Grand Rapids TBR

Lettuce

Zone 4b Save Garden

Botanical illustration of Grand Rapids TBR

🌱 45d to harvest Rosette

Crisp, cool, and vividly fresh—Grand Rapids TBR delivers tender leaves with a clean, sweet bite and a satisfying crunch that feel…

Crop Dates

Milestone	Date
Start Indoors	Apr 15th
Last Frost	May 13th
Transplant / Sow Outdoors	May 13th
Harvest Begins	Jun 27th
Harvest Ends	Sep 27th

Crop Details

Trait	Value
Days to Maturity	45
Sun Requirements	Full Sun
Growth Habit	Rosette
Support Needed	None
Planting Depth	Surface
Germination Temp (°F)	45
Min Soil Temp (°F)	40
Min Night Temp (°F)	30
Harden Off (days)	6

Recommended Companions

Frequently Asked Questions

What pest or disease is most likely to hit Lactuca sativa (Grand Rapids) and how can I manage it?

Look out for aphids, which cluster on tender lettuce leaves and leave sticky honeydew that can lead to sooty mold. Rinse plants with a strong jet of water early in the morning and, if needed, apply insecticidal soap directly to the undersides where aphids concentrate. Keep spacing airy and remove badly infected leaves promptly to reduce spread of foliar problems like downy mildew.

How often should I water Lactuca sativa during the main growing phase to keep it from getting bitter?

During the ~45-day grow-out, keep the top 1–2 inches of soil consistently evenly moist, aiming for frequent light watering rather than long dry spells. In full sun, check daily and water when the surface starts to dry, typically about 1 inch per week total (adjusting for heat and soil type). Avoid water stress because lettuce that dries out then gets hot can turn bitter and bolt faster.

How do I tell when Grand Rapids lettuce (Lactuca sativa) is ready to harvest?

Harvest when heads/forms are firm and the leaves are fully sized, about 45 days from sowing under good conditions. For best flavor, pick in the morning once leaves are crisp, before the plant bolts or starts stretching upward. If you’re doing cut-and-come-again for leaf lettuce habits, harvest outer leaves when they reach usable size without stripping the center.

Crisp, cool, and vividly fresh—Grand Rapids TBR delivers tender leaves with a clean, sweet bite and a satisfying crunch that feels alive in the garden. The loose-leaf heads form an open, upright rosette of bright green foliage, with a lightly ruffled texture that stays pleasantly crisp for harvest. Ideal for fresh salads and vibrant garnishes, this dependable 45-day variety is a favorite for gardeners who want reliable, flavorful greens all season long.

Sowing Tips

Transplant Conditions

Wait until soil reaches 40°F and nights stay above 30°F before moving outdoors. Harden off for 6 days first.

Expert Note

For best frill and crunch, keep lettuce evenly moist and transplant/plant during cool weather to avoid bitterness and bolting.