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.
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!
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!