Seed Starting 101

Growing plants from seed is the most economical way to garden. Generally, I prefer to direct-sow seed into the soil where they will live out their life.  However, there are a number of plants that do better when
started from seed indoors, allowed to grow for a month or so, and then transplanted into the garden.

Since there is a small greenhouse on our property, it gets used for this purpose.  Every greenhouse is different, and after 7 years of using ours, I know what works and what doesn't with our quirky little hothouse.  So, in this post I'm going to explain how I start seed with my existing set-up and also walk through how I'd start seed in my house if that was my only option.  Starting seed is very simple...you just need heat and moisture. However, maintaining the correct moisture level and the nailing the right temperatures to germinate your seed can be frustrating.  So, here are my 5 steps to grow plants from seed:

Step 1: Choose Seed
Again, I prefer to direct-sow seed into the garden as often as possible. However, I generally start tomatoes, peppers, and basil in the greenhouse, mainly because they are not cold-hardy at all.  This way, they can go into the ground in late April with a two-month headstart vs. direct sow in the garden.  I want my first ripe tomatoes to arrive in June, not August.  Our 2017 tomatoes will include Black Cherry, Yellow Pear Cherry, Peacevine Cherry, Mountain Princess, San Marzano, Black Krim, Amy's Apricot, Matt's Wild Cherry, Beefsteak, Delicious, Rutgers, Brandywine, Cherokee Purple, Mortgage Lifters, and a Givler Garden-bred varietal that I call Yellow Paste.  Peppers include Habanero, Chocolate Habanero, and Kung Pao.  I've started Sweet Basil, Genovese Basil, and Dark Opal Basil.  This year I'm also testing indoor germination on a type of Leaf Celery and Late Flat Dutch Cabbage.

The following seeds will NOT be started in the greenhouse, but instead will be sowed into the garden in the next 6 weeks: peas, fava beans, spinach, lettuce, radishes, and carrots.  I buy onion and potato sets and will plant those into the garden as well.  They're not seeds, but sets are cheap.  I actually don't know anyone who grows onions or potatoes directly from seed.

Step 2: Set Up Trays
After years of trying a multitude of seed-starting mediums, I now swear by coir and Jiffy brand Pro-Hex Seed Starting Trays.  Coir is the outer husk of a coconut.  It is chopped up fine, compressed into bricks, and sold as potting soil.  For seed starting, you need a very fine substrate, since the more surface area of wet soil that touches the seed, the higher your chance for germination.  Coir fits the bill. It's also compact, dust-free, and retains water like a sponge.  You can find coir bricks online for about $6 a brick. I fill a 5-gallon bucket halfway full, toss in a brick of coir, wait about 30 minutes, and my potting medium is ready to rock.  I grab a big wet handful of coir and smear it into the cells of the Pro-Hex Tray.  This is not a commercial - I get nothing from Jiffy, and I'm sure they have no idea that my blog exists.  That said, the Pro-Hex trays need less potting soil than other trays, have a nice flat top that makes them easy to fill, and have a design that makes it easy to pop out seedlings for transplanting. Once I've packed the trays with coir, I make a small indentation in the top of each cell.

Step 3: Sow Seeds
Seeds are cheap, and I don't mind thinning seedlings later as needed, so I over-plant seeds in each cell to guarantee that every cell winds up with a plant.  If it is seed packed for this year, then I put two seeds in each cell. If it is older seed or seed that I saved myself from last year's garden, then I put 4 seeds in each cell.  I usually just use my fingers to sprinkle seed carefully into each indentation.  I use the same seed type in each lengthwise column (12 cells), put a little plastic marker with the plant variety in the first cell, and then flick a bit of coir on top of the planted seeds...and I'm done.  Now, if I am starting these seeds in my house, I would then place the clear plastic cover on the Pro-Hex tray and put the tray on a table next to a window that gets good sun all day.  Since I'm doing this in my greenhouse, I don't cover the trays...I've learned that the "double greenhouse" effect can literally cook my seeds and seedlings.

Step 4: Keep 'Em Warm and Wait
Since I started with sopping wet coir, these trays won't need much water...none at all if they are covered.  However, temperatures in my greenhouse fluctuate and I need a few sunny days in a row to guarantee germination.  It is also crucial that they don't get too cold at night.  Our greenhouse has zero insulation, so there is a electric heater in the greenhouse that fires on when it gets around 45 degrees.  If the coir ever gets dry, I re-water the tray, but only with water that is room temperature or warmer.  I keep a couple buckets of water in the greenhouse so that they stay the same temperature as the seed trays.

Step 5: Sprouts!
If you've used viable seed, and kept them wet and warm, you will have success!  Seeds will sprout into seedlings, and they will grow into plants that can be put into your garden for a fraction of the cost of buying live plants from a retailer.  Wal-Mart sells seedlings at 6 plants for about $3.  That's 50 cents a plant.  On the other hand, you can spend $5 on a tray, $6 on coir (or less, since a brick of coir is enough to fill at least 3 trays), and $2 on a packet of seed and wind up with 72 seedlings for $13. That's 18 cents a plant.  Reuse the tray the next year, and you're at 11 cents a plant.

So, that's how I start seed.  It's a fun and economical way to grow your own garden transplants.