Friday, February 26, 2021

Seed starting for beginners

Can’t wait! Just can’t wait, and I know I’m not alone. My recently arrived seeds are sitting in the refrigerator and I can’t wait to start them. Sure it’s too early for most seeds, but the worst thing that can happen is the plants will take over the house before I’m able to plant them outside . . .

The answer of course is to read the instructions on the seed packets and wait. When it says start four weeks before my last frost (24th of May, more or less) it means I shouldn’t start them until the 24th of April — two whole months away. Here are a few tips and reminders.

Propagation Containers:

Anything that can hold a couple of inches of soil and has drainage holes in the bottom will do. For individual containers, use coffee cups — plastic or Styrofoam are fine, and yogurt cups are great too

No need to be fussy about containers as long as they’re clean and have drainage holes in the bottom. It’s also a good idea to poke or slice a few holes in the sides too. It allows for better drainage and lets oxygen get to the roots, which is very important. If you’re recycling last year’s containers, be sure to wash them well to prevent the spread of any fungal diseases.

All containers will need a plastic cover to keep up the humidity level. However, the cover should not be totally airtight and is best removed as soon as germination occurs. If you can match a plastic cake cover up with a pot the same size you’ll have the perfect propagation chambers, or you can slip a large one over a number of individual pots. Plastic stretch-wrap over the pots will also do the trick, but poke a couple of holes in it. Clear plastic produce containers work well.

Soil Mix:

A soil-free mix is an excellent medium for starting seeds, especially if you’re a beginner. These mixes are usually made up of peat moss with vermiculite and perlite added. Regular potting soil is a little too heavy and if not reasonably sterile (potting soil is not actually sterilized) it will allow the dreaded damping off fungi to develop. This is what causes seedlings to keel over and die for no apparent reason. There is a reason: they’ve been attacked at the base of their stalks right at the soil surface. Avoid using garden soil for this same reason.

Once the seedlings begin to grow well, some liquid fertilizer will be necessary, especially with the soil-free mixes, but check the instructions and use at half strength or less. Too strong and there’s a chance the little guys will be burned.


It’s essential for plant growth, but not for starting all seeds. The seeds of calendula, gazania, delphinium, pansy, verbena, and vinca are typical of those that prefer to be left in the dark until they germinate, but check daily because they will need light as soon as they do pop up. A simple LED grow light fixture suspended about 100cm or so above the seed trays is a perfect light source. Use a timer so that the lights are on for around fourteen hours each day. If you intend growing a large number of seedlings, use a small fan to provide gentle air circulation.

Starting seeds on a window sill is fine, but never in full sun. A container with a clear plastic cover placed in full sun will get hot enough to poach an egg. A south facing window with sheer curtains is as good as you can get.

If seedlings begin to look like giraffes on stilts it means they’re not receiving enough light; likewise if they begin clawing at the window. Rotating the pots will straighten them up. If your windows are poorly located for good light, don’t give up, focus on growing shade loving plants such as impatience.

Don’t forget to move seed trays away from windows in the evening as it will get too cold there. Correct temperature is very important for seed germination. Most seeds, but not all, germinate best at a steady temperature of around 20 - 24C. After germination, the temperature lower.


Keep the growing medium for seeds and seedlings moist but not wet. Watering from the bottom up will cut down the risk of damping off disease. Use room temperature water and check at least once daily, because seeds will not germinate if the soil is allowed to dry completely.


Another reason seeds don’t germinate is because they’re planted too deeply. In fact, some seeds need only be scattered on the surface. A tiny seed, germinating too far down, will use up its food store before it ever reaches the light where it can begin making its own food through the process of photosynthesis. Follow the instructions on the seed packet closely. If there are none, or you’ve lost the packet, plant at varying depths as deep as two to four times the size of the seed. This will ensure a degree of success.

There’s lots more to starting seeds, but if you follow these basic instructions you’ll be successful, maybe even too successful. Now, what you should do is clip and save this article until it’s the correct time to start seeds — unless you can’t wait. But just remember, the house can get pretty steamy when it’s brimming with enough tomato plants to attract Campbell’s attention.

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