How to Prepare Trays for Seed Starting

Starting your own seeds with Mosser Lee’s SucSeed™ is a great way to add variety to your garden, and optimize your garden blooms. Give your seedlings the best changes for vigorous growth.


How to prepare trays for seed starting

Project Difficulty


What You Will Need

  1. Your potting containers
  2. Scrub brush
  3. Dish soap
  4. Bleach
  5. Tap water
  6. Large bucket or utility sink
  7. Gloves


Starting your own seeds is a great way to add variety to your garden, and optimize your garden blooms.  Many people initially get into seed starting as a way to cut their planting costs but soon find a whole new world of options and methods to grow their garden. In this article we will share with you the basics to get started and offer a few suggestions perfect for the beginner and utilized by the experts. 

Selecting the right plant varieties for Seed Starting

Selecting seeds for your garden can be as simple or as intricate as your future gardening hopes can dream. No matter if you are planting as a fun science experiment with the kids, just hoping to get a few tomatoes this year or are cycling seedlings from a grow tent to a temporary green house in your back yard with packed excel spreadsheet full of data, there are just a few things to consider.

Invasive Plants

1. Will this plant add or subtract to the ecosystem of your community? Plants propagate, their entanglements with birds and bees can create volunteers throughout your community. If you plant a seed today, be prepared for when the seed eventually reproduces. Make sure to consider ornamental grasses and the consequences for potentially invasive plants. Some invasive type plants can be controlled in pots like herbs, and climbers, and are great additions to your planting schedule if done with consideration.

Check out the very popular Bradford Pear Tree as an example of well intentioned planting gone ary. Here is wonderful overview on the cautionary tale of the Bradford Pear. This pear tree was introduced in the 60’s as an ornamental tree by landscapers and became hugely popular. Over time this tree has chocked out native plants, and further contributed to the degradement of local ecosystems. A sterile cultivator of this tree (trees that don’t produce fruit) was introduced to try to curb the problem but found that those varieties can and do crosspollinate with other pear trees leading to new trees with the same crowding behaviors. Now you likely see many spring flowering trees that seem to be planted with no intention. Likely you are seeing an invasive pear, some communities are even offering incentives and replacement programs for the removal of Bradford Pear trees. Even so you will see see them for sale in some garden centers.

Seed Quality

2. Consider the quality of the seed. Seeds of low quality can produce a lower germination rate, decreased vigor, of mixed variety or even introduce weeds to your garden. Always record details like lot number, brand, and variety incase you run into a problem during this growing season or next. There are some wonderful seed companies dedicated to preserving heirloom varieties and even preserving historically and agriculturally important varieties. You can easily request a seed catalog to shop from reputable seed companies and are likely to even find a few in your state that can guide you to varieties that are better suited to your exact growing conditions.

Seedling Needs

3. Determine what is next for your seeds. A gardener is someone who is invested in the future. Gardening particularly the seed starting aspect of gardening is interesting because it’s where we merge time and nature.

Ask yourselves these questions:

  • When is the expected date of the last frost?
  • What kind of needs with the roots of this young seedling need?
  • Do I have enough space to keep these seeds thriving as they grow until I can plant them in their intended spot?
  • Will I need to repot them again before they are planted?

Make sure to align your seeds with their individual needs. Many gardeners like to depend on lists, and charts for reminders of when to plant what and which plants do best together.

Preparing your Pots and Seed Trays

There are many options for seed starting containers, and no one sizes or type will be perfect for every plant. Make sure to do a little reading on your seeds needs. In general plastic seed trays are a great choice for sowing most seeds. Seed trays often include a clear plastic top that helps to keep fragile seedlings from drying out and protected. You can also store them and use the over and over again. If the individual cells of the tray begin to deteriorate they are easy to replace. Check out our easy DIY solution for seed trays in our article “How to make a Windowsill Greenhouse. In this tutorial we will be using pots for convenience but you can effectively use this same method to prepare any container for planting.

Step 1: Gather your Seed Starting Supplies

Likely, your gardening tools have gathered some dust, they should be cleaned and maintained often like any other tool, make sure to clean any gardening tool, or container you may use before you plant. For this project you’ll need your potting containers, a scrub brush, dish soap and bleach, tap water, wash tubs to wash, rinse and sanitize your pots, or you can use a utility sink and tub combination. You may also want to use clean gloves as the bleach can really irritate your skin. When finished, your pots and trays will be ready for Mosser Lee’s SucSeed™ Seed Starter.

Step 2: Clean your Seed Starting Containers

Start by brushing away any loose soil or debris from your containers.

Then, prepare your containers to clean your pots. In the first tray or in a utility sink, add soapy warm water to thoroughly wash each tray or pot. Use an anti-bacteria dish soap and scrub brush to clean each tray or pot. Rinse each container in the second tray. You may need to change the water a few times. When finished, rinse the “rinse” tub.

Step 3: Sanitize your Seed Starting Containers

Now prepare your two tubs for sanitizing.

Fill one tub with plain tap water to rinse the pots after sanitizing and fill the other tub with 1 part bleach to 9 parts water for a sanitization bath.

Place your pots in the sanitization bath for 15 minutes. Each tub will need to have enough room to be submerged so you’ll need enough bleach mixture to completely cover each pot and soak for 15 minutes. In the bath pictured we did 2 cups of bleach and 18 cups of tap water.

After 15 minutes, place the pots or trays in the tub filled with tap water to rinse, then lay them out to dry on a clean towel to air dry.

Adding Soil to your Pots and Seed Trays

We recommend using Mosser Lee’s SucSeed™ to start your seeds. Check out the product page for more information on how to use SucSeed™ Seed Starter. SucSeed™ is THE Soil Starter to use for growing happy healthy seedlings. Make sure to check out our step by step tutorial on how to use SucSeed™.

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