Seed Starting 101

It’s time to start your seeds! There are so many different methods out there and competing advice on all of it.  Over the years, I’ve incorporated, what I feel, to be the optimum steps to follow for successful germination and healthy plants. Below are all of the steps I follow.  These things are also covered in a new video; here is that link.

Step 1:

Choosing Seeds – Do your due diligence and choose varieties that grow well in your region. There are so many sources out there from just knowing your growing zone, reading regional gardening books and magazines, to talking to local gardeners/nurseries all the way up to your county AG extension agency/website. Local resources also suggest varieties that are resistant to plant diseases and viruses that are most common in your region.  This step will save you time and heartache.

Step 2:

Storing Seeds – Store your seeds effectively.  Proper seed storage conditions are below 40°F with less than 10% humidity, tucked inside airtight containers in a dark environment.  Some keep theirs in the freezer.  I do not; I store my seeds in an extra refrigerator we have in our basement.

Step 3:

Prepping Seeds – Seeds need light, water, and oxygen to germinate. Most gardeners remember the light and water part of the germination equation, but overlook the seed’s need for oxygen. Old seeds, seeds with particularly hard coats, or those vegetable seeds, like peppers and eggplant, that are particularly harder to germinate are more likely to come up short on the ability to absorb oxygen. This negatively impacts germination rates and your garden success.

There are two methods I use to assist in breaking down the seed coat thus allowing the seed to take in more oxygen:

 A) Soaking Seeds

I soak all my seeds (with the exceptions of the super tiny ones like lettuce, carrots, onions, and radishes,) prior to germinating them in paper towels or directly sowing into potting mix. The solution I use is 1 ounce of 3% Hydrogen Peroxide to 1 pint of warm water (2T/2C).  I use room temperature to lukewarm water.  The seeds are soaked in a water tight container for 4-24 hours.  The longer soaking is for the seeds with very hard outer shells. TIP:  After 15 minutes, the seeds that sink are still viable; if the float, they most likely will not sprout.

The Hydrogen Peroxide serves two purposes:

1)    Recent scientific studies have shown it increases the germination rate by breaking down the seed coat, thus allowing the seed to take in more oxygen.

2)    It will kill off any bacteria that your seeds may have picked up.

B) Scarifying Seeds Prior to Soaking

Scarifying or seed abrading allows moisture to enter a seed, which in turn “wakes up” the dormant embryo and gets it growing. Even though the hydrogen peroxide is a way of chemically scarifying seeds, I additionally, manually scarify seeds with hard coatings prior to soaking.  Examples of seeds in this category are – squashes, melons, cucumbers, morning glories, moonvine, and nasturtiums.

There are several ways to scarify seeds:

1)     Use moderate pressure and rub seeds with coarse sandpaper for 20 seconds or so.

2)    A nail file can also be used to make a nick on the outer seed coat, preferably opposite the hypocotyl or “eye” which is where the new shoot will emerge from.

3)    A small pair of nail clippers can also be used very carefully to nick the hard shell, again avoiding the “eye” or cutting too deeply and damaging the embryo.  This is my method of choice as I find it easier to hold the seed.

Luckily, most vegetable seeds are soft and don’t need scarifying manually.

 

Step 4:

Pre-Sprouting Seeds – I like to be assured of germination by pre-sprouting the soaked seeds using the paper towel method.  The only exceptions are those that prefer to be direct sown and tomatoes. The reason for the tomatoes is that I just never have an issue with germination and I plant soooo many, it’s just too time consuming for me.

Seeds can be placed into three categories in terms of transplants and their level of toleration when it comes to their roots being disturbed.  I’ll show you that chart in the next step when it comes to actually planting. For now, here are the steps to pre-sprouting:

1. Dampen a half-sheet of paper towel in water. Don’t saturate. You just want it damp, not drippy.
2. Spread out soaked seeds far enough apart to not touch and get intertwined while sprouting.
3. Gently fold and place in a ziplock bag.
4. Label the bag.
5. Use the soil temperature chart below to decide where to place the bag. All seeds need warmth to germinate, you can place the bag on top of the refrigerator (which is typically warm from the motor,) or preferably a garden heat mat. If you’re really fancy there are mats with built-in temp controls, but  they make separate temperature controllers that you plug one or multiple mats into. Currently, I don’t have temp controllers.  It’s on this year’s wish list.
6. Check your seeds every day. Don’t let the paper towel/seeds dry out. You can use a sprayer to gently mist inside the bag.  Germination varies for different seeds, but generally speaking, most will germinate within a week.
7. Once you see sprouts, handle them carefully. I use a pair of sterilized tweezers to pick the seed up and drop in the planting hole. I sterilize the tweezers by using isopropyl alcohol and rinsing with water.

 

Step 5:

Planting the Seeds – I will state right up front, that I never…never, ever, ever use peat pots! Don’t buy the bogus claim that they disintegrate once planted.  They do not! It takes years for that to happen. Additionally, peat pots will dry out extremely rapidly.  They also tend to grow mold where the bottoms sit when watered. Okay, I’ve said my peace about those overpriced, over-advertised peat pot excuses for a good pot. LOL! Now, to move on!

For those seeds I intend to direct sow, I simply soak the seeds the day before planting. I always check my outside soil temps of containers and the weather forecast for several days prior to.  For the rest I intend to grow as transplants, I have a couple of guidelines I follow to determine container size and timing.  The timing is pretty easy as most seed packages tell you how many weeks prior to your “last frost date” in the spring and “first frost date” in the fall for your region.

I also plant 10-20% more than I need, especially with older seeds. Pre-sprouting/germination test can predict viability.  It can’t truly predict vigor – how well a seedling will grow in terms of health, strength, uniformity, and root system, not to mention its production of flowers and fruits. A seedling with compromised vigor may have a missing cotyledon, look stunted or scrawny, or seem overall slower to develop than seedlings from fresher seeds.  Sometimes older seeds just don’t have it in them to go all the way to seed again.  A will to germinate does not equal an ability to thrive.

For determining container size, I look at whether the transplants fall into the easy or fussy category in terms of tolerating their roots being disturbed as I mentioned earlier.

For the easy ones, I plant the seeds in 3” net cups in a quality potting mix.  I usually plant two seeds/cup to ensure I get one really good one.  Normally, they are both great and after the first couple of sets of “true leaves” develop, I transplant one of the two into another 3” net cup.  (I give extra transplants away to friends every year.)

Most all in this list will stay in those cups until they are ready to be transplanted in their final home outside, with the exception of the main ones that outgrow their pots and benefit from being successively planted deeper each time, specifically tomatoes, peppers, and eggplants. You will be surprised, though, just how long nearly all can stay in those net cups!

For the fussy ones, I plant two seeds in 4” net cups.  After two sets of true leaves develop, I use a sharp, sterile pair of scissors and cut the stem of the weaker of the two. Depending on the vegetable, most of the fussy category are planted approximately 4 weeks before they are to be transplanted to their final home.

Below is the chart I compiled of the three categories of transplants.

Step 6:

Planting Process – Why use net cups? As mentioned above, plants need oxygen in addition to light and water. The net cups provide that with the series of slanted openings in the sides.  Secondly, the net cups allow for air pruning the roots.  Have you ever bought plants in plastic containers and upon removal noticed a network of roots all bundled tightly growing in a circular fashion the shape of the plastic container? Those are very root bound! They have nowhere to go and grow and you can be pretty assured they have used up all of the nutrients in the growing medium.  With an air pruning container like net cups or grow bags, the roots don’t do that.  As they grow toward the outer edge the air naturally prunes them and sends a message to the plant to grow roots back the other direction.  You get an AMAZING network of healthy roots all growing downward.

Here are the steps I follow for actually planting the sprouted seed:

1.  Clean all net cups, trays, plastic domes with a diluted solution of Clorox and water, a 1:10 ratio. Rinse with water.
2.  Fill the net cup with potting mix and tap down a bit to ensure it is full.  I use Larry’s recipe mix for this too!
3.  Pick up the net cup and “feel” the weight of it with just the dampened potting mix in it. This is the weight when you will need to   add water in the days going forward.
4.  Pour 2.5-3 Tablespoons of warm water in the top. Pick up the net cup and “feel” this weight understanding this is the weight you want when properly watered.
5.  Use a tool to open a hole in the mix to the depth the particular seed requires. You’ll find that info on the back of the seed package.  Optional tools: finger, pencil, end of a plastic spoon, etc.  I actually have a small piece of bamboo that I use.  I made marks on the bamboo stick at ¼, ½, and 1 inch as a guide.

   

   2.5-3 T Warm Water

   

   Measure Marks

   

   Baby Sprout

   

   Handle Gently and Plant

   

   Use Cinnamon

   

   Protection from Dampening Off

   
   
6.  Using tweezers, carefully pick up your little baby sprouted seed and drop in the hole with the sprout (the developing root) facing downward.
7.  Use your fingers to push potting mix over the hole.
8.  Give it one or two single sprays of warm water from a spray bottle.
9.  Sprinkle cinnamon over the whole top. (Cinnamon helps prevent dampening off which is a disease of seedlings that occurs in excessively damp conditions.  In particular, it is the collapse and death of young seedlings as a result of a fungal infection.) I never have problems with dampening off if I always remember to do this step.
10.  Set your net cups in a hole-less tray and cover with either a plastic dome or saran wrap. This creates a mini-greenhouse effect for your babies. They like that!
11.  Place on a heat mat. (See info below on temps after seedlings sprout through the potting mix.)
12.  Check the seedlings daily for growth and need for water.
13.  Once the majority of your seedlings in the tray emerge. Remove the plastic dome and lower your grow lights to ONE INCH above the highest one. Grow lights are essential! I will go over that topic in the next section.
14.  I have a small oscillating table fan that I set up and run 24 hours/day on the baby seedlings. This helps develop sturdy stems and additionally helps with not getting any dampening off.  You want the top of the mix to be relatively dry which is another reason bottom watering is key.
15. When your seedlings need water, pour ¼” of room temp water in the bottom of the tray. Check after ten minutes or so; if all of the water has not been absorbed, you need to remove the excess.  It’s a pain to remove all of the cups just to dump the water from the tray, so I have an extra turkey baster devoted just for this purpose.
16.  Raise your lights as the plants grow continuing to keep them ONE INCH above. If you have leggy stems…your light is higher than one inch and/or the heat mat is too high!

Temps After Seedlings Sprout Through the Potting Mix

Germination instructions for many seeds recommend growing on the seedlings at a cooler temperature once they have sprouted. Therefore, many of your seedlings won’t need to stay on heat mats once sprouted.  I’ve found that peppers, eggplant, and basil benefit from a couple of additional weeks on a seedling heat mat.  At that point they do just fine in 65-70 degree F. I definitely remove tomato seedlings from the heat after they sprout or they can become very leggy and can spur rapid, lanky, weak growth or encourage fungal diseases at the soil level.

The chart below is just a basic guide.  For most fast-growing annuals, a good initial range at which to operate an indoor garden is 70-80 degrees F. Remember, the grow lights can give off heat, too, depending on the type you use.

Step 7:

Growing Healthy Transplants – Well, I’ve covered water, oxygen, and touched on light, but let’s get to the nitty gritty on the latter, first.  If you’ve ever priced grow light set-ups, you soon discover that they are EXPENSIVE.  Sure, they are nice, and you can buy them with a terrific stand which raises and lowers the light for adjusting the height, BUT… unless you have unlimited funds, you can make your own for about a third of the cost.  Tip: I save the box the light came in for easy disassembly and storage after the seed starting is over for the season.

Here is the link to the video that demonstrates setting up a grow light.

Grow Lights – Here is what I buy:

1. A 4’ standard shop light. I used to purchase T-12’s, but those are hard to find now. T-8’s work just fine.  They cost around $12.
2. A ten foot stick of 1” PVC. $4
3. 2 elbows and 2 T fittings for the PVC. $3.50
4. A pack of 2 florescent bulbs with 1900 lumens or greater. I pick the ones that say sunlight in terms of brightness. $10.
5. Extra chain – just the small stuff is fine. $3
6. Small S hooks – $2

 

Grow Lights – Here are the measurements I cut:

Using a hacksaw, I cut the following lengths of PVC:

1)    One piece – 52”-56” depending on the length of your table you are using. (I have 6 foot folding tables, so I cut mine at 56” to keep them from falling off   the edges, especially if Lucy brain accidentally bumps them.  She has done that!)

2)    Two pieces – 20” long.  These serve as the legs. (If you cut your main piece 52,” you can cut these at 22” which will give you a little more height for the growing plants.)

3)    4 pieces – 6” long.  These serve as the leg braces.

Grow Lights – Here is how I assemble it:

1) Place the elbows at the ends of your long piece. Insert the 20”-22” legs into the other ends of the elbows. Attach the T’s at the end of the legs. Insert four 6” pieces into each end of the T’s.  Voila! You made a stand!

2)Assemble your light fixture according to the directions. Use the chain that comes with the light along with the additional chain you bought to make them longer. I use the S hooks to add the chain.

3) Rope the chain over the top long PVC piece and use S hooks to connect.

4) Place trays of seedlings, long end to end, under the light.

5) Adjust the light height to ONE INCH above the tallest seedling.

Your seedlings need between 16-18 hours of light a day, and 6-8 hours of darkness.  This is most easily accomplished using a programmable timer. The last picture shows a double light arrangement to utilize all of the table depth accommodating turning the tray short side out and/or using larger trays. The video demonstrates exactly how to put this together.

Fertilizer – Since I now start my seeds directly in a potting mix that contains compost, I don’t need to add fertilizer throughout the growing period.  The only time I add anything, is if I am potting them up to a bigger pot and also at transplant time when you initially top water it in.  In both cases, I add compost tea that I brew.  There are many methods for making compost tea.  I’m not “in” to all the science-y stuff, nor do I have the time.  So, I use a pre-packaged product called Boogie Brew. Their website is www.boogiebrew.com. It truly is a balanced and fantastic product.  They sell a whole kit and have easy-to-follow videos of how to brew it.  They additionally have several other products that I love.  I buy my worm castings from them that is an amendment I add to Larry’s recipe mix in my buckets and grow bags and a soluble mycorrhizae that I use in the bottom of the hole when I am potting up to a larger pot or at transplant time with those that have remained in the net cups all during initial growing. Not a “have too” step, but this is an article explaining just what I do to start and grow seedlings.

Here is the deal though…IF you have chosen to start your seeds in the traditional way using sterile seed starting mix, I highly recommend that you fertilize your babies once the second set of true leaves appear with a quarter strength diluted solution of fish emulsion. Continue that every week to ten days until you pot up using regular potting mix or until you transplant outdoors.  Remember to bottom water in the tray.

Seed starting mix has zero compost in it.  It is simply a mix of peat, perlite, and vermiculite. When I first began starting seeds, I did all of those recommended steps: seed starting mix in those teeny tiny cell trays, then graduated them in bigger containers using potting mix that had compost in it. ETC., ETC.

A few years later it HIT me!!! I understood the science behind the sterile seed starting mix, but what about the seeds you direct sow out in the fertile soil of a garden that has compost and all of those goody amendments there? Why don’t the experts recommend creating a hole or trough filled with sterile mix for those seeds? My conclusion, however suspicious it may sound, was that pricey seed starting mix is a money maker. (Insert here – even when I did all of those traditional steps, I still made my own mixes saving a good bit of money.) Sooooo, now you have the skinny on why I started bypassing all of that and just use straight up quality potting mix! It works! Give it a try and save a bunch of your valuable time.

I think that wraps it up for how I start seeds.  As the time draws near to harden-off and transplant outside, I will write another article to go along with videos of the process that will be posted on our YouTube channel.  Hope you found this helpful!  If you have any tips to add, please do so in the comment section! I love to learn new things!!! Happy Gardening y’all!

“I’d rather have home grown food on my table than diamonds around my neck.”

– me