How Not to Kill Your Seedlings

I've just wrapped up my spring seed share!  I had an abundance of seeds (as I always do - I may have a bit of a problem) and normally at this time of year, I run a seed starting party out of my house to share these seeds at a minimal cost.  But, COVID.  So instead, I created a Google Form where friends could order a personalized collection of seeds from my stash.  Because these come without seed packets, this post is an effort to simplify seed starting with some universal guidelines.

The only people who haven't killed seedlings before are the people who haven't tried to grow them in the first place.  I'm serious...it's like a right of passage.  It makes sense, though, when you think about it.  What we're doing when we start seeds indoors is outsmart nature - to extend the growing season by forcing seed germination in unnatural conditions, before the seed is naturally ready.  As such, they require a particular set of conditions in order to survive and thrive.  So here it is - my short list on how NOT to kill your seedlings.

1. Don't plant ALL of your seeds indoors.

Just because most seeds CAN be started indoors doesn't mean they SHOULD be.  Likewise, if you plant ALL of them outdoors after the May long weekend, they'll probably still grow.  So how do you know what to plant where and when?  Here's what I usually do:

Do plant indoors: compact lettuces like iceburg or romaine, as well as tomatoes, peppers, celery, kale, herbs and most edible flowers.

Plant directly in the ground after May 24: all root vegetables, beans and peas (their shallow roots make them hard to transplant) and nasturtiums.

Doesn't matter: squash, cucumber, chard, and melons.  

If you're still not sure, do a little experiment.  If you have enough seeds, when you go to transplant them outside, plant another seed right beside them.  Watch them both and see which one does better.  Chances are, after a week or two, the direct-planted seed will have caught up to your seedling.

2. Don't plant them too deep or too shallow.  

This one's actually pretty easy to avoid.  You can use the seed packet instructions for this, but I don't do that anymore because there's a good rule of thumb.  Plant your seeds at a depth of about 3x the size of the seed.  For tiny seeds, that means they're going to be barely below the surface.  For larger seeds like beans or corn, you're looking at more like 2-3 cm below the surface.

3. Don't deprive them of sunlight.

Something that surprised me to learn is that our growing season has as much to do with daylight hours as it does with warmth; this is why, if you've ever tried to grow anything indoors in the winter, it's likely failed to thrive.  

If seedlings don't get adequate daylight, they'll get "leggy" - meaning they'll grow a long, unstable stem.  That's because their leaves are literally reaching for every drop of sunlight they can get.  If your plants get leggy it's not the end of the world, but it's not a great start either.

In Canada (I'm just outside the GTA), March and April BARELY offer enough daylight hours to start your seeds, but you can optimize the chances that your plants will thrive despite this.  Here's how:

• Choose a South-facing window and put them as close to it as humanly possible.  In spring, this is the only spot where you're likely to get direct sunlight during mid-day. 
• Don't start them too early - check the seed packets and do not start the seeds before the date provided.  In fact, if there's a range given, use the later end of the range.
• If you're using pots to start your seeds, fill them with soil until they're level with the top of the pot. In the early days of your seed growth, this will prevent them from being shaded by the sides of the pot.

4.  Don't let them dry out, but don't drown them either.  

Probably safe to say (without any actual scientific investigation) that this is the number one way that people kill their seedlings.  Seedlings in small peat pots or pellets (especially if placed in a South-facing window) will dry out in a hurry.  The soil should always be moist, so you'll need to water them every 1-2 days, which is a lot more than that spider plant you've been neglecting but still somehow seems to grow.  Here are some tips:

• Make sure you have the right tools in advance.  An indoor watering can with a narrow spout and a tray beneath your pots for overflow (so you can feel safe soaking them) are critical.  You may also want a small spray bottle to water your seedlings when they're tiny to avoid damaging them with an aggressive stream.
• Don't plant your seedlings if you're planning to go away for any extended length (3 or more days) of time in the following two to three weeks.  They'll die.  Luckily, we're all stuck at home right now anyways, so that's good news.  Ugh.
• Y'know those mini greenhouses you can buy at the store that come pre-loaded with peat pellets and have a clear plastic lid?  They're great at keeping the soil moist to allow your seeds to germinate, but as soon as those seedlings come up, you have to take it off permanently.  The amount of moisture and the lack of air circulation is a perfect breeding ground for molds that can attack the base of your seedling stems.  And here's the problem - unless you're planting all the same kinds of seeds in your greenhouse, germination is going to occur at different times; some varieties take 2 days, some take 3-4 weeks. This renders the greenhouse useless for those slow-to-germinate seeds, as you'll have to take the lid off as soon as your quick-to-germinate seedlings appear.
• If all else fails, speak moistly to them and see what happens.





PMJT knows...

Good luck with your plantings, and don't hesitate to DM me with questions @sowittilyougrowit on Instagram.  Have fun!