EP336- One Problem Three Solutions: Why Seeds Fail After Germination.

This weeks sponsor: 

Crann From  Probio Carbon 

https://www.probiocarbon.ie

Your seeds are not “mysteriously bad” overnight. When carrots, peas, and lettuce fail again and again, the real culprit is usually the same thing we have all been living through: wild swings in soil temperature and moisture, plus bursts of intense sun followed by heavy rain. We break down what those swings do at the exact moment seeds try to germinate, and why the first few days after emergence are the most vulnerable stage of the entire growing season. 

We get specific about the tricky crops. Carrots can sit in cold, wet ground and do nothing, or they can germinate and then vanish when the surface dries before roots establish. Lettuce brings a different problem: once temperatures climb above around 20°C, lettuce seed may refuse to germinate at all, especially in a polytunnel or greenhouse that can hit extreme heat. We also talk about the frustrating stuff that looks like a germination failure but is actually slug and snail damage, plus why seed quality is worth considering even if it is not the most likely cause. 

Then we lay out a simple, practical rescue plan to save your season and avoid a harvest gap: sow peas and lettuce in trays and in the ground for a staggered backup, manage heat with shade during germination, keep compost evenly moist with quick daily checks, and use plug plants strategically to bridge missing weeks (with a clear warning on carrot plugs). If you have been doubting yourself, this is your reminder that even seasoned growers get failures, and the best growers adapt to what their own garden is doing. 

Subscribe for more practical vegetable gardening advice, share this with a friend who is re-sowing for the third time, and leave a review so more growers can find the show. What crop is giving you the most trouble right now?

Transcript

Listener Question And The Stakes

SPEAKER_00 0:12

How's it going everybody and welcome to episode 336 of Master McGarden Podcast? Now, this week's episode is it's answering a listener's question, and it's one that I know is coming up for a lot of people because I've seen it in uh the gardening Facebook groups, several people asking or querying the same thing. And essentially, this listener has been growing uh vegetables for a number of years, has never had any problem previously, has been relatively successful with crops, but this year she's having fails and in sowing up seed. And there's three in particular that she's having problems with one is carrots, one is peas, and one and the other is lettuce. And as I say, this is quite a common tread at the moment because I can see other people are having the same issue, and there's probably a couple of potential reasons, but I'm pretty sure that the one reason is you know what we've spoken about before in the variability in temperatures and so on. So we're going to chat about that. We're going to give this problem a solution. Hopefully, you know, we can still salvage these crops uh or have harvests coming along. So that's that's the you know, that's the context of of this episode.

Sponsor Message On Strong Seedlings

SPEAKER_00 1:35

Um before we get to that, a message from this week's sponsor, and it's quite relevant when it comes to what we're talking about, is seed sowing. And this week's sponsor is Crayon from Probiocarbon, and the you know, the the context of it is it starts with the soil, the familiar ground of Irish farms, shaped by rain seasons and time. From probiocarbon comes crayon and probiocarbon biochar, both of which you've talked heard me talking about before. Crayon is applied at the earliest stage, helping seedlings settled in and begin building strong, steady roots. And around those roots, the sign biology is encouraged to become more active and more balanced. A key part of that biology is the use of Irish microbial isolates, selected and adapted specifically for Irish soils, these microbes already suited the local conditions, working in step with the ground rather than against this. The biochar then supports the living system beneath, so it becomes like a home for the microbes, helping it to hold moisture in wet times, uh, or helping it to hold moisture through dry spells and giving it giving the microbial communities a space to live in. So you've heard me mention before it's like a hotel for the microbes. As the crop grows, the early foundation often shows through with steadier plants, better able to cope with disease pressure and the changing Irish climate again, uh, and the change changing Irish weather again, that's very relevant at the moment, and makes the crop even stronger, bringing healthier, uh, more abundant harvests. So it's a simple idea, work with the soil using biology suited to Irish conditions. And for all information on the products, check out www.probiocarbon.ie. And that is, as I say, relevant to this week's episode and supporting you know seedlings.

Cold Wet Ground And False Starts

SPEAKER_00 3:22

So this listener basically what's happening is sowing seeds, failing, tried a second time, failed, and is wondering why. And I guess, you know, over the last couple of weeks, I probably have you know covered this to in certain ways, but we really need to, you know, we do our seed sowing guide at the start of even month, and that is that is a guide of what potentially can be sowed in that month, and but it doesn't mean that we always have to sew or we always should sew or that the conditions are perfect, and at the moment conditions are still um less than ideal. So in the last week we've had some beautiful warm weather and lovely days, and everything is growing really, really, really well. But I can understand why people are having some fails with seed because this person has set the seed twice. So if you think think back more than a week. So this is you know, as we head for the middle of July, middle of June, uh third week of June, thereabouts. And over the last few weeks, it has got you know warm, temperatures have come up, but prior to that it was very, very cold and very, very wet. But we also had these real intense periods of sun. So, for several reasons, your germination may not have happened because of cold ground, because the ground was so cold and so wet, and that was literally the case here in Ireland up until a couple of weeks ago. However, it's not the case everywhere across the country. So, this is what I'm saying to you, you know, in relation to the seed sowing guides, in relation to uh knowing your area, it's hugely important to know and to feel what is happening in your garden, you know, not what's been written on uh a a book telling you what to sew, what I'm telling you at the start of the month is possible to sew. It's to know what is what works for your garden, what's right for your garden at that particular time. An example of that, I have carrots in the poly tunnel which I'm harvesting at the moment, but I have not sewed until last Saturday, which is again the middle of June roughly. I've not sewed any carrots outside. That's quite late for me, so I would normally have that done, you know, a month earlier. But the ground conditions were cold, um it was quite wet at times, it was dry, you know, very dry for a few days, but it just the conditions just never were felt right. So last Saturday uh I saw carrots, I saw parsnips, it was a lovely dry day here, but there was a nice bit of moisture in the ground, the soil temperatures felt warm. When I put my hand on the ground, there was a warmth to it. Whereas the previous week, if I'd done that, it was cold, you know, or ten days before it was cold. The ground felt cold, and as a result of that, you just I wouldn't sow. So the back of the packs, the books, the podcasts, whoever you're listening to, will tell you this is the period of time we can sow. But it's so so important that we understand, and you you will understand it, just use your own intuition. Uh, what seeds want is a nice warm soil temperature, they want adequate moisture, and this is really important. That's the next bit I'm going to come on to. They want adequate adequate moisture, and once they have those things, they will germinate. That's point one. Point two then is supporting them afterwards. So if you take carrots as the example, so this cut this listener has sold carrots twice now and they've failed twice. There's two potential things that have happened here. If you sold them a month ago, for example, it was too cold, you probably would not have got germination, or if you did, it would have been sporadic because the ground just wasn't warm enough there. Then if you if you fast forwarded a couple of weeks, we got that really warm week, really dry week. You may have got germination uh outside, but potentially very, very quickly after germination, if you can remember, a seedling pushes out its you know first couple of leaves of almost no root. It's it's very vulnerable in those first few days, you know, for drying up. So if you sow them at the start of that dry, really dry week, you may have got germination, and then two or three days of that really intense heat, and now your your seedlings are burnt, you know, basically gone. Uh so I can understand why carrots, particularly, people have struggled with. You know, people are finding these issues with it. They've never had it before, you know, they've sold before and it has always worked. But this year is definitely trickier. You talk to anybody who's growing vegetables, it's trickier. So that's the reason for it.

Extreme Microclimates And Sudden Downpours

SPEAKER_00 8:36

It's that huge ups and downs in temperature. Um, you know, high temperatures, low temperatures, heavy, intense sun, followed by heavy rain. And a real brilliant example of it this week, I was talking to a friend of mine at a match the other evening, and he lives as the crow flies, six hundred metres between his parents' house and his own and his own house, and in between those two houses, again as the crow flies, there was a field of hay which was on the point of being ready. And this fellow was coming home from work and it was lashing rain, horrendous rain. Wipers could hardly keep it off the car is how he described it. Drove to his own house, went inside, rang up to the parents' house and was talking to his dad and said that uh you know the field of hay is going to be destroyed now with that rain, and the dad says why? Because it wasn't raining there. So 600 metres apart, and there was you know there was this uh downpour uh in one spot and six hundred meters away, no rain. Like explain that. So you have these variances, and you know, you might you might be growing carrots and everything is fine, or you might need moisture and you get it, you get too much of it in in two minutes, you know. Again, something like that, that real heavy downpour if you got it, your sort of seedlings that have just burst the soil, this really heavy downpour hits them, they can get washed around, they can get you know uh damaged in the ground. So there's there's loads of reasons.

Lettuce Heat Limits Slugs And Seed Quality

SPEAKER_00 10:24

Soil temperatures, as I mentioned, that's another one. Um lettuce, particularly. So somebody is sowing lettuce seed in a polytunnel, once temperatures go above 20 degrees, lettuce will not germinate, it'll just sit. So that's another potential reason because we did have and we have had, even though we've had soil temperatures quite cold, we've had these temperatures in tunnels of up to 40 degrees. Lettuce will not germinate in that temperature. If it has germinated, if it has set its set down its root, if it has put on a couple of leaves, it'll grow actually quite well inside in the tunnel. But that germination piece, if it's above 20, it won't germinate. So if you sow your seeds and it gets that intense heat, it won't germinate. Um if it has germinated and it you miss watering for half a day, it's burnt. So you you know, I there's so many reasons why this person has may have struggled this year. Uh the final thing, which again we've covered a couple of weeks ago, is young seedlings, especially lettuce, if you're direct sawing them into the ground outside, again, after they've just put out the little first um the first little leaf on it, if you get a slug or a snail, they'll just harvest that off at the at the ground. And you know, if you're not vigilant and looking every day, today you could have a line of nicely germinated tiny lettuce plants ready to start growing, and then slugs and snails find them and go back to the next day and there's nothing there, and you're wondering, did they germinate at all? So just when you sow, check every day and you know, be vigilant of it, especially in those first, in that really early stage, because that's where you that's where you can, you know, um I suppose have germination but then lose the plant, and then you're wondering what went on. Final thing, just seed quality, just be careful of that. If it is, you know, failing multiple times, it's highly unlikely because it sounds like you know this person has relatively good experience, so they're using relatively, I'm assuming relatively good seed. Just watch for that. Uh, it could be a factor, but highly unlikely. My instinct says that it's all to do with these fluctuations, huge fluctuations, and they are definitely causing problems for people germinating seed. It has been without doubt the trickiest, the trickiest uh spring that I've seen for a good while. And we've had some funny weather over the last four or five years, but this is a tricky, tricky time. Uh having said that, anything that is growing now, you know, that you've got past germination state, is growing really, really well. The growth is there, the moisture is there, the temperature is there. So everything is hunky-dory from that side, but these little glitches at the seed sowing stage. So hopefully we'll be able to give the solution now as well.

A Practical Plan To Salvage Crops

SPEAKER_00 13:21

So the problem, I suppose, off the back of these failed germinations is potentially a harvest gap just down the line. And if you don't have these, you know, these uh plants now ready to go, you potentially, as I say, have a harvest gap coming because you know you may have, like, for example, my carrots. Because I'm about a month later sewing the carrots outside, I'm definitely going to be finished the indoor tunnel carrots before the outdoor ones are ready. So I'm gonna have a sewing gap there, and that happens, and it's no big deal. Um, ideally, I'd like to have them continuously, but it's not gonna happen now. So the carrots from the tunnel will be finished, and then the outside ones won't be ready uh on top, you know, in to to sort of coin coin or um coordinate with the end of the of the tunnel harvest. So you can you can see that there's going to be a little bit of gap there. But as I say, that's no no big deal. Um, what this person can do in this scenario is get some plug plants. Um while you might not do that on a regular basis, it'll just give you that, you know, you'll have strong plants going in and they will bridge the gap. Um they will bridge the gap of that harvest or though of those seeds that didn't germinate. So you'll get your harvest where otherwise you would have missed it. Um sow seeds in the tray now. So in a tray, your peas in your your peas and your lettuce. Um I'm going to come on to carrots in a minute separately. So peas and lettuce, sow them now in trays, but also sow them in the ground outside. And what's likely to happen if you have a greenhouse or whatever, sow your seeds in the tray in there, watch for the temperature as I mentioned on lettuce. So if it's really, really hot, uh put put shade over them or germinate them, you know, in a in a shaded spot so that that they're that bit sheltered, they don't get too hot, and you get the germination. Once they're germinated and the leaves are on them, then they'll grow away fine. But what that'll give you is a slightly staggered germination because the tunnel, the tunnel or the greenhouse is likely to be a little bit faster than what you put in the ground outside. And then when I go to say is be very vigilant. So after sowing, check them every you know, from the first time from the first day of sowing, check them every day. Because again, in the tunnel you could sow your seed, water the tray, and if you don't go back to check that by the tomorrow evening with the you know the types of sunshine we're having, that tray is likely to be very dried out. Your your seed will be dried out, and and you know, it just won't it won't germinate. So a little sprinkle of water, make sure that the compost remains moist, not in too warm of a spot. They will be faster than what you put into the ground, but put some into the ground at the same time, out in the ground, be ultra vigilant once you get germination, uh, to ensure that you watch out for slugs and snails, be very vigilant, check them every couple of days. Once they're up and running, once they're up to you know, a couple of um couple of true leaves, they're starting to put on a bit of shape, then you can be less, you know, you don't have to be molycodling them as much, but at the at those first couple of weeks, just watch them regularly. Not talking about spending a lot of time doing it, but just vigilance and watching for that. Carrots outside now, um I'm I'm saying buy plug plants and that'll help you bridge the gap. I in the springtime was doing a demo uh for a company on growing vegetables, and I used some I sold carrots into a into a pot and in the centre I put some carrot plugs that I bought. And it's not something I would ever do, but I wanted to do it for the purpose of the demonstration. And just for reference, I would never use carrots that come from a plug plant that you'd buy in your garden centre because and I knew it, but they don't grow successfully, they they they're bunched too tightly together, they end up being basically when I'm harvesting them now, they're in a bunch, they're all wrapped around each other, hugging each other, and there's none of them any longer than your little finger. And they're really small, but they're butty, they're intertwined, so they don't form proper carrots, and I've found that before. So that's the one crop where your you know your tree, your peas, your lettuce, your carrots failed. I would buy plug plants on two peas and lettuce, but not carrots. Um they're still edible, they still taste quite good, but they're they're not what I would call a true carrot. And I only I only bought them for the purpose of the demo. Um, but generally speaking, I wouldn't do that. So anyway, to sew your carrots now. As I say, I only saw mine last Saturday. It was a lovely warm day here. There was a nice bit of moisture in the ground. Um it has been a warm week with little bits of little bits of rain here and there. So that ground, and I've checked them since no germination yet. There is moisture there still. The ground is still quite warm, they're definitely going to germinate, and they'll germinate well over the next over the next week, I hope. Um but once they're germinating, once I see that little green fleck coming up through the ground, I'm watching them every day for the next week or two that we don't get that top inch drying out. Just keep a little bit of moisture, it doesn't take a lot, a little bit of moisture to ensure that they don't. So the solution to your problem, sow some seeds in the tray, so some seeds in the ground, buy some plug plants to to plug the gap, and then don't forget to sow again in a couple of weeks' time. It'll be getting late for carrots, but you might be able to get a you know a sewing done in a in a few weeks' time of a small carrot, like a bunching carrot, and that'll kind of bridge the gap and maybe make up for the for the missed sewings or the the failed sewings of earlier time. The other

Why Failures Happen Even To Pros

SPEAKER_00 19:45

thing to be really um aware of is that this can happen, you know, regular every year, no matter how good of a grower you are, whether you're per you know a large scale professional grower, whether you're an amateur grower, whether you're doing it for the first time, whether you're doing it every year for 20 years, something every single year will be a fail. And you know, it can be it can be one thing one year and something different the next year, and that's that's perfectly normal. And I wouldn't worry about it. Um it's it's learning, so you'll you'll pick up something. So, for example, in your scenario, your carrots have failed. Likely what has happened is they have either gone into ground that was too wet in the initial sewing, and possibly in the second sewing, got dried out after germination in the first day or two. So once you know that, then for next year, like you could have sowed before, and just there was enough of moisture, there was enough of heat, things were fine, and they germinate and they grow. But then it is just so variable at the moment, and that's why you know somebody with relatively good experience is having these little fails now. Um, but it isn't it isn't anything to worry about, it's not you know, these things happen, they're little learning opportunities. Um for me, onions in the tunnel have always been successful. Um, this time a good few of them have gone to seed because of the mad temperatures a few weeks ago. Um, when I put the video up on Instagram about it, I had some lovely uh people telling me that it makes no sense to put um onions in a polytunnel, that they should never be planted in the polytunnel, and yeah, people seem to know very, very well. However, for the last ten years I've been growing onions in the polytunnel. Every year I get a really early harvest from it. This year it just so happens that some of them have gone to seed because of that mad temperature, but I still got a decent harvest. So don't mind what everyone is telling you. What works in your garden is what works for you. So that's the important kind of takeaway, I hope, from that.

Upcoming Guests Thanks And Wrap

SPEAKER_00 22:01

Um couple of guest interviews. I kind of hadn't as many guest interviews over the springtime, um, not by design, just kind of happened that way. Um, probably wasn't outreaching at all. Um, and I'm not sure why. Wasn't any particular reason. So I'm getting back to some guest interviews over the next couple of weeks as well. And uh, yeah, there's some interesting ones coming up. Um, we're going across the water again in the couple of in in the coming weeks over to the US for really interesting interview there. So, yeah, lots of guest interviews coming up and all the usual all the usual episodes as well. So before we finish off, a big thanks to this week's sponsor. It's Probiocarbon. You can check out their website. Uh the website addresses in the show notes. And uh, yeah, that's been this week's episode. Hope your seed sewing can get back on track after that. Hope it helps. Any other listeners who have any gardening questions, shoot them across and uh happy to answer you know any kind of small problems like that that can help help help help people in their own gardens. So that's been this week's episode. Thanks for listening, and until the next time, happy garden.