Alice Spenser-HiggsWhy seeds fail and tips for success

I could also call this ‘Confessions of a ‘slapgat’* or seed hoarder’, or ‘Now I know why seed companies gnash their teeth!’ It’s a magical moment when seeds germinate, but when they don’t, it’s easy to get discouraged. After enthusiastically sowing all the seed for my fledgling balcony garden, the results were mixed – 100 percent germination of the broccoli and rocket; about 80% of the spinach baby leaves, and dismal for the baby carrots, baby cabbage and beetroot.

Shameful, old seed packets shoved in a drawer and forgotten about!

Shameful, old seed packets shoved in a drawer and forgotten about!

To find out why I spoke to Chris Varney at Kirchhoffs Seeds (very helpful guy). His first question was:

How old is the seed?

I checked the seed packets and then it all became clear. The carrots, beetroot and cabbage are all four years old, the broccoli expires this year, there’s no date for baby spinach seed, and the rocket was bought a month ago.

What happened was this: a few years ago, for some reason, I became wildly enthusiastic about sowing veggies from seed. So I bought a lot of seed, put it in a drawer with lots of good intentions and promptly forgot about it …until a month ago when I rummaged around to see what I could find! Ring any bells for other gardeners out there??

Chris (with a quiet smile in his voice) gave me a quick lesson in seed viability:

1. Viability varies from veggie to veggie but the average viability is two to three years. The older the seed, the less germination success. From tests they have done, fresh seed has between 85% to 100% germination rate, while seed four years and older drops down to about a 15% germination rate.

2. Seed life also depends on storage conditions. The best is in a cool dark place, like a cardboard box. On that at least I get full brownie points.

3. Some veggies have a longer viability, such as spinach. I will be able to put that to the test as I have LOTS of four-year-old spinach seed!

Success: Beautiful rocket, spinach baby leaf and a few beetroot, for eating as baby salad greens

Success: Beautiful rocket, spinach baby leaf and a few beetroot, for eating as baby salad greens

Other reasons for seed not germinating:
Incorrect planting depth.TIP: Mix fine seed with mealie meal; helps to see where you have sown. Cover very fine seed with a fine layer of germinating mix/ sifted potting soil/ compost. Lightly firm the soil so that the seed makes contact with the soil.

Soil drying out during germination. All seed companies are unanimous: this is the major reason for germination failure! TIP: According to Sean Freeman of Living Seeds, when the germ of the seed emerges it needs to be into moist soil. Should the soil be dry, even if it is for 30 minutes, the germination will fail. That is why all seed packets stress consistently moist (but not over wet) soil.

Germination mix too fine. TIP: There is a difference between germination mix and seedling mix that is available through garden centres. The germination mix is coarser than the seedling mix because the seed needs little pockets of air and water during germination.

Incorrect germination temperatures. TIP: Kirchhoff’s indicates the optimum temperature for sowing on the back of its seed packets. Interestingly, the other two South African seed companies do not. They just indicate the season.

The moral of the story is read the instructions on the back of the seed packet; including the date stamp. At least now I don’t feel so bad about my 15% germination of carrots!

* Slapgat is Afrikaans for lazy!

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Alice Spenser-Higgs

About Alice Spenser-Higgs

I have been a garden writer for the past 12 years. It started with an epiphany in the riotously colourful Archbishop’s garden in Braga (Portugal). I thought: I can write and I can garden so why don’t I put the two together! Before that I was a features and arts writer, with a 10 year sojourn in politics (garden dirt is cleaner!). I contribute to garden magazines and newspapers, as well as writing for Ludwig’s Roses, BallStraathof/Kirchhoffs seeds, Healthy Living Herbs and Garden World. This blog is for recording my own garden experiments and sharing that experience in a way that is, hopefully, practical and helpful for other gardeners.

7 thoughts on “Why seeds fail and tips for success

  1. helen mckerral on said:

    Alice, I had to smile when reading your blog because I do the same thing! I get enthused about collecting my own seed, and have cupfuls of aquilegia, parsley, coriander, perennial spinach etc in my garage, but am always surprised when I come across them – always just after the optimal planting time, of course!
    One tip for carrots and parsnips (from my grandmother) is to firm down the soil VERY firmly, ie by stamping your way along the row, before watering, to remove excess air pockets.

    • Alice Spenser-Higgs on said:

      Hi Helen, thanks for the carrots tip. I hoard the experience of our mothers and grandmothers like gems because so much of that knowledge and experience has died out. My mum was a great gardener and I wish I had consciously learnt more from her. I picked up an interesting germination tip from another gardener – if you are worried about the viability of seed, sprinkle some seeds on damp cotton wool or kitchen towel and mist them every few hours to keep them moist. If the small little growth tips havent started to emerge in at least half of the seeds within three to four days, turf them out! I am going to try it.

  2. I reckon I can claim the slapgat prize (what a fabulous word! I’m going to find a way to work that into a conversation today) with some Diggers Club flannel flower seeds that say expiry 2003!

  3. I also do exactly that! My special box is full of lovely seeds that I forget to plant. I bought new seeds today just after reading today, but this time i will plant quickly them and hopefully they will come up. Sam

  4. Well, to avoid the seed slapgat ( call it slapdash here), I always plant my vegies from seedlings. Somehow , I just can’t seem to handle seed successfully. Either its too fine and I dont scatter it enough and it comes up way too crowded, or I misjudge the planting depth and they disappear. I should try harder, particularly when I see your gorgeous rocket spouting profusely.
    I had some french bean seeds given to me last year. Would they still be ok, do you think?
    Just planted out a bed of pea and snow pea seedlings, so perhaps I could try bean seeds on the other side of their support wire?

  5. I also like to work with seedlings because all the angst of germination has been carried by someone else. However, there are some veggies/ herbs that really grow so well from seed and rocket is one of them. It is almost foolproof and really worthwhile to grow from seed. Mustard also grows easily from seed.

    I find it easier to work with larger seed like baby marrow, patty pans, butternut etc because you only need two seeds per individual hole. I always plant two as insurance. If both come up then I transplant the other one. Even though I have a small garden I grow cucumber, butternut and gems as creepers up trellis and along garden walls.

    Another reason for going with seed is that seedlings are not always available in the veggie variety that I want. This particularly applies to heirloom varieties. I also find it helpful to sow seed in little pots and later plant out the seedlings when they are bigger and more established.

    Re bean seed, last years seed will still be perfectly fine. In Pretoria, SA, it is too late to plant out green bush or runner beans, but still okay to plant broad beans (which I haven’t done because my veggie garden is almost entirely in shade in winter).

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