Seed Starting 101 - Easy Steps to Seed Germination

By on February 18, 2011

Veggie transplants ready to go in the ground

Seed starting is easier than you think. There’s nothing to be afraid of if you follow our simple steps.

A lot of gardeners will back away slowly when the conversation turns to seed trays and heating mats, and they start muttering things like, “I just buy organic seedlings from my local nursery.”

That’s one way to go.

But to get the most out of your gardening dollar you cannot beat starting vegetables and flowers from seeds. Plus (and this is what motivates many gardeners) you can choose exactly the vegetable variety or much-loved flower that you want.

In our video, Seed Starting,, Tricia walks you through the seed starting process and explains the different equipment options. Your major decisions will be: when to start your seeds, what to plant them in, and how to provide an environment for germination.

Chard in a Speedling Tray

Chard starts in a Speedling tray are almost ready to be transplanted out.

Timing your seed starts

If you already have your seeds in hand, check your seed packet for germination times and read the instructions on when the plant should be transplanted. For example, squash is sensitive to getting rootbound so it should be started 3-4 weeks before the last frost in a larger container. Tomatoes and peppers need longer times and are typically started 6-8 weeks before the last frost. If you’re doing cool weather veggies, some of them, like broccoli and cauliflower, should be set out BEFORE the last frost.

Still making up your mind? Here’s a chart from North Carolina State University with germination times for popular vegetables and flowers. Take that germination time and add it to the time the seedling will be reared indoors.

The date of the last frost in your area is crucial. Planting your seedlings outdoors before the last frost typically leads to heartbreak when the seedlings are zapped by a cold snap. So please, don’t try to jump the gun on that outdoor planting date.

Count back from the last frost date to calculate when to start your seeds. Get the last frost date from your local Master Gardeners or Cooperative Extension office. In California you can find your Master Gardeners by county with this site. There’s a national map too, to guide you to your local Cooperative Extension and Master Gardeners.

Cowpot ready to be planted

This tomato in a Cow Pot is ready to be transplanted out into the garden.

How to choose a seed starting container

Seeds can be started in just about anything, including eggshells and paper milk cartons.

Some of our favorite re-usable trays are:

Speedling trays have their own insulation and are designed to air-prune the roots. These trays are favorites with farmers because they last for years. I’ve seen ten-year-old Speedling trays still in service and looking great.

Standard plastic trays are easy to work with and very durable.

The bio-degradable route is a great option for sustainability:

To minimize transplant shock, try Soil Blockers This innovative method doesn’t use a container at all, just a compressed block of media. Roots are air-pruned and the block is dropped right in the ground. For more info on this method check out our video.

CowPots that are made from manure and can go straight into your garden soil. Their cousins coco peat pellets, and coco fiber pots are some other marvelous options.

Another fun biodegradable option is the Pot Maker. This little tool makes great biodegradable pots from newspaper.

Fill your containers with a soilless mix, like our organic QuickRoot, place your seeds two to a cell (Tricia likes to use the Widger as a seed spoon), and water well with a fine spray. Our classic Haws watering can has a removable “rose” on the spout that will sprinkle your seeds and seedlings with droplets. Make sure your seeds and seedlings get a continuous supply of water. If they dry out during germination they will die.

Lettuce in a soil block

This lettuce is in a soil block.

Do you need an additional heating source for your seedlings?

Using Speedling trays, with their built-in insulation, means you don’t need a heating mat but can simply put the trays in a warm place (like the top of the refrigerator).

Heating mats will help with all other containers—including soil blocks, which are set onto undivided trays. If you’re new to seed starting and just want to give it a try with a heat mat this Jump Start Windowsill heat mat and kit contains everything to get you going. Most plants germinate best in a temperature range of 65°F to 75°F. During cool weather that means a heating mat will be required.

Feeling more confident? Don’t let seed starting scare you this year!

  Comments (5)


Hi - I got a 200 cell speedling tray recently.  If one puts the tray on top of the frig how do they get the light they need?  Is light more important than heat here?  I spoke with a friend who used a similar ‘air prune’ system - she said she watered her tray by placing it in a water-containing tray so the plants got water from the bottom up.  Would that be ok with the speedlings or must I mist from above?  Thanks

Posted by oxmyx1 on May. 20, 2011 at 7:24:58 PM

oxmyx1, The warmth on top of the refrigerator is the important part of sprouting. As soon as you see the sprout, move it to a location with brighter light. With speedling trays it is easiest to mist them from above. They are somewhat buoyant and that makes watering from below potentially tricky.

Posted by on Feb. 14, 2012 at 4:57:03 PM


How many seeds can you plant in the pellets in the windowsill kit? Is it 1/pellet?

Posted by Shannon Little on Mar. 08, 2014 at 12:14:17 PM


You need some source of disease prevention or you will lose newly germinating seedlings.

Posted by Dr. R. on Mar. 08, 2014 at 12:27:06 PM

Hello Shannon,
It depends on the species. Plants like peppers and tomatoes with high germination plant two; something like basil with a low germination rate plant a couple more. If they both germinate thin to the strongest seedling.

Posted by on Mar. 10, 2014 at 10:11:47 AM

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