Starting Your Seeds

Two styrofoam shallow seeding trays with soil and labels in each cell
Starting My Seeds

When to Start

I do not have a greenhouse and never have.  I don’t like to start seeds indoors.  I do not want to invest in the lighting and the space, and I don’t want to deal with the mess. 

And I especially don’t want to end up with spindly, leggy seedlings. This makes weak plants.

So I prefer to wait until the frost risk is lower and the days are getting pretty warm.  Which is in April where I am in the Sierra foothills in Northern California. 

I use seeding trays (See Containers below) that make it easy to move a lot of seedlings to shelter quickly in case of a late snow or frost.  And when days are moderately warm with lots of sunshine my seeds germinate and grow fast. 

I feel that starting my seeds outdoors gives sturdier plants.  Legginess is avoided and air circulation is perfect so I never deal with damping off or other fungus problems.

The only plants that this isn’t good for is tomatoes, peppers, and eggplants.  But there are so many growers that use greenhouses and sell wonderful varieties, I just buy these.  A few of my favorites, though, are usually unavailable, so I do start these late, and harvest late, and enjoy them and can or dry them late.  Like August.  That’s fine with me.

For my flowers, they’re still planted out at a good time.  With lots to harvest.

Tiny seedling just emerging with arrow pointing to it
Tiny seedling just emerging

Seed Starting Medium

For starting seeds in a container you want a mix that is sterile and well-draining.  Sterile mix will be less likely to have damping-off fungus.  Damping-off fungus attacks new sprouts and kills them.  You’ll know it by the way the seedlings emerge then collapse and rot.

Seed starting mixes are available in packages or you can make your own, which is what I do.  When you use Speedling trays, you need only a little. More on those in a bit.  This is only for starting seeds and growing to transplant stage.

For my mix I choose to use coconut coir made from coconut husks.  I feel this is much more sustainable than peat moss.  Disturbing and mining the peat  bogs has pretty big environmental consequences.  So I choose the coconut coir as a better, more sustainable alternative.  Even though it is not perfect, environmentally.  Though it is great functionally.  You can read more about the issues and choices in this article by Adrian Higgins from The Washington Post.

The coconut coir comes in compressed blocks.  You can hydrate the whole thing or, if you can manage, cut off a chunk to hydrate a little at a time.  But it’s difficult!  But if you hydrate extra you can store it.  One block, once hydrated will fill a wheelbarrow.   

What I do is put the whole block into a wheelbarrow or a tub, put quite a bit of water into it (it soaks up a lot!) , let it sit for a few hours, then break it apart until it’s uniform and lump-free.   I take out what I need and let the rest sit in the sun to dry then store it in a bin.

The coir, like peat, is a medium that keeps air in the mix because of its porosity.  The next ingredient is one to hold water.  That can be done with either perlite or vermiculite.  The perlite should be a fine grade, not coarse.  It holds the water all around its porous surface area.  Vermiculite is heat expanded mica which holds water between its layers.  It  can contain asbestos. 

The next step is filling the containers. I fill the containers with moist soil mix, not wet or dry.


Clean Them

Whatever containers you use they must be clean to be free of pathogens. I use to sterilize mine by submerging them is a bleach solution. The recommendation is about a 10% bleach solution. An easy way to achieve that is by adding enough bleach to your tub of water so that you can smell it, but not too strongly. You may need to weigh down the containers with a brick or rock to submerge them. Leave them for a bit to soak. Then rinse.

I now skip this step. I use Speedling trays (more on that in a bit). To clean them I use a jet spray on my hose-end nozzle and spray water with force into each cell and all around the tray. Then I let them dry in the sun for some sterilization. I haven’t had any problems in the years I’ve done this, but if I did I would give everything a bleach treatment.

Speedling Transplant Trays

Photo of seeded Speedling tray
Seeded Speedling Trays

The most efficient way to start seeds is in cell trays. The ones I use are the Speedling Transplant Trays. They are made of styrofoam, making them very light and easy to carry around and giving some insulation in case it gets cold.

The trays are approximately 26″ x 13″ and come in several cell sizes. I use the trays with 200 cells and 128 cells, the 200’s being good for smaller seeds. Any cell size is good. But I use the larger sizes cells that are 72 calls per tray for large seed like squash and gourds.

Many people use flats, 6-packs, and other pots for their seeds. And those are good. But the Speedling trays are very durable and last for many years. Another  benefit is their cone-shaped cells which prevents the circling of roots.

These trays pack in a lot of seedlings for little space, soil, and ease of movement. The ease of movement is real useful in case of a late frost or other inclement weather event where you can move them out of harm’s way. I move mine to the shade if I’m going to be away for a 24 hr. period, watering them before I leave and after I get back and I don’t have problems.

Plus, I can pack hundreds of seedlings onto a 2 ft. x 6 ft. table. For a home flower grower, you may only need a 200 or a 128 cell tray. This can include tomatoes, lettuce, and other vegetables and herbs.

Speedling trays are inexpensive and a very worthwhile investment

Filling your containers

When you fill your containers you want to be sure there are no large air pockets. That’s fairly straight-forward if you are using traditional pots and flats, just filling them and lightly tamping with your fingers.

For the Speedling trays I spread the moist, not soaking. soil over the cells, smooth it out, and then use two fingers to tamp two cells at a time running down all the rows. Then add more soil to the divots.

Next I water the containers to settle the soil. Them let them dry a little before seeding.

Planting your seeds

Plant a seed as deep as it is wide. It’s a good rule of thumb to go by. That said, I truly believe that’s a fair amount of wiggle room. So if the seed is 1/4 inch wide, plant it 1/4 inch deep. But don’t stress over accuracy, just come close.

In the cells I use, I hold a seed between my forefinger and thumb, use the middle finger to push the soil away to a depth I want, place a seed or two or three, then cover it with the soil. This way one finger gets muddy while the other two stay dry to manipulate the seeds. Detailed, yes, but I can get a lot seeded quickly this way. You’ll figure out your best way, too.

Some seeds require light to germinate. But if I put the seeds at the surface they could get splashed out when I water them. So I put a few seeds into the cell and push them in a bit and then push a little soil over them. So they’re covered but some light still gets to them.

Some seeds require chilling before germination. To do this you need to mix the seeds with a slightly damp medium, like coir, sand, or peat. Put them into a zip-loc bag and put them in the refrigerator for 30 days, or whatever the seed instructions say. Then take them out and plant…

… but I never do this. It doesn’t lend well to finding the seeds easily and putting them into my Speedling cells. So I go right ahead and plant those seeds right into my cells with everything else. I have never been disappointed! I think the reason is that I start my seeds in trays outdoors in the very early spring where they are subject to very cool nights. I usually don’t let them freeze, but it happens sometimes.

Chilling is supposed to increase germination, but may not be entirely necessary. At least for the types of plants I plant.

I read a publication from UC Davis long ago, that when tomato seedlings were subjected to just above freezing nighttime temperatures, they fared better later when freezing temperatures arrived. So I think there’s something to using normal (but not freezing) ambient outdoor air.

How many seeds to plant?

I always plant more than I need. Sometimes there’s a low germination rate. Low germination can be inherent to the seed, the variety, from poor storage, or from older seed. Or even from lack of chilling. (See above on that.) To compensate, planting extra is the most time and expense efficient way to be sure you get what you want to grow. And…well…those Speedling trays do make it simple and space efficient!

Label them

Don’t forget to label your seeds. Trust me, you won’t remember what’s what. My system is to go from left to right and from bottom to top and put the label in the last cell of that variety.

I include the date-it’s a good reference for the next year. And, well, it serves as my record keeping.

I use labels that are made of recycled plastic.

And my implement of choice is a simple #2 pencil. It’s easiest to use and doesn’t fade from the sun.


Water your newly planted seeds. Use a very fine spray. Fogg-It-Nozzles* are great at being gentle. I use a Haws watering can, but they’re hard to find these days. It’s very gentle. I only use it to water my Speedling trays, especially with freshly planted and emerging seedlings.

Keep soil moist. After germination, allow a little drying between waterings. You do need to visit the seeds 2-3 times a day to check for water needs. If you can’t do this, keep the seedlings in more shade to keep the soil from drying out too quickly. And, of course, it all depends on the weather.

Light & Air

Give your seeds plenty of light and air circulation. As I said above, I put mine out where they get direct sunlight for  st least six hours a day. This requires regular checking for water needs. If you can’t check them often, they can be put into more shade. They’ll take longer to germinate. You may set up a sprinkler on a timer to spray them, too.

Being in the outside air gives good air circulation which is so good for preventing fungal diseases, like damping-off. Damping-off is a fungus that can rear its head when conditions are damp (or wet), cool, and with low air circulation, or from unclean containers.

And being in the sun helps the seedlings grow strong stems. You don’t want leggy stems, they won’t be strong.


Since a seed comes equipped with the nutrients it needs to germinate, no fertilizing is needed until the first true leaves are growing. Th e soil medium has no nutrients, so you need to start supplying some.

It’s never the perfect scenario with all the seedlings emerging at the same time.  So you need to make the call. When enough seeds are showing their first true leaves, start watering with a dilute balanced organic liquid fertilizer with minerals. I stress dilute, because too much fertilizer can burn the delicate seedlings.

Follow the directions for seedlings on the package. I use Bio-Link.

Related Reading:

Little seedlings in Speedling trays out on the soil ready to get planted.

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