Beet seeds are very sensitive to soil temps, so that may be the problem.

That's interesting, but https://aggie-horticulture.tamu.edu/archives/parsons/earthkind/ekgarden15.html says that the optimum soil temp for beet germination (and a lot of other things) is 85F. My soil is not that hot. Many other sources say 65-85F. For greens - spinach, lettuce, etc., lower soil temperatures are definitely important.

FWIW, my soil temperature a month ago was 78F, and now it is about 70F.

I thought that beets, like peas and lettuces like a cooler soil. All three have germinated in my now cooler garden pots.

Then there is the Phase of the Moon thing.

As I said below, all the references I have say that beet germination is best at 65-85F. Mine is 70-75F. TAMU Extension says 85F is optimal. Your source? Where is it said that cooler temperatures are best?

Yes, the phase of moon thing is where gardeners get deluded by bright things in the night sky.

Well, I've asked around about this, and the most popular explanation for delayed germination is that my soil temperature is too high. Except, according to real research and extension expertise, it isn't. I welcome pointers to responsible growers who have determined that 75F is too hot for beet seed germination. Never seen any. The funny thing about that explanation is that, horticulturally, I've never seen anything that grows slower when hotter. Heat can certainly prevent germination, and it can certainly kill things, but it doesn't slow stuff down.

Beets are cool weather crops mainly because beet root tends to crack and lose flavor at higher temperatures. Beets can also respond to high temperatures by bolting. My fall-sown beets blast right through my vicious summer. They don't stop growing when it gets hot.

I'm forced to assume we're looking at physical scarification by soil degradation. Beet seeds are known to germinate more readily when physically scarified. If anything, that soil degradation will happen faster when warmer. What I don't understand is why some people and seed packages as well seem to say that they just germinate in a week when planted without extra effort.

Still one of the greater mysteries of vegetable gardening.

Oh OK.... just for the fun of it all I went out and took the soil temp right next to a baby beet sprout... 50 degrees F. All the pots get morning sun only and are in shade in the afternoon. Our nights have been fairly cold in the 30s, days in the high 50s. The area is very protected and has it's own microclimate, so freezing temps are rare in that spot. Beets, peas and lettuces are happily growing in these conditions.

And, I didn't scarify any seeds.

We're talking about germination time. Not whether you can get them to germinate. I have, right now, about sixty beet seedlings.

I scattered the seeds about two weeks ago; digger turned everything over looking for grubs.... grrrrr; babies are back in full strength, but some no longer deep enough.

I'm not arguing with the fact that some people manage to get beet seeds to germinate promptly. The seed packets say 5-10 days so, unless they are lying through their teeth, that must be true for at least some growers. The fact of the matter is that sometimes they take a lot longer to germinate, and I'd just like to understand why.

This is interesting. I just heard back from Burpee, and they say that their Detroit Dark Red has a germination time of 14-21 days. Seed Savers says that these same beets should germinate in 5-10 days. Big disagreement there! I haven't grown those for a year or two. Seed Savers Burpee's Golden (which I'm growing this year) says 5-10 days on the packet. But Burpee (which oughta know about those beets!) says that those same seeds should take 14-21 days! Online, loads of sources say 5-8 days for beets in general.

So I'm beginning to suspect that those small germination times for beets are simply mythology that, in a few cases, and Seed Savers in particular, has propagated to some seed packets, and the reason for the lengthy germination is precisely because of the need for soil scarification.

For me, fall planting is always more unpredictable and frustrating than spring planting because of the soil temperature. Germination is always uneven and delayed. I plated a whole bunch of romaine 5 weeks ago. Some is already 1/2 inch tall with 4 true leaves, some just emerged this morning, and some areas show no activity at all. The growing conditions are identical (raised beds, potting mix and compost). Grrr.... Last year I started lettuce in the house under lights and that worked really well, but it's not something I can do on a larger scale. Patience *sigh*...

Root growth often far precedes leaf growth. Perhaps the estimated germination time is talking about the earliest growth of the root from the seed, rather than when the gardener can see the first few leaves forming.

"Germination", to me and most anyone, means when the plant appears above the soil line. No one is interested in how long it takes for roots to come out of a seed. Not any practical value in that.

I would consider germination to be whenever either roots or cotyledons first emerge from the seed.

tj

When, on seed packets, they give "germination" time, they're talking about appearance above the soil. But that's fair that you can define it any way you want. To a botanist, yes, emergence of anything from a seed can be considered germination. But to a gardener, that's not the case.

To get back on topic, as to the case I laid out below, I'm being somewhat diplomatic by calling 5-10 day germination for beets just a myth. Whatever you want to call it, it's likely viral, and multiplies rampantly, where someone said it, so another person said it, and then a third person said it because two others did. That doesn't make it right.

Now if someone has ever seen beets appear above the soil 5-8 days after planting, please weigh in here and tell us what you're doing!

Everyone seems pretty focused on soil temps here. That may not be the issue. I have great success, for instance, in sowing spinach in April/May (super cold) here in Minnesota. But when sowing at slightly higher (which should promote bolting) temps in early fall, success is nearly ZIP.

So here are a couple of other factors that might be taken into account:

1) Seed freshness. Some seeds can be dormant for years with not much reduced vitality, others not so much. Not sure about beets.

2) Day length.

I'm way north, so day length varies hugely from equinox to solstice. So when I plant lettuce or spinach or beets late in the season, the fact that day length is decreasing at the same time seems be a signal, because for sure, soil temps change through the course of a day, depending on radiant energy (i.e. how much sun is hitting the soil). Even if soil temps are "high enough," but for a decreasing period of time per day, I would think that would certainly be a signal to the seeds/plants: "Not a great time to be putting growing energy out there."

I have definitely observed re indoor plants that once we hit about January 6 here, all my plants (orchids, amaryllises, violets, some over-wintered tubers/tropicals/) take notice and begin to perk up and shoot new growth. Conversely, anytime we're getting close to or shortly after the fall equinox, getting any cutting to root is chancy at best. The plants really do seem to read a whole constellation of conditions. It's never going to be just one thing.

I know ZERO re TX gardening, and I have nothing to cite to back up my hypotheses. But just some possibilities to take into account. Think outside the box, yeah?

Joan

Good point about seed freshness, but this has been going on for several years with different seeds coming from different seed providers. I don't see how germination can depend on daylength. As in, before germination, it's always pretty dark in there!

Dan, the thing about day length though is that it affects soil temps throughout a day. If soil temps are of a certain range for one part of the day, and for less of the next day, and less of the day after that, why, I suspect that's going to be a Signal. That was really the point.

Seeds don't "see" light, or at least some of them don't. But they do feel its effects.

Joan

My day/night temperature range is pretty small, mainly because of my humidity. Right now, I'm seeing 80F/60F. I don't think beet seeds are going to care about either. But it's true, if you live in a very dry place, with wide swings in day/night temperature, it might be significant.

It is true that, in principle, soil temperature can be significantly higher than air temperature if the soil is in full sun. People doing tests on best germination temperature don't seem to make a big deal of that, however.

That all being said, I really don't understand how high temperature can affect germination RATE. As in "ouch, it's so hot, I'm gonna go slow!" I can understand how it could prevent germination entirely, though.

Good luck, Dan. As I said, my environment differs from yours, but I've definitely noticed day length making a difference here. And to reiterate, I think it's not so much the temp range, but the direction of the temp range, that I think may be an influencing factor. I'll keep any eye on this thread and see if if anybody comes up with an answer for you. Meanwhile, I've offered my best hypothesis.

Joan

Again, re heat and germination rate, with regard to vegetation (and bacteria and fungi as well) heat makes things go FASTER, until it kills them. My guess is that if you plotted germination rate versus temperature for anything, it would increase. In fact, to the extent that beet germination depends on physical scarification by soil processes, that will go faster with warmer soil too. So I can understand how heat would prevent germination entirely, but not how it would slow it down.

Maybe someone can come up with a horticultural argument against this? Does anything grow slower as it gets hotter?

Whoops, Dan, I may have misunderstood your circumstances. I have been assuming that since the solstice, day length has been decreasing, and that therefore that signal has been given to the seeds on each day since then, and at an increasing rate since about the 1/4th mark to the 3/4 mark; so I've been assuming that since the solstice has passed, your soil temps must be decreasing, even if only marginally so, since you garden in the Northern Hemisphere.

As I said, I know nothing about the soil temp curve in TX through the course of a year. I would *never* argue that germination/production are better when soil temps are declining, except in the case of certain species. Sheesh. I'm checking out. Best luck getting an explanation!

J

Well NUTS!

I've been planting a row of beets every few weeks. They'd been coming up in 2-4 weeks. I thought I had proven definitively that this 5-10 day germination time that is claimed by some was totally bogus. I just planted another row five days ago, and they are starting to appear! Huh???? As a result of my warm weather, my soil temp is now a little higher than normal. As of today it's 78F (as per Greencast/Syngenta), while it was 70-75F earlier.

Now, here's a clue. My earlier plantings were Burpee's Golden (for which Seed Savers give 5-10 days germination), and this last row was Early Wonder (for which Burpee says 14-21 days germination). So I have to conclude that the beet varietal makes a BIG difference in germination time, and there is some confusion about what does what.

That all being said, I'm pretty sure I've planted Early Wonder in previous years and never saw a short germination time with them. Oh well.

Now, I really don't care all that much about what the germination time is, except that it would be nice to know what to expect, so one knows when and if one has to replant.

May be those seeds like to have a special day/night T difference.

To scarify without using sharp tools on small seeds between your fingertips, I've use the sandpaper method and it seems to do okay. Wrap sandpaper facing inwards in a jar, put the seeds in, and shake them vigorously for a while.

Maybe fully pregerminating would lead to broken tender little roots, but I do like to soak some types of seeds overnight or longer before planting. Or if you soak them for a few days in damp paper towels in a warm place after an initial overnight submerged, it might help you at least cut a couple days off.

With regard to letting the beet seeds sit in water until they germinate, and then planting them, root damage is one of the last things I would worry about. When I plant 2 inches apart, and they come up anywhere from 2 to 6 inches apart (because of incomplete germination), I routinely restore 4 inch spacing by transplanting the seedlings, and even shaving multiple seedlings (as beets tend to produce) apart. Movin' them around. A small teaspoon does a nice job of that. They all go on to thrive. I find that tiny beet seedlings are pretty indestructable.

As I think I said, I have soaked my beet seeds overnight, and it seems to make little difference in germination time. Wet seeds are harder to manipulate, however, and I don't enjoy planting them. You can't easily drop them in place. They stick to your fingers. So especially in that soaking doesn't seem to make a big difference, I'm inclined not to soak.

I'm skeptical about beet seed scarification by shaking onto sandpaper. I've done this, and they come out looking pretty much the same, with little or no chaff left behind. I think they are too lightweight to scarify efficiently by bouncing them around. Heavier seeds scarify a lot better that way.

As of now, as usual, I have thirty feet of beet seedlings, perfectly spaced. It just takes a LONG TIME to make that so.

Watching this thread For ‘the answer’. I get a kick out of it because my childhood seeding experience with beets (in mountain zone 3) was, generally up with the rest of the garden in a week. Now in a humid zone 7, it’s is the same as Daninthedirt’s: Sow. re-sow. Soak, re-sow. try another variety. Sow. Scratch head. Then all grow. Majorly thin rows. I don’t know. I had thought it was me. Or the seed.

Now I know I’m not crazy. It’s nice to feel vindicated. But it’s just an example of gardening: we go along, thinking we know, and when an element of the equation changes, we find out we don’t know so much, and are a bit humbled by the mystery. I’m leaning to the side of the soil temperature and variations team. But- I don’t know.

OzarkHeather, you're absolutely right. That was also my experience back in Zone 7 (Mid-Atlantic). I was sowing and re-sowing... It's even worse now in Zone 9, especially in the fall when the air temps are perfect, but the soil is still very warm. That combined with days getting shorter... ugh.

The only thing that germinated for me nicely this fall was Swiss chard. The rest was a real struggle to get going -- it took weeks of re-sowing. BUT, I did a "control group" indoors under lights, and every single seed came up within a week...

I'll add to the mysteries of slow beets that I started this thread about. I now have full rows of sprouted beets. Finally, and as usual. But once finally germinated, the beet seedlings grow VERY slowly. ALWAYS. I've seen hair-pulling about this several times in this forum. My beets finally sprouted a month or so ago, and they are barely an inch tall now. (On the other hand, I threw down some radish and bok choy seeds this last weekend, and they are already an inch tall!) I'll say it again, and louder. This is NORMAL for me. I am completely confident that in a month or two they will all be going great guns, as they have for me for many years, but it strikes me as kind of strange, as does much of beet germination.

I have the problem of cr*ppy beet germination in the spring but fast, high germination rate in late summer. My money is on soil temps, at least up here, which obviously is completely different than TX. I'm envious you have all those beets! Often a late summer crop won't develop in time up here, it's weather/temperature dependent. Basically it's a crapshoot for me with beets. But I keep trying...sigh...