What to plant in September

September is the primary planting window for spring-blooming bulbs (zones 3–6 in late September), garlic (zones 5–8), and the late-season cool-season vegetable garden (spinach, lettuce, beets, turnips in zones 6–9). In zone 9–10, September is the best month to start the entire co

September is one of the most productive planting months of the year for a different reason than spring: what you plant now will feed you in fall and deliver flowers next spring. Garlic goes in. Bulbs go in. The cool-season garden accelerates. Miss this window and you'll be wishing for it in April.

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September planting by category

Spring-flowering bulbs

The window: In zones 3–6, plant spring-flowering bulbs in September–November after soil cools below 50°F but before it freezes solid. Per Penn State Extension, "bulbs planted when soil is still warm (above 60°F) are prone to early growth and winter killing."

In zone 7 (Long Island), I typically start planting tulips and daffodils in late September or early October — when soil temperatures have dropped to the 50–55°F range. Earlier than that, and tulip bulbs rot; later than November, and the ground may be too hard to dig.

Tulips (Tulipa spp.): Plant 6–8 inches deep, 4–6 inches apart. Per Missouri Botanical Garden, "tulips need 12–14 weeks of cold (below 40°F) to bloom." In zone 7+, this cold period occurs naturally. In zones 8–9, pre-chilled tulip bulbs must be used.

Daffodils (Narcissus spp.): Plant 6–8 inches deep, 4–6 inches apart. Daffodils are one of the most deer-resistant spring bulbs — per Rutgers NJAES, daffodils are listed as "rarely damaged" because all parts of the plant contain toxic alkaloids (lycorine). I plant daffodils extensively in my zone 7a beds specifically because deer leave them alone.

Alliums (Allium spp.): Large ornamental alliums (A. giganteum, A. 'Gladiator', A. 'Purple Sensation') are planted 6–8 inches deep in fall for late-spring bloom. Alliums are another deer-resistant choice — the smell deters browsing. I grow several allium varieties throughout my zone 7a beds with zero deer damage.

Hyacinths (Hyacinthus orientalis): 4–6 inches deep. Fragrant spring bloom. Hardy zones 4–8.

Crocus: 3 inches deep. Earliest spring bloom. Hardy zones 3–8. Plant in drifts of 25 or more for visual impact.

Scilla siberian (Scilla siberica): 3–4 inches deep. Brilliant blue small flowers in early spring. Naturalizes readily. Hardy zones 3–7.

Garlic — the most important September planting

Per Penn State Extension, "garlic planted in October in zones 5–7 produces larger bulbs than spring-planted garlic." Most recommendations say October for zones 6–7, but zone 8 gardeners plant as early as September.

Hardneck vs. softneck:

• Hardneck varieties ('Chesnok Red', 'German Red', 'Music'): Best flavor, produce scapes in June. Per Penn State Extension, "hardneck garlic is best for zones 4–7 where cold winters trigger proper bulb development."
• Softneck varieties ('California White', 'Inchelium Red'): Longer shelf life, milder flavor. Better for zones 7–9.

Planting: Break heads into individual cloves. Plant pointed tip up, 2 inches deep, 6 inches apart, in rows 12 inches apart. Per Penn State Extension, "apply 2–3 inches of mulch over planted garlic to protect from freeze-thaw cycles."

In my zone 7a beds, I plant garlic in mid-October after bulb planting is complete. The garlic shoots emerge by late October or November, survive winter under mulch, and are harvested the following July.

Cover crops

September is the prime window for planting fall cover crops in zones 4–7.

Per University of Minnesota Extension, "cover crops planted in September have time to establish before winter and provide significant soil benefits." Options:

• Winter rye (Secale cereale): Fastest to establish, most cold-hardy. Germinates at soil temperatures as low as 34°F. Sow 2 lbs per 1,000 sq ft. Excellent erosion control and organic matter addition.
• Crimson clover: Fixes nitrogen. Survives zone 6+ winters. Sow before September 15 in zone 6 for reliable winter survival.
• Oats: Quick cover; winter-killed in zones 5–6, providing a mat of organic matter without needing to be tilled under.
• Annual ryegrass: Fast establishment, good erosion control. Winter-killed in most zones.