Starting seedlings

It’s that time of year to start indoors the plants that can benefit from a head start.  For example, celery (pictured above), peppers, eggplants, and tomatoes.

The farmer’s almanac has an excellent planting calendar that you can use to determine when to start your seedlings.  I may start celery and peppers a little earlier than suggested, but planting tomatoes earlier may result in them getting rather unwieldy before it’s safe to move them outside.

Why start your own seedlings?  It’s cheaper, you have more choices in terms of varieties, there is less shock to the plants when moving them from your home to your backyard (as opposed to from a commercial greenhouse), and, most importantly, it’s thrilling to watch the babies grow day to day!

For more information on starting seedlings, refer to the articles we published last year:

Happy planting!

Thinning vegetables

Many vegetables have small seeds that are difficult to sow one at a time.  As a result, you invariably end up with too many small plants close together, fighting each other for the same space, air circulation, and nutrients.  In the case of beets, multiple seedlings almost always arise from each seed (which is really a clump of 4-6 seeds).

Here is a list of vegetables that often need to be thinned out:

  • Beets
  • Carrots and parsnips
  • Lettuce and other greens
  • Turnips and rutabagas
  • Various herbs, such as basil and cilantro

For greens and herbs, simply pull the plants out by the roots.  You can use these plants whether they are big or small.

For very young root vegetables, snip the tops off the extra plants; they will die back naturally.  Throw the tops into the compost.

For older root vegetables, wait for a day when the soil is quite wet, and slowly pull on the tops until the root emerges.  Keep a small spade or stick handy to gently dig out the root should the tops break off, leaving you nothing to pull.  Ideally, though, you should minimize disruption to root vegetables.  Carrots, for example, may fork is moved (although their shape does not affect their taste).  I gently pack the soil back around the side of the carrot that is bared when its neighbour is pulled.

Leave enough space for each plant to grow comfortably without pressing up against any others of its kind (or any other neighbours).  This will vary according to the type of plant.

Want to reduce the amount of thinning you have to do?  Try making your own seed tape.  Although you may find more gaps in your garden (where seeds along the tape did not germinate and did not have backup seeds to fill in), at least you will have less precious seedlings to pull.

School plant sales

It’s that time of year when school associations often organize plant sales to raise funds for various project.  This is a good opportunity to purchase flowers and vegetable plants that will thrive in your particular area.  Here at GIMBY, we are preparing some pepper, eggplant, and kale seedlings for a local sale tomorrow.

Check out your local school’s calendar of events soon to see if you can purchase–or donate–some plants!

Repairing damaged seedlings

If, in the course of transporting, transplanting, or hardening off your plants, they are damaged, don’t despair.  In many cases, you may be able to nurse your injured plants back to health.

Maybe they just need a little extra support

The pepper plant pictured above was very briefly knocked over; as you can see, its stalk is bent but not torn.  In this case, we’ll prop the plant up against a window or wall so that the bend is eliminated.  As the plant grows, the stalk will thicken, and reinforce and repair the bend.

Splints: not just for animals

In the case of a partial tear or a badly crimped bend, you can construct a splint for your plant.  Obtain two chopsticks, pencils, or other instruments that about as wide as the stalk.  Position one close to the stalk where the lean or break is, and one directly opposite.  Insert them about an inch into the dirt (being careful not to disturb the roots), then wrap electrical tape or yarn around the splints to encase the stalk inside in an upright position, with the tear sealed or the bend corrected.  Ensure that the tape or yarn does not touch or squeeze the stalk.  It may take a few weeks for the stalk to heal.

Dirt heals all

If the stalk is partially–but not completely–torn, you can often save the plant by simply burying it in the dirt!  That is, replant the seedling so the break is underground.  With tomatoes and members of the cucurbitaceae family, this is often all you need to do to heal the wound.

Leaf it alone

Don’t worry too much about torn or damaged leaves.  As long as the leaves have not been entirely shredded, and the plant has not lost all of its leaves, it should recover.

Care and feeding

In all cases, ensure that your injured plant is in good quality soil, with access to the appropriate amount of sunlight and water.

Problem seedlings

What a sad pair.

The leaves of the pepper (on the left) are looking dry and wilted; it looks like it’s outgrowing its container.  The tomato (on the right) is growing more horizontally than vertically.

The wilting pepper and the wandering tomato: a love story

Wilting leaves

If your seedlings’ leaves are wilting, there could be a few causes:

  • Too much sun and or heat coupled with not enough water.
    • Ensure that the soil does not dry out; move the plants to a cooler / shadier location if needed.
  • Too small a pot (the plant is getting root bound).
    • Move the plant into a larger pot.
  • Too much fertilizer.
    • Use fertilizer sparingly.  In potted plants, fertilizer can’t get washed away, so it may build up.

Leggy plants

If your plants are getting tall and spindly, and they are leaning towards the sun, it’s because they are not getting enough light, or the light they are getting is not intense enough.

Move them closer to their light source, and increase the duration of light they receive.  You can supplement natural light with artificial light.  It’s not necessary to have grow lights; shop lights and the like will do so long as they’re not so hot that they’ll scald your plants.

Some plants, like tomatoes, don’t necessarily suffer long term effects of being leggy seedlings.  When you transplant them outside, simply bury them deeper in the soil so that their vertical height is diminished.

Here’s another sad tomato.

Curled leaves

Leaves curled under

If a plant is not dry, and its leaves are curled under, it may in fact be over-watered.  The solution to this problem is simple–water it less.

Starting seedlings indoors, Part four

Up until now, our seedlings have had a pretty easy life.  They’ve been thriving in a temperature-controlled environment, sheltered from extreme temperatures, rain, and wind.  We want to put them outside in a few weeks, after it looks like the chance of frost has passed.  If we just moved them outside from their little comfort zone, without any preparation, they would likely do very poorly.

Seedlings have to be hardened off before they can be planted in their beds.  This process gradually exposes them to the elements.

Indoor preparation

You can do a little preparation inside to strengthen your seedlings.  On warm and slightly windy days, open some windows to let a cross-breeze flow across the path of your seedlings for an hour or so.  This will expose them to the wind; their stalks will become stronger.  Alternately, you can use a fan; place it some distance away and keep it on low.

Hardening plants

Start 7-10 days before transplant.

  • Start on a mild day.  That is, don’t pick a day that’s too hot or one that’s rainy.  If it’s cold, wait.
  • For ease of transport, consider putting your seedlings on a tray that you can easily carry in and out of the house.
  • For 2-3 days in a row (provided the weather is not inclement), move your plants outside for a few hours.  Place them in a sheltered, shady spot, such as against a building or under a tree.  Do not place them high up on a table or deck where they’ll get the full brunt of the wind and sun.  Each day, increase the amount of time they’re out by an hour or so, so that the first day, they are outside for 1-2 hours, then the next day they are out for 2-3 hours, and so on.  Gradually reduce the amount of water they receive, but don’t let them wilt.
  • For the next 7 days, place them out in the morning sun for a few hours, then move them back into the shade for the bulk of the day.  Gradually increase the amount of time they spend in the sun, so that, again, they spend 1-2 hours in the sun one day, then 2-3 the next, and so on.  Ensure that they don’t get too hot; if they begin to wilt, move them into the shade, and water them.
  • After a week, your plants should be able to tolerate the wind and sun for the day.  So long as the forecast still looks favourable, you can plant them.
  • Plant them on an overcast day so that they don’t get too hot, and water them well.  Apply an organic fertilizer to give them a boost and to minimize transplant shock.  Keep them watered as they adjust to their new life outdoors.

Uh-oh, the forecast changed!

In the event that the forecast changes, and strong winds, heavy rain, or cold temperatures are forecast, your plants may still be okay.  Temporaily cover them with row covers, plastic containers, plastic sheets, or anything that will shield them from the elements without damaging them or eliminating their exposure to the sun.  If you’re using some sort of sheet, just make sure to place something under it to prop it up so that it doesn’t flatten your plants.




Starting seedlings using soil blocks

Rather than using seed trays and pots to start seeds, you can use a mold to create soil blocks.  Soil blocks are squares of dirt that are made using a specific mixture of soil which holds it shape.  These blocks are placed on a tray in a grid; one seed is placed in each block.


Large and small soil block molds, and a set of four small soil blocks


Soil blocks offer several advantages over containers:

  • It is easier to water trays of soil blocks; just pour water into the tray and it will spread upwards into each block.
  • Seedlings are unlikely to become root-bound, because they are surrounded by air.
  • When you transplant your seedlings, their roots aren’t disturbed, because you can simply plunk the plant and its soil block into its new location.  You don’t need to tear it from its plastic container.
  • You’re not wasting plastic pots and containers, which often become fragile and useless after a couple of seasons.

How to use soil blocks

Purchase soil specifically made for this purpose, or make your own by mixing three parts finished compost with one part garden soil and four parts coco peat.  Potting soil is too light; other soils may be too dense.  You need a soil mixture that will retain its shape, hence the recipe above.

Add a fair bit of water to the soil; it should be quite wet, but it should hold its shape.  Maybe if you have kids, they would like to help with this step.  🙂

Put this mixture in a shallow tub and press the mold into it using the flange.  You may need to twist the mold or push it into the mix a few times before its blocks are full (check the bottom to ensure it’s full before you empty it).  Press the mold onto a sturdy, airtight tray and release the blocks.  Most molds make a slight dimple within the centre of the block; into this, place a seed, then cover with a bit of soil as needed.

Please the tray in a sunny or artificially lit area.  Keep the blocks moist by filling the tray with water.

The Lee Valley molds linked to above come in two different sizes–so when a seedling outgrows its small soil block, you can create a larger block to insert it into.

Starting seedlings indoors, Part three

Last week, we saw that a lot of our pepper seeds had sprouted. I removed the ones that had sprouted from the heating mat so that it would not damage their roots. They are now in larger containers, where they’ll remain until they get too close to their neighbours, and then I’ll move them into their own individual pots. Some gardeners don’t like to transplant their seedlings too many times, but I don’t like to break their roots to separate them from their neighbours when I finally move them to the garden, nor do I like them to get too rootbound. So, they will be transplanted once more.
Some plants, such as the celery seedlings below, don’t grow very quickly and don’t have deep roots, so they can stay with their neighbours for quite a bit longer. They were started 10 days before the peppers but they are much smaller, though some have begun to grow their secondary set of leaves (the ones with scalloped edges).

Celery seedlings with secondary leaves

So, we’re in maintenance mode now

Keep the plants watered (but not soaked), and ensure they get adequate sunlight and or artificial light, as per the recommendations for each type of plant.
It is important to rotate your plants frequently so that they grow straight. They’ll naturally lean towards the sun or other light source.

Seedlings leaning towards the sun
I usually rotate them every couple of days.