07 Feb

Many beginner gardeners think that growing their own transplants – starting plants from seed and growing them on until they are ready to plant outside – is too hard. The truth is, if you have the right equipment and information, and you start with easy vegetable varieties, it’s not hard at all.

The easiest and most worthwhile vegetable for most people to grow their own transplants of, is the tomato. Tomatoes sprout easily, grow fairly fast, are very forgiving of transplanting, recover from mistakes fairly easily, and don’t require heat mats in order to get them started. Growing your own seedlings also gives you the opportunity to choose varieties which are available as seed but hardly ever as transplants at stores.

Soil for starting seeds

Don’t use garden soil! It contains weed seeds (unless you sterilize it) and it compacts too easily. The requirements for a good seed starting potting soil are:

  • Fine texture but remains aerated
  • Holds water well
  • Drains easily

Home-made compost can be used as part of a seed-starting mix if you sterilize it first (pour boiling water over, or bake in the oven – very stinky!) and sift out all the lumps. Mix it with fine peat and perlite or vermiculite. It’s better used for making mix for potting on plants once they have germinated and grown into seedlings – see the post on Making Your Own Potting Soil for more details on that.

I use commercial peat-based seed starting mix with no added fertilizer or wetting agent. You can also get coir-based seed starting soil which I haven’t tried yet, but probably will this year.

Fertilizer

Seeds don’t need any fertilizer for germination, as the seed has its own built-in food supply. After the seedling has 2-3 true leaves, you should fertilize very sparingly using liquid fertilizer in the water. That can be compost tea, fish fertilizer, liquid seaweed, etc.

Containers

Lots of choices here. Don’t forget that even if you choose plastic containers from the garden store, you can wash and re-use them many times over before they give up the ghost. Don’t be throwing them away after a single use!

Plastic flats with inserts and lids. This is an example of a Jiffy brand kit which comes with a plastic tray (flat), inserts which allow you to start 72 small plants in the tray, and a clear plastic dome lid.

plastic mini greenhouse for seed starting

Plastic mini greenhouse for seed starting (Amazon)

Recycled containers

Plastic eg yogurt pots, styrofoam cups etc standing on styrofoam trays. Must poke drainage hole in the bottom of each pot!

Cardboard tubes for seeds with long taproots or root veggies (may go moldy – doesn’t hurt the plants)

Newspaper pots
Use a “Potmaker” or roll newspaper round a small can or glass of the desired size, fold flaps under at the bottom and tape. Instructions for newspaper pots are here.

Commercial systems

There is a huge variety of elaborate seed starting “systems” available from different manufacturers. While they do work, and some people swear by them, you really don’t need them to produce good transplants – and they are expensive, and often made from styrofoam which is self-destructing and hard to recycle. So, I recommend that you try simpler equipment first.

Plantable, biodegradable containers are recommended for plants which don’t like their roots disturbed. You can use newspaper pots or cardboard tubes instead. Peat pots must be very wet when planted out, and remember to tear off the rim so it doesn’t stick up above the soil and wick water away from the plant. Jiffy pellets made from peat are easy and convenient but they leave netting behind in the soil (it’s supposed to be biodegradable, but in my experience it takes years to disappear). Coir pots are now available too, very similar to peat, and you can even find pots made from cow manure!

Tools for sowing

Plain old fingers work for many seeds. Some small ones may be easier to deal with using a tool, especially if you have big fingers or trouble with arthritis. Here are a couple of examples: I have used both of these and personally I prefer fingers, but you may find they work better for you.

Red scoop type seed sower

Red scoop type seed sower (Amazon)

Green dial seed sower

Green dial seed sower (Amazon)

Where to do your seed-starting

For the actual planting, you need a hard, cleanable surface that won’t be damaged by water. A hard floor underneath that’s also water resistant is a really good idea too. A tarp will protect a wood tabletop if you don’t have anywhere else, or you can even use the kitchen counter. It’s very convenient to have water easily available. My favorite place for planting is the basement kitchen in my house, where I can make a mess without anyone worrying!

Once your seeds are planted, you may need space for a light stand. Because the lights will come on early and stay on late for best plant growth, you may want to locate this somewhere where it won’t disturb anyone. I’ve had best success with mine in the basement or spare room, but it’s still usable even in my office, living room, bedroom, or on the stair landing! It all depends where you have a bit of floor space, electrical outlet, and either a water resistant floor or a piece of plastic under the stand.

Indoor Light Equipment

If you don’t have reliable sun on a windowsill in winter, a fluorescent light setup is the best way to grow your tender transplants indoors. You can do anything from suspending a work-light over an existing shelf or worktop, through building a simple light stand yourself, to shelling out big bucks for a commercial unit.

Lights

Bright Stik

  • One will barely light one narrow “windowsill” flat
  • Can’t replace tube, not economical

Shop Lights

  • Cheap
  • One will light up 2 regular size flats
  • Hang them anywhere

Don’t use incandescent grow lights

  • Not enough light
  • Too much heat

High Intensity halide lights

  • Very expensive, only for serious growers

Timers

It’s important to turn the lights on and off morning and evening to give the plants 16-18 hours of light a day, e.g. 6am – 11pm. A timer is much more reliable than memory! Since most shop-lights now have three-prong (grounded) plugs, you’ll need a timer that takes them – usually labeled as “heavy-duty” or “exterior”.

Heating pads or cables (optional)

  • Not necessary for most seeds
  • Helps with getting heat-loving seeds eg basil, peppers to germinate
  • Sit your tray on top of the water heater or fridge instead!

Electric Fan (optional)

  • For Intermittent breeze
  • Helps seedlings to grow strong and stocky
  • Makes adjustment to outdoors easier
  • Can have fan on a timer too
  • A cheap small desk or table fan works fine – whatever you already have.

Shelves or plant supports

You can use existing resources such as  an old table with books or cement blocks to hold up the lights, and the plants on the table underneath it, or a shelf unit with the lights hung from the upper shelves and plants on the lower ones. Whatever you use, work out a way to control the distance between the lights and the plants so you can increase it as the plants grow. That may mean raising or lowering the lights on chains, or adjusting the height of the plants by adding or removing layers underneath the trays. Whatever works.

The next step up is to build a light stand. My design for a home-made stand is available here (free).

Home built light stand for plants

If you have plenty of cash to spare you might want to buy one of the spiffy light stands available from places like Lee Valley Tools and Amazon.

Preparation for Seeding

  • Clean recycled containers
  • Dampen soil
  • Remove lumps
  • Fill containers
  • Tamp soil
  • Make a dent for seed(s)
  • Make labels (no kidding: make them BEFORE you plant the seeds so they are ready to use instantly)

Sowing seeds

How many to sow? To get one plant in each cell or container:

  • Expensive hybrids – one per container
  • Brand new seed – one per container
  • Cheap seed or old seed – 2-5 per container

Covering

  • The smaller the seed, the shallower you sow
  • Cover the seed with about 3 times it’s width and press gently to firm the soil and make good contact between damp soil and the seed. Don’t squash the soil down hard!
  • Tiny seeds may just be left on the surface
  • A few seeds need light to germinate and must not be covered (check the seed packet)

Watering

Water from the bottom by setting the planted container in a dray or dish of water until the surface is thoroughly wet, then allow to drain. Then cover the planted containers  with a transparent cover that keeps in most water – a plastic bag will do, or the transparent plastic dome you get with a kit – and place them under the lights.

Check the containers every day to watch for signs of sprouting. Once seeds start to sprout, gradually open and remove the cover to give them better ventilation.

As your baby plants grow, they are easy to care for.

Water from the bottom when the surface of the soil dries out. You are better off slightly underwatering than overwatering, but don’t let them wilt.

Once the plants have 2-3 true leaves (not the first seed leaves), start feeding them with extra diluted liquid fertilizer.

Move the lights up or the plants down as they grow, so the leaves stay about 2″ from the lights. If plants on the outer edges lean towards the light, turn and swap the containers around from time to time to even things up.

Potting On

We often need to move plants into a larger container once they grow too big for the small cell or pot we started them in. 3” or 4” round or square pots will do. Some plants (tomato, broccoli, lettuce) don’t mind having their stems buried to reduce legginess.

Seedlings to be re-potted should be watered and allowed to drain several hours beforehand, so they are thoroughly damp but not sodden.

  • Prepare larger pot with damp soil and a hole the same size as the seedling’s root ball
  • Squeeze bottom of cell you want to get plant out of
  • Cage fingers over remaining cells
  • Turn cell pack upside down and push desired seedling out of cell into fingers
  • Plop into prepared hole
  • Firm soil around seedling
  • Water well from the bottom

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One Response to “Grow Your own Transplants”

  1. 1
    Daniel Wilkie Says:

    Brilliant Article, Really imformative

    One product that will help seeds germinate and increase survival rates whilst improve nutrient & water take up and are mycorrhizal fungi.

    These tiny fungi can be added as a seed coat to damp seeds before planting. When the seed starts to germinate the fungi will attach themselves to the root and expand the root surface area by up to 100 times! These fungi act as a feeder to the roots, collecting nutrients that the plants need from the soil and passing them into the roots.
    In turn the plant feeds the mycorrhiza with carbohydrates so creating a biological partnership.

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