Gardening Tips: How to Read a Seed Catalog

What to do this week

Looking at some of the better seed catalogs can be a bit confusing for the uninitiated. A well-written catalog is full of useful technical information, but that’s not much use if you don’t know what any of it means. This week, we’ll take a tour through some of these terms so you can get the most out of what you’re reading.

First, and nearest to my heart as a seed-saver, is telling which varieties are hybrids. This is important because hybrids will very often be high performers in the garden – you’ve heard of hybrid vigor and all – but will not reproduce true to type from seeds collected from the fruit. The ones I want are called open-pollinated but are very seldom identified as such in the descriptions. Hybrids are always listed either as hybrids or F-1, though you might need to read the text through carefully to find the reference.

Source: Natural Resources Canada

Source: Natural Resources Canada. (Click to enlarge)

I do grow some hybrid cultivars – onions, sometimes sweet peppers – and I have no philosophical objection to using hybrids; the basic techniques have been around for at least a few hundred years. The process of isolating parent lines and repeated crossing is expensive for the seed companies, however, which is why some specialty seeds can run as high as a loonie apiece. My Scottish soul objects. Plus, companies focus their efforts on varieties that do well in the larger population markets and under perfect conditions, neither of which describes Cape Breton. It’s a reasonable business decision, but it’s why I find the hobby of seed-saving so rewarding in fringe areas like ours. Open-pollinated cultivars come in hundreds more varieties, especially if you join a seed-saving and sharing organization. [Insert shameless shilling for Seeds of Diversity Canada here.] I’ll talk more about garden planning for seed-saving in coming weeks.

Another confusing item in a seed description is the figure for days to maturity (DTM). These can vary widely depending on conditions in the company’s test gardens. Few seed companies produce their own seeds, they just trial varieties in test plots. Naturally, the test plots in the Maritimes are going to be different from those in southern Ontario or the West Coast. If I buy tomato seeds from William Dam that say they will ripen in 65 days, I’ll be lucky to see them by 80, or at all, some summers.

So many things affect the DTM. Cold soil delays starts and slows nutrient uptake. Cool weather can affect or suppress flowering and fruit set. Some tomatoes will actually drop their fruit if the weather goes below 10C and beefsteak tomatoes especially can develop blossom-end rot due to poor calcium uptake in acid, cool, clay soils. You can get around some of these environmental constraints with the use of raised beds, south-facing, sheltered slopes, good compost, soil management and things like that. Microclimate is everything here. But be aware that even for a regionally based seed company, those days to maturity are mostly aspirational in Cape Breton. And don’t forget — those days are measured for transplants, not seeding dates, in the case of tomatoes and peppers and so on. You add another eight weeks or so for starting things indoors.

Other useful tidbits in a good catalog include things like seeding rates and disease resistance. It’s helpful to know, for example, that no matter what size bean you’re planting, the seeding rate should be 7 to 8 per foot. If you want a 100-foot row, you will need a seed count of 800 beans. This information is so useful, I will weigh out my beans, calculate the row feet they are expected to plant, and measure that distance out in the garden. That way I just walk up and down the rows sprinkling and adjusting as I go. It takes some practice, but it’s worth it for large areas.

On the flip side, if your seed packet has an 80 bean count, then you will have enough for 10 feet of row. This method works for peas and other large-seeded crops as well. All seed packets (if not all seed descriptions) should have a recommended seeding rate that allows for missed germination and reduces the need for thinning. (Good catalog include the rate on the packet and in the description.) They will often also have a recommendation for spacing between the rows; however I find that they usually lowball these. Diseases can take hold easily in our humid climate and wide row-spacing and good air circulation are important coping strategies. If a vegetable has proven resistance to certain viruses, it should be listed in its description. If you are interested in seed-saving you can also incorporate some selection for resistance traits over the course of the summer.

Next week, we’ll look at the seed catalogs again with garden planning in mind. It’s easier to erase the mistakes made with pencil and paper at this time of year than to be overwhelmed by crowded, straggling plants in the middle of summer.



Market gardener, farmer, workshop leader, seed-saver, political candidate and mother, Michelle Smith has spent over 30 years coping with the challenges of our bioregion and in the process has built a store of practical and technical knowledge. The Inverness resident has served on the board of Seeds of Diversity Canada and represented Alternative Producers with the Federation of Agriculture but can do nothing about her hair. She is pictured with a head of Club Wheat, a seed that shares her approach to hairdressing.




Backyard food gardener Madeline Yakimchuk caught the food-security bug in the early ’90s through Cuba’s Urban Agriculture Department, taking her first permaculture course and planting her first garden. She can often be found discussing food security, nurturing a plant-based lifestyle or trying to give away vegetables. Professionally, she is GRYPHON media productions but sometimes uses la bruja in her volunteer work, most notably in managing the garden column, which begins life as a telephone interview.





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