We’ve had so many folks contact us this month asking what they can grow now in their greenhouse or if they can sow certain seeds. And you know what, I’m not surprised by all the confusion out there because it feels like everywhere you look, folk are planting things or showing off their seedlings or telling you to plant now to get ahead of the season. So let’s talk about this so that you guys can develop a bit of a better understanding about how things work and then you can make decisions for yourself, instead of letting folk online (like me) tell you what to do.
What can I sow this month?
Well, that all depends…seeds need warm soil and moisture to germinate. Then seedlings need warmth and strong, direct light to thrive. So does that sound like your garden right now? If it does then you can sow.
If you live further south you can generally plant sooner but if you live further north, like me, you have to wait – why, well because right now, our garden and importantly the soil is really cold (think minus 6 celsius) and more importantly very frosty – hence my penchant for woollens.
Frost can kill the little seedlings when they emerge and we are still getting a lot of frosts. That’s basically it in a nutshell, but maybe we should look at this in a bit more detail.
So here are all the things you need to know about to make a decision on planting and sowing at this time of year.
- your frost dates
- your average weather
- what environment your plants want
We all know winter is cold, right? And we all pretty much know that we can’t just put seeds or seedlings into the ground outside when the weather is really cold. But It’s not the snow and general cold we need to think about when we start to think about getting ready for spring, it’s frost.
Frost will most likely kill young seedlings, so you don’t want to be planting anything outside if you know there is a chance of frost that could kill them or even badly damage them. Thing is though, do you actually know if it’s likely to be frosty overnight? I’m asking in all seriousness because we often assuming that oh it’s not winter anymore and it’s warmer during the day so we don’t get frost, but that’s not actually true. Here in East Lothian, we can still be getting the odd frosts overnight in May. So it’s good to know for certain when you are likely to see frosts and when they may stop. We refer to this as your final frost date.
For me, my final frost date is around the 16th of May. I say around because obviously, this is the weather we’re talking about, it could be a couple of weeks either side of that, but just knowing that it’s around then means I know that it’s not a good idea to put seedlings out before then. My first frost date (first time we see frost in Autumn is around the 21st October, but we’ll talk more about that in a second.
You can find out your rough frost dates from this really handy website: https://www.gardenfocused.co.uk/
So, now we know when we can sow our seeds or plant our seedlings outdoors – Yay! But let me ask you, is there enough time left now for your little plants to grow big and strong and for them to produce fruit (peppers/tomatoes etc) and for the fruit to ripen?
This is where your first frost date comes in. Let me explain. So my last frost date is around 16th of May. My first frost date is around the 21st October. So between those 2 dates is roughly the length of my growing season. So I need to know how long that season is so I know if there is enough time for my plants to go through their full growing spectrum.
So count the days between your last frost date and your first and that’s your growing season. Well sort of. So I know that between those two frost dates is 157 days which technically is my season, but remembering frost dates can vary by a couple of weeks and I also know that there can be a few days at either side that also aren’t great for growing, so I take that into account. So if I say there are a few weeks either side of the season that aren’t guaranteed, accounting for moving frost dates and poorer weather, let’s say that’s 60 days in total. So I take that 60 days away that leaves a realistic season of around 97 days.
So step one, look up your frost dates for your area and work out what you think your initial growing season might be. And think about your general weather, either side of those dates, would you subtract any days that are potentially going to be too cold for the plants?
So there we go then, we have the first part of our equation, our growing season. If your growing season has started, in other words, your last frost date has passed, then you very well might be able to sow or plant in your garden just now. For me though, I have to wait a few months before I can realistically put new seedlings into the garden.
What are you planing to grow?
Now the next thing to think about is what you are planting. Different crops need different lengths of growing season and obviously different amounts of light and heat. This is fine for what we call cool-season crops like salads, peas and beans or even root veg like carrots. These are crops that don’t mind the cooler weather and grow and thrive with no issues, but for warm-weather crops like tomatoes or sweet peppers and chillies, these can require a much longer season and a season with more of the warmer days. So for these crops, things are very tight for me. These, warm weather crops, need a lot more light and heat than my season gives.
For example, peppers need a fairly long growing season (around 90 days of perfect warmth and light). So if I have 97 days of growing season, I should be able to grow pepper plants. And as you guys have seen, I do and I’ve had decent success with them. However, I have success with them because I cheat.
Extending your season
So one of the things we can do to cheat mother nature here is to extend our season artificially.
So luckily I have a greenhouse. This helps to extend my growing season because once we do see the nicer weather, the greenhouse gets warmer than the temperature of the garden and so provides the light and warmth the peppers and tomatoes need. But, my greenhouse is unheated, so it can’t really offer this type of warmth until the weather improves and we start to see more warm, sunny days in the garden. However at the other end of the season towards autumn, my greenhouse stays warmer when the weather in the garden is getting cooler, so I usually have a couple of weeks of extra ripening and harvesting time just because the plants are in the greenhouse.
So right now then, at the start of the year while we are waiting for spring, the greenhouse is cold (this morning it was minus 5C in there. As you can imagine, this means I can’t sow pepper and tomato seeds in the greenhouse and expect them to germinate. It’s just far too cold. This is why you usually don’t hear about me planting my seeds until much later, usually March. But…. the big excitement in Ar Bruidair this year is that we are cheating mother nature again. This year, for the first time, we are sowing our pepper seeds now!! We have set up a new “germination station” in the house. Can you feel the excitement?
Sowing seeds indoors
Phew, that is an awful lot of info so far, but bear with me, this bit is important for anyone thinking of sowing their seeds indoors to get them to germinate.
So firstly… yup, you absolutely can sow your seeds indoors where it is much warmer and get your season off to an early start, in fact, that’s probably what you are seeing happening on all the social media channels right now. But before you rush off to grab your seedbox and some potting soil, there is one more thing to think about, not just if you can provide the heat needed… it’s light.
Let’s talk about window ledges.
So for a whole load of us, we sow our seeds indoors (for the warmth) and then put those seedlings onto the brightest window ledge in the house to give them as much light as we can – hurrah, but… sorry there is a but…. you might actually find that your window ledge doesn’t give your little babies what they need.
Have you ever noticed that your seedlings grow leaning to one side – the side where the sunlight is coming in? Unfortunately this is a sign that they are struggling to get the light they need, they lean to try to get more of it. Now, I know what happens when we see this, because I’ve done it, we turn the pot or tray around and our little guys straighten up. Well unfortunately this doesn’t actually fix the problem, in fact it can actually make things worse. The reason they are leaning is because they aren’t getting the light they need. Seedlings need intense, direct light. Way more than we probably realise. This act of them leaning to one side is actually damaging to the seedlings and it stretches them out making them weaker. We call this leggy, often when we see the seedlings become elongated because of the process of continually stretching out one way or the other to reach for the light.
This is why I previously gave up on trying to grow my seedlings indoors. I just produced really leggy seedlings that either didn’t survive once they were transplanted or took forever to get their health back and never really produced as adult plants.
But… this year I’ve bought some lights. Hurrah.
So now I have my little germination station which has my seed trays on a temperature-controlled mat providing the heat that the soil needs to help the seeds germinate and I have some strong grow lights directly above the trays to provide direct intense light. So I’m very hopeful that this year I will get an early crop of strong pepper and tomato plants to move out to the greenhouse once the weather warms up.
Oh and just on that point, if you are planning on starting your seeds indoors, light is something to think about seriously, because you may have space and heat for a tray of seedlings, but you need to keep those little guys indoors as they grow and become plants until it’s safe for them to go out to their “forever home”. Do you have the space, heat and light for those 30 tomato plants you just started?
So before you jump in copying your favourite social media influencer (which I hope is me), make a cuppa, grab a biscuit and assess the situation. Can you provide the perfect home for all those little plants?
See my germination station in action in this weeks video and let us know how you get on 😀