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When to Start Seeds Indoors - With Free Printable Seeding Guide

Updated: Jan 7

If you are like me, you are anxiously anticipating and counting down the days to when you can start seeds for your 2022 garden! For fellow Albertans, or others with similar frost dates, I will share with you when to start seeds indoors. If you live in a warmer climate these dates can be adjusted according to your last expected frost date. Starting plants from seed indoors is not only fun but it ends up costing a fraction of the price that it would to buy these plants already started at a greenhouse!

Vegetable seeds with a seed tray for the seeds to be started indoors in Calgary Alberta, Canada zone 3 growing zone.

To begin with I will discuss what supplies I use for starting plants and then I will share with you the dates I like to plant my seeds indoors for my zone 3 garden near Calgary Alberta.

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The best soil for starting plants indoors

It is helpful to have a good quality potting soil mix. Pro-mix and Sunshine mix are good brands in my experience. If you attempt to use any compost or soil from outdoors you will most likely end up with soil gnats, aphids and possibly more problems. I do not suggest this rout for growing indoors. (Trust me, I have learned this the hard way!) The last few years I have been using Sungro potting soil and have been very happy with it.

Sungro soil used for starting seeds indoors in Alberta to plant in my zone 3 garden near Calgary.

Surprisingly, good quality potting soil mixes are actually soilless, containing no natural soil. They are great for retaining moisture but also not becoming waterlogged (which can cause seed and/or root rot). Potting soil is not good for vegetable garden beds (unless mixed with 1/3 compost and 1/3 top soil) but is wonderful for growing plants in containers! Be mindful of the fact that although this soil can retain nutrients, it does not contain many nutrients. Your plants will benefit greatly from fertilizing once every week or so. Check out your local garden center or hardware store for more potting soil options.

The best grow lights for staring seeds indoors

It is not necessary to use grow lights if you have a sunny window but you will end up with less leggy, stronger and all around healthier plants by using grow lights. I started my seedlings indoors without grow lights in a sunny window for 2 years before I made the leap and purchased grow lights.