Starting your seeds indoors

After a long winter there’s nothing more hopeful than pushing seeds into fresh potting mix.

For many years I have been starting my seeds indoors under lights before transitioning them to an outdoor unheated hoophouse.

I want to share with you how easy seed starting can be!

I’ll start by outlining what you’ll need to get started:

• Pots and domes

• Seeds

• Potting mix or growing medium

• Lights

• Heat mats

• Shelves

Now I’ll walk you through each of the above items in more detail…

Pots and Domes

I use 11x21 inch trays and fill them with soil blocks. Interested in soil blocking? Read more HERE!

You can also use 4 pack or 6 pack plastic containers. Or plant straight into 3-4” pots. You can find all these options at your local garden store.

So should you choose a larger pot or smaller pot? If you plant into larger containers you won’t have to worry about transplanting later when your plants are getting big. But if you’re growing a lot of plants you’ll get more plants in less space if you use the 4 or 6 packs.

Also invest in a few plastic domes! These will help keep the humidity perfect for seed germination.

Seeds

Ready to order seeds? Go to my blog on where to order seeds HERE. It’ll help you get off to a great start.

Potting Mix

There are a few products that I really like. If you’re in Anchorage, you can find them at Southside Garden Supply or Alaska Mill and Feed.

1) Pro-mix MP Mycorrhizae Organik. This is a great all-round potting mix and it’s organic! I’m using this for all my seed starting needs this year. It is also working great for soil blocking! Find this in cubes at Grow Generation.

2) Fishy Peat or Alaska Earth - made in Alaska! I’ve had success with both products. They are not organic but are made with wholesome natural ingredients. Both can be found at Alaska Mill and Feed.

3) Fox Farm Light Warrior or Ocean Forest- this company has a variety of potting mixes and seed starting mixes. They use natural products and they work great! Grow Generation and Alaska Mill and Feed carry these.

Note, that if you’re growing a lot of starts, buying a cube will be more cost effective than buying individual bags. Ask your local garden store if they offer these products in cubes!

Lights

To be honest, I tend to be opportunistic when it comes to lighting. I look for free stuff and cheap stuff. And what’s great is that they’ve all worked just fine. So here’s what I’ve used: LED shop lights from Costco, florescent shop lights as found in any hardware store, grow-specific LED lights. All these will do the job! I say buy whatever fits your budget best.

The most important steps when it comes to lighting is 1) to keep the lights just a few inches from the plant to prevent “leggyness” and 2) to give your plants 16 hours of light (an inexpensive outlet timer works great for making this happen).

Heat Mats and Thermostats

For the BEST germination, invest in a a seed starting heat mat AND thermostat made specifically for this. This will cost you around $70.00-$80.00 If you can’t afford this your first season, don’t sweat! But even soil heat at around 75-80 degrees will give you the best seedling germination (for most plants).

Soil temperatures are roughly 10 degrees cooler than ambient room temperature, so often your soil may be cooler than you think without a heat heat mat.

Shelves

I use simple metal wire shelving so I can stack my seedlings. But get creative here! You’ll just need a place to hang the lights and a place underneath to set your trays.

NOW you’re READY TO PLANT!

1) Fill your pots with damp soil.

2) Put 1-2 seeds on top. Your seed packet will give you a germination rate for each seed. If its less than 80% put 2 seeds in each pot.

3) Lightly cover with soil. Just barely cover as light aids the germination of most flower seeds. I like to cover just so there is a bit of soil contact on top of seed.

4) Cover with a plastic dome and place under lights and on heat mats.

5) Keep seeds damp but not overwatered. Once seeds germinate I vent the domes by making sure there’s a bit of airflow between the tray and the dome. You can also take the dome off if it’s getting too moist in there.

Happy planting out there!

Starting Seeds with Soil Blocks

New Methods

A few years ago I was inspired to change up my seed starting system to include soil blocking. I now use it exclusively.

If you’re not sure what soil blocking is, I’ll walk you through the whole process! Soil blocking requires taking a wet growing medium and using a little blocking press to create perfect stand alone squares in which to sow a seed or transplant.

I invested in a 3/4” blocker for germinating slow growers and tiny seeds and a 2” blocker for transplanting into or sowing larger or quick growing seeds. These are available from Johnny’s Seeds (my favorite online planting/growing store).

After lots of experimenting with growing medium (I’ve mixed my own, I’ve purchased all sorts of seed starting mix) I’ve settled on Pro-mix MP Mycorrhizae Organik. I purchase large bales at Southside Garden Supply each spring.

If you’re interested in trying to mix your own starting mix, here’s a recipe from Lisa Mason Ziegler. She’s author of Cool Flowers (a great book about maximizing your cool shoulder seasons for planting early in the spring or late in the fall - I’m still trying to perfect this method in a snowy climate, and honestly still sort of flailing):

Recipe

16 C sifted peat or coco fiber (I used our local Fishy Peat mix available at Mill and Feed) 

4 C of sifted compost (I used Susitna Organics humidified compost)

1/4 C greensand (available at Southside Garden Supply - let me put a plug in for this awesome local shop. Thanks to the marijuana industry, this place is loaded with great stuff for the urban farm or garden set-up)

1/4 rock phosphate (Mill and Feed or Southside Garden Supply)

6-7 C water

How To

Mix all ingredients well in a large tote or bin. One batch makes around 600 mini blocks.

If you’re using Pro-mix MP Mycorrhizae Organik or another pre-made mix, just mix a set amount of soil in a tub and add water until it’s a very wet mud.

Once your planting medium is all mixed grab your blocker, dip in a dish of water (aids in releasing blocks), firmly press your blocker down into soil medium a few times to really pack it in, scrape off excess, and while holding just above the bottom of your seeding tray depress the plunger until blocks release.

It takes a few tries to get the hang of it! Seeds can then be planted in the little depression left my the blocking pin.

Get creative about what you use for trays. I use regular seedling tray bottoms with no holes. I reuse these every year for 3-5 years! Folks also use lunch trays, plates, left over styrafoam trays, yogurt lids, etc.

Growing on

To water, less is more. Although you don’t want to desiccate your precious seedlings it’s easy to over water and get disastrous results (like damping off). Be sure to water from the bottom to preserve the delicate soil block structure. They wick up water like crazy. 

Once the 3/4” blocks are ready to transplant, plant directly outdoors or up-pot into a 2” or 4” block. I up-block into a 2” block for most of my starts.

The larger seed blockers come with a different blocking pin that creates a square indent that perfectly fits a 3/4” block.

Now go grow some epic plants!