds
See the Methodology page for how this data is sourced, what's AI-assisted, and known limitations.