When to Plant Zinnias in New Jersey
The cut-and-come-again champion. The more you cut zinnias, the more they bloom. A cottage garden essential.
The Short Answer
New Jersey Frost Dates
Your planting dates depend on which part of New Jersey you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Northern New Jersey | 6a, 6b | Apr 20 - May 5 | Oct 5 - Oct 20 |
| Central New Jersey | 6b, 7a | Apr 10 - Apr 25 | Oct 15 - Nov 1 |
| Southern New Jersey | 7a, 7b | Apr 1 - Apr 15 | Oct 20 - Nov 5 |
Zinnias Planting Schedule for New Jersey
Northern New Jersey (Zones 6a, 6b)
Average last frost: Apr 20 - May 5 · Average first frost: Oct 5 - Oct 20
Central New Jersey (Zones 6b, 7a)
Average last frost: Apr 10 - Apr 25 · Average first frost: Oct 15 - Nov 1
Southern New Jersey (Zones 7a, 7b)
Average last frost: Apr 1 - Apr 15 · Average first frost: Oct 20 - Nov 5
Growing Zinnias in New Jersey
Zinnias in New Jersey's Climate
Your warm, humid summers grow zinnias prolifically. Direct sow from mid-May. Powdery mildew is the main issue in humid conditions — water at the base, never overhead, and choose mildew-resistant varieties. Cut or deadhead regularly for continuous bloom through frost.
Soil Considerations for New Jersey
Sandy soils in Pine Barrens. Clay in north. Acidic in south. Rich loam in central agricultural areas. The Garden State for good reason. Make sure soil has warmed to at least 60°F before planting zinnias outside.
New Jersey Climate & Growing Season
Moderate climate with maritime influence. Good growing season. Four seasons. Excellent for a wide range of crops. Zinnias cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.
Growing season length varies across New Jersey: Northern New Jersey (6a, 6b) has a last frost around Apr 20 - May 5, while Southern New Jersey (7a, 7b) sees frost end around Apr 1 - Apr 15. This difference matters for zinnias — transplant timing shifts by several weeks across the state.
Growing Tips
Water at the base to prevent powdery mildew. Cut flowers just above a leaf node to encourage more branching and blooms.
Companion Planting
Plant zinnias alongside these companions for better growth:
The Bottom Line
Last reviewed: March 29, 2026