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Garden Care 5 min read

The Best Time to Plant Flowers on Long Island

Long Island's growing season is one of the most generous in New York State — a combination of the moderating influence of the surrounding ocean and Long Island Sound and a Zone 7 hardiness rating that reliably extends the window for both spring planting and fall lingerers. Knowing your frost dates and which plants go when is the key to maximizing color all season.

Long Island Frost Dates and Growing Season

Nassau County's average last spring frost is April 15–April 30, with the north shore coast running slightly later and barrier island communities like Long Beach running slightly earlier due to ocean warming. Average first fall frost falls between October 25 and November 5 for most of Nassau County. This gives Long Island gardeners roughly a 175–190 day growing season — excellent for the northeast.

Suffolk County's western towns generally match Nassau's dates, while the east end extends the growing season by 1–2 weeks in fall due to the buffering effect of Peconic Bay and the Sound. Bottom line: don't plant frost-sensitive annuals before May 1 in Nassau County and May 7 in most of western Suffolk.

Planting Calendar by Flower Type

**February–March (indoors):** Start petunias, impatiens, begonias, and snapdragons from seed indoors 8–10 weeks before last frost. Direct sow pansies and snapdragons outdoors in late February in sheltered spots.

**April:** Plant pansies, snapdragons, dianthus, and other cold-tolerant annuals outdoors. Plant bare-root roses and perennials. Division and transplanting of established perennials.

**May (after May 1):** Plant all frost-tender annuals — petunias, impatiens, marigolds, zinnias, begonias, coleus, geraniums, lantana. Warm soil and stable temperatures make May the most productive planting month.

**September–October:** Plant spring-flowering bulbs (tulips, daffodils, crocus, alliums). Divide and transplant summer perennials. Install trees and shrubs for fall establishment.

Best Annuals and Perennials for Long Island

For long-season color in Long Island's heat and humidity, top annual performers include Zinnias (full sun, drought tolerant once established, excellent for cutting), Angelonia (heat tolerant all summer), Vinca (tolerates heat and drought), and New Guinea Impatiens (shade tolerant unlike standard impatiens which has struggled with Impatiens Downy Mildew).

For perennials that reliably return on Long Island: Coneflower (Echinacea), Black-eyed Susan (Rudbeckia), Russian Sage, Coreopsis, Peonies, and Ornamental Salvias. Native asters bloom September–October, providing critical late-season color and pollinator support.

Frequently Asked Questions

When should I plant tulip bulbs on Long Island?
Plant tulip and other spring-flowering bulbs in October through early November on Long Island. Bulbs need 12–16 weeks of cold temperatures to bloom properly — planting in October ensures they receive adequate cold stratification through winter before spring emergence.
Can I plant impatiens on Long Island again now that they've come back?
Standard impatiens (Impatiens walleriana) suffered devastating losses from Impatiens Downy Mildew starting around 2012. The disease remains in Long Island soils and spores can survive multiple years. New Guinea Impatiens (Impatiens hawkeri) is immune to the disease and is the reliable shade-loving alternative. 'SunPatiens' (a New Guinea hybrid) handles sun and is outstanding for Long Island conditions.
What flowers bloom all summer in Long Island heat?
The best all-summer performers for Long Island include: Vinca (Catharanthus roseus) — heat and drought tolerant; Angelonia — virtually tireless in heat; Zinnias — full sun and drought tolerant; Gaillardia — native prairie plant perfect for hot sunny spots; and Portulaca for hot, sandy south shore conditions.

Conclusion

Long Island's Zone 7 climate gives you one of the longest growing windows in New York State. The key dates are May 1 for frost-tender plantings in Nassau County and October for fall bulb installation. Use these windows wisely and you can have color from April through November.

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