Carrot Germination by Boiling-Water Method
Question from Matt: I was fortunate enough to attend your presentation at the last SD Master Gardener Seminar. At that time, you suggested speeding up the germination period for carrots by pouring boiling water over the freshly-sown seeds. Although you said that boiled-water germination would likely occur within 3 days, I have not seen any germination after 5 days. How long should I wait to see if there is germination before replanting with more seeds?
Answer from Pat: I am glad you tried the trick of planting carrots and pouring on the boiling water after planting for quick germination, but sorry it didn’t work. As I said that day, I tried this trick with potting soil and it did not work. However, it always worked in my garden soil outdoors and I used this system numerous times over a period of many years. It also worked at the school garden, and in that case the seeds came up in three days. I wonder if there were other factors at play here? For example, were the seeds covered over too deeply? Was the soil below the seeds too dry? Were the seeds sprinkled after planting to keep seed damp after planting? Carrot seeds must be kept wet to make them germinate and this is true even when using boiling water to scarify the seeds. Carrot seeds also need good contact with the ground which is why we pat down the row but they need to see some light, which is why they must not be covered over too deeply.
I cannot explain why the seeds didn’t come up, but since they did not come up within five days my guess is that they are not going to come up and I don’t know the explanation. The only time this system failed for me was when I tried it on seeds planted in a pot of potting soil, which made me think the drainage was too good and the seeds just didn’t stay damp enough. Another possibility is that when I poured on the boiling water the seeds got buried too deeply by mistake or maybe the seed was old. Carrot seeds are only good for about three years.
Thank you for your email, which is helpful. I think a couple of the factors you mention are in play. I did plant in garden soil, but it was relatively dry and “fluffy” because I had worked in a large amount of compost 2 weeks earlier and had tried to dig deeply because I knew I would be putting carrots there. I sowed the seed by mixing it with sand, and in a depression made from a garden hoe handle, like you suggested. But, when I poured on the boiling water, it the soil compressed and left a definite depression showing the row. I put the potting soil on top pretty lightly, but it seems likely that the seeds were driven too deep by the combination of the dry, fluffy soil and the boiling water. I also didn’t realize that I should pat down the sown row to ensure contact with the soil. Live and learn.
Because seed is inexpensive, but time is precious, I’ll go out and buy some more carrot seed this weekend and try again.
Best wishes, Matt
I want to thank you so very much for this complete explanation. It sounds as if the seeds got buried too deeply just as you have indicated.
You did exactly right making the soil fluffy with organics for carrots but then you would need to make sure it’s fully moist, even wet, in order to germinate the seeds. Usually putting the sprinkler on the bed and really soaking the bed thoroughly the night before planting accomplishes this but if drainage is too great, sprinkling seeds twice a day to keep them moist might be necessary for germination. Carrots won’t germinate if seeds dry out.