Lettuce & Other Leafy Greens Grow Guide

Updated

Grow any variety of leafy green in the Flex Farm using this Grow Guide. 

Quick Facts

Where can you purchase?: Salad Greens Seed Bundle or Essential Seed Bundle

Days to Transplant: 4-7 days

Days to Harvest: 28 days

Target Nutrient Level (TDS): base number + 700

Nutrient Type: Flex Farm Nutrients

Target pH Level: 5.5-6.5

Light: 18 hours per day

Temperature: 65-75 degrees Fahrenheit

Planting Pattern: Checkerboard pattern

Harvesting Method: Full plant harvest

Dowels Recommended?: No

Alternative Bundles to try growing: Global Brassicas & Power Greens

Plant Guide

🌱 Planting Seeds & Transplanting

Follow our Planting Seeds and Transplanting Guide for general best practices.

  • Avoid leggy plants by introducing seeds to bright, direct light the day they emerge from their seed casing. Lettuce germinates in 2-3 days. Freshly germinated lettuce seeds look like this:

Pelleted lettuce seeds cracked open, each seedling curling out of its seed casing

  • The photo above shows pelleted lettuce seeds. Notice that the pellet has cracked open and the seedling is curling out of the seed casing. This is the perfect time to remove the humidity dome and place the seedlings under direct light. Make sure they have plenty of water to grow.
  • Germinated seedlings may receive a light nutrient-rich water solution. Mix 1 tsp of Nutrient A & Nutrient B in one gallon of water. Pour water into the bottom of the nursery tray.

The Flex Micro can help grow big seedlings with minimal effort and legginess.

Not all seeds germinate. This is why you should plant a few extra seeds every time. Seeds provided by Fork Farms have a 98% germination rate.

  • Growing in the Flex Farm: To achieve the "checkerboard" pattern, plant 150 seeds. This covers all 144 open plant spaces. 
  • Growing in the Flex Acre: To achieve the "checkerboard" pattern, plant 580 seeds. This covers 576 open plant spaces.

These lettuce seeds will typically take 2-3 days to sprout and 4-7 days till they are ready to transplant. The recommended planting pattern mimics a checkerboard. Every other plant space will host a seedling, and the other spaces will hold panel plugs. 

Checkerboard planting pattern on Flex Farm panels, with a seedling in every other space and plugs in the rest

🌿 Maintenance

Follow our Maintenance Guide grow video for general best practices. 

Water Quality

Follow our Checking & Adjusting pH & Nutrient grow video for general best practices. 

Besides adequate water flow, nutrients and pH levels are the most important part of growing in the Flex Farm and Flex Acre. When your pH and TDS are on point, your crop will be fresh, abundant, and delicious.

pH: 5.5-6

Nutrients: Base + 700 = target TDS

  • "Base" means the mineral content of your water source before nutrients are added. Capture a water sample and use the TDS meter to determine your "base".
  • 1 TBSP of Nutrient A and 1 TBSP of Nutrient B raises the nutrient content by approximately 230ppm.
  • 100 ppm above or below your target TDS is an acceptable range for growing lettuce. 

Use our Maintenance Checklist, Data Log, and Quick Reference Guide on Farmative to manage maintenance tasks. 

Harvesting:

Follow our Harvesting Guide for general best practices.

Lettuce is ready to harvest after 21-28 days. 

Supplies needed for harvest:

  • Clean food storage bins
  • Clean working surfaces (table)
  • Gloves
  • Garbage bin
  • Handwashing station

How to harvest lettuce:

  1. Unplug the pump.
    1. This helps minimize messes.
  2. Wash hands with soap and warm water and wear food-safe gloves.
    1. We highly recommend using food safe gloves while harvesting. If you touch anything other than the plants or clean working spaces, you will need to re-glove before continuing to harvest.
  3. Reach toward the base of a plant and carefully pull the plant out of the plant space. 
  4. Gently separate the roots from the plant base. 
  5. Set the plant on the clean working space or clean food storage bin. 
  6. Place the roots in the garbage bin.
  7. Repeat until all plants are harvested. 
  8. Once all plants are harvested, refrigerate the greens immediately. When properly stored, the greens can last up to 4 weeks. 

Freshly harvested heads of lettuce from a Flex Farm

Planning Successions

Succession planting is a strategic way to plan consistent harvests in a reliable cadence.  

The key to maintaining successful successions is preparing transplant-ready seedlings just in time for your next harvest. Lettuce is ready to transplant 6-8 days after seeding. If lettuce is ready to harvest next week, it is best to plant seeds today. This way, new seedlings can be transplanted immediately after harvesting.