# The One Module Tray for Starting 92% Of Crops (And Sowing Demo) Source: https://www.youtube.com/watch?v=BH3-nk9RceM Recap page: https://rapidrecap.app/video/BH3-nk9RceM Generated: 2026-01-22T12:34:13.164+00:00 --- ## Quick Overview The recommended module tray size for starting 92% of common crops like vegetables and flowers is the 40L (40-cell deep root) tray, which is ideal for plants with long tap roots like peas and squash, offering a balance between root space and efficient use of resources compared to smaller or larger cells. **Key Points:** - The presenter recommends the 40L (40-cell deep root) module tray for starting 92% of crops, including vegetables and flowers. - The 40L tray cells measure 4cm by 4cm in diameter, providing sufficient depth for root development. - Deep root trays like the 40L are superior for plants with long tap roots such as peas and squashes, preventing them from becoming root-bound before transplanting. - The speaker suggests using smaller trays for crops like lettuce and larger pots (7-9cm) for plants like kale that need more space before planting out. - When filling the tray, press the compost firmly but not too hard to ensure good seed-to-soil contact without compacting the soil excessively. - Use a permanent marker, like a Staedtler Lumocolor permanent pen, to label seed trays immediately to avoid losing track of what was sown. - The presenter demonstrates sowing peas into the prepared tray, recommending 3-4 seeds per module for better results when succession planting. ![Screenshot at 00:17: The presenter holds up a deep module tray, identified as the 40L size, to illustrate the ideal cell depth for starting many common crops.](https://ss.rapidrecap.app/screens/BH3-nk9RceM/00-00-17.jpg) **Context:** The video serves as a gardening tutorial focused on selecting the correct size of propagation module trays for starting seeds indoors. The presenter, standing at an outdoor wooden table surrounded by gardening supplies and a garden setting, compares various tray sizes (e.g., 28-cell, 40-cell, small pots) and explains how the cell depth and size should correspond to the specific needs of the plant being grown, such as root structure and desired planting schedule. ## Detailed Analysis The presenter advocates for using the 40L module tray, which features 40 cells measuring 4cm by 4cm, for starting the majority (92%) of crops, including vegetables and flowers. This deep root cell design is particularly beneficial for plants that develop long tap roots, such as peas and squashes, ensuring they have enough space to develop before being transplanted out, which avoids issues like being root-bound or overly stressed during the transplanting process. For plants that require less root space, like lettuce, smaller trays are suitable, while larger plants like kale might eventually require up-potting into 7-9cm pots. The tutorial emphasizes proper preparation: filling the tray with moist, peat-free compost (specifically mentioning SylvaGrow) and gently firming the compost to ensure good seed-to-soil contact without over-compacting, which restricts air and water movement. The presenter demonstrates sowing peas into the prepared tray, recommending planting 3-4 seeds per module for maximizing yield, especially when succession planting. Finally, the presenter stresses the importance of labeling the trays immediately using a permanent marker, like a Staedtler Lumocolor permanent pen, to track what was sown and when, preventing confusion later on. ### Module Tray Selection - The 40L (40-cell deep root) tray is the best choice for 92% of crops; it has 4cm x 4cm cells suitable for long tap roots like peas and squash. ### Alternative Tray Sizes - Smaller trays suit quick-growing or small-rooted plants (e.g., lettuce); larger 7-9cm pots are needed for plants like kale before planting out. ### Soil Preparation - Use peat-free, moist compost (like SylvaGrow) and gently press it into the modules to create firm contact without over-compacting, which hinders root growth. ### Sowing Technique (Peas Demo) - For peas, plant 3-4 seeds per module, slightly deeper than for smaller seeds, to maximize yield during succession planting. ### Labeling Importance - Always use a permanent marker (e.g., Staedtler Lumocolor permanent pen) to label trays immediately with crop type and sowing date to avoid mix-ups, as ink can fade over time. ### Watering Tip - Water gently using a fine spray bottle or fine-spout watering can (like those from Gardena) to avoid dislodging seeds or compacting the soil too much. ![Screenshot at 00:00: A person sowing seeds directly into rows in a dark, raised garden bed.](https://ss.rapidrecap.app/screens/BH3-nk9RceM/00-00-00.jpg) ![Screenshot at 00:05: The presenter standing outdoors, displaying various sizes of black plastic propagation trays on a wooden table.](https://ss.rapidrecap.app/screens/BH3-nk9RceM/00-00-05.jpg) ![Screenshot at 00:11: Close-up inside a greenhouse showing sprouted onions and pea seedlings growing in module trays.](https://ss.rapidrecap.app/screens/BH3-nk9RceM/00-00-11.jpg) ![Screenshot at 00:43: The presenter holding up two different module trays side-by-side to compare cell sizes \(12-cell vs. 100+ cell\).](https://ss.rapidrecap.app/screens/BH3-nk9RceM/00-00-43.jpg) ![Screenshot at 08:50: The presenter holding a small packet of seeds and preparing to sow them into the prepared module tray.](https://ss.rapidrecap.app/screens/BH3-nk9RceM/00-08-50.jpg)