Quick Answer
The five cool-season crops that thrive in a Lexington backyard from late August through Halloween are: spinach (sown August 18), lettuce (sown August 20), radishes (sown August 25), kale (sown August 15), and arugula (sown August 22). Lexington's Zone 6a placement and inland cooling means you sow 5–7 days earlier than coastal MA towns. Top-dress beds with 2 inches of Compost before sowing.
1. Spinach — Sow August 18
Spinach germinates best in soil under 70°F — Lexington's mid-August soil hits that mark in the second week of the month. Sow Bloomsdale Long Standing or Tyee at ½" depth, ½" apart, in rows 12" apart.
For a 4×8 bed, allocate 6 sq ft to spinach for a steady fall harvest. Cut outer leaves once plants reach 4" — the crown keeps producing for 6 weeks.
2. Lettuce — Sow August 20
Loose-leaf and butterhead lettuces (Black Seeded Simpson, Buttercrunch, Red Sails) take 40–55 days to harvest in Lexington's fall conditions. Sow ¼" deep, thin to 6" spacing once seedlings have two true leaves.
Sow in successions a week apart — three plantings between August 20 and September 6 keeps lettuce coming through the third week of October.
3. Radishes — Sow August 25
Radishes are the fastest fall crop. French Breakfast, Cherry Belle, and Easter Egg varieties go from seed to harvest in 25–30 days. Sow ½" deep, thin to 1.5" spacing.
Plan two plantings, two weeks apart — late August and mid-September — for radishes through mid-October.
4. Kale — Sow August 15
Kale needs the most lead time of the cool-season set. Sow Lacinato (dinosaur), Red Russian, or Winterbor at ¼" depth by mid-August in Lexington — past August 25 you risk small plants going into frost.
Kale tastes sweeter after the first frost. With row cover, Lexington kale produces through Thanksgiving.
For the parallel garlic-planting timeline that runs alongside fall greens, see When Should I Plant Garlic in a Melrose Bed? — same Zone 6 logic applies in Lexington.
5. Arugula — Sow August 22
Arugula is fast (30 days) and tolerates Lexington's cooling September nights. Astro and Wild Rocket varieties handle light frost without bolting. Sow ¼" deep, broadcast thinly, thin to 4" spacing once seedlings establish.
Bed Prep Notes for All Five
For a 4×8 raised bed, plan on: - 0.3 cubic yards of Compost worked in 2" deep before sowing. - 0.1 cubic yards of Garden Soil Mix if the bed has lost height over summer.
Browse the Raised Garden Bed Materials collection for per-yard rates, and check the Lexington Landscape Supply page for delivery scheduling to East Lexington, Lexington Center, and Pierce's Bridge.
For the upstream cover-crop-or-compost decision before fall greens, see How to Plan a Fall Planting Schedule for a Cambridge Yard — Cambridge runs about a week behind Lexington's schedule.
Common Mistakes
- Sowing on a Cape Cod schedule. Lexington's inland cooling pushes the calendar 5–7 days earlier.
- Skipping the row cover. Floating row cover gets you through the first October frost.
- Forgetting to water. August soil dries fast — new seedlings need consistent moisture for 10 days.
For full MA fall vegetable variety recommendations, the UMass Extension Vegetable Program is the authoritative source.
