First time sowing seeds - is it too cold here?

[baps]

Hey folks,

Never planted seeds before. First time planting anything really last year so apologies for the noobishness in advance.

Finally got a greenhouse built and covered with greenhouse plastic. So far so good. Hasn't felt really any warmer in it (need a thermometer) until today, was definitely a few degrees warmer. But this is the first day since I've got it finished that there's been any sun here. I'm in Northern Ireland, which probably has some impact on the question coming shortly.

Ordered some seeds, seeds arrived and the ones that are listed for sowing under glass say sow in April at 16oC or 20oC. So I'm wondering how important that temperature rating is? Anyone that lives here probably knows if it's 16oC in July we're happy. 16oC in April? Notachance! I get the greenhouse will increase temperature, but not if there's no sun surely.

So can anyone suggest if/when I should sow these seeds? I do need a thermometer, but was looking forward to popping them in some trays! Let me know if seed info would help, they mostly seem similar instructions for the greenhouse ones.

Many thanks,

Baps.

[veggiechicken]

It would help if we knew what seeds you have!
Sowing at 16-20 indicates a heated propagator or indoors. Not a greenhouse where the overnight temp drops to single figures and even freezing.

Have a look at the table in https://www.growfruitandveg.co.uk/gr...ion_93787.html and see the impact that different temps have on germination.

[baps]

Thanks veggiechicken, didn't know the temperature had that effect. Didn't really know what the effect was I guess, just didn't want to screw up my first seeds (too much).

Seeds are as follows;

Climbing french beans - 16oC in April
Dwarf french beans - 16oC in April
Asparagus - just says sow in trays in April
Leeks - just says sow under glass from March
Courgettes - 20oC in April
Lettuce - 15-20oC
Strawberries - 16oC
Tomatoes - 18-21oC
Gourds - 16oC from April

There's a few other seeds say sow directly and not under glass.

Baps.

[veggiechicken]

lettuce and leeks may be OK started in the GH. The others I would start indoors - or wait a few weeks until the weather improves.

[baps]

Ok, sweet! Not really sure there is anywhere indoors we can start many seeds. Hence building greenhouse, but yeah, didn't really think that would be needed. I'll see if maybe the dog would share his window with some trays and not nomnomnom them into a pile.

Thanks veggiechicken!

Baps.

[rary]

The sowing guide on seed packets are on the main suitable for the warmer parts of the country, the likes of beans, I sow mid May, if I think its warm enough, any earlier I have problems with space in the greenhouse as they can't go out till after the last frost, and if you sow your seeds indoors you will need move them out to the greenhouse, and there are ways to hold the heat overnight, like using plastic containers painted black, in the greenhouse or simply covering all you plants with fleece till overnight temperatures are warm enough for your plants, and yes a thermometer would be useful if you can afford it buy a max/min thermometer

[nickdub]

Agree with VC on this, though as usual it does depend on the weather which means it could be anything at the moment.

If you are short on space inside and/or money is tight for a large propagator what I do is start the seeds in a plastic box with damp kitchen roll at the bottom which I then put to keep warm in the airing -cupboard . Once the seed shave sprouted they can then be sown in pots or trays. The point of this is that its easier to keep a higher temperature for germination but once that has happened the seeds will grow on at a lower temperature as long as its not too cold.

Obviously handling large seeds is easy enough, so this method should work with all the ones you mention except the Lettuce and Strawberries which are fairly small. I'd put a little compost in a plastic box for those and scatter the seed on the surface with a little water, but not a lot. Germinate in the warm like the others, but put them somewhere light as soon as they show signs of a root starting.

[baps]

Never spotted a max/min thermometer. I'll have to go nosey for such a thing. Also heard a few people mention fleece while searching for my seed-related question so I'll look into what that actually is. Thanks!

I did see some guy on youtube putting seeds on kitchen towel with sugar water but I didn't really grasp in the hell he was doing. That makes a bit more sense now. I take it that's not normally necessary or just a suggestion to combat the temperature problem?

Thanks,

Baps.

[nickdub]

Never spotted a max/min thermometer. I'll have to go nosey for such a thing. Also heard a few people mention fleece while searching for my seed-related question so I'll look into what that actually is.
... . That makes a bit more sense now. I take it that's not normally necessary or just a suggestion to combat the temperature problem?



Baps.

a max/min thermometer does more or less what it says on the tin - its like an ordinary one but with a U bend and little inserts in the mercury column - these stick where they are pushed in place when the temperature changes at the highest and lowest points respectively. I dare say you can get digital one to link to your I-phone now, and certainly they used to make some which you could install so they register a temp simultaneously inside and outside a structure.

horticultural fleece is a filmy type material which lets air and rain through but forms a barrier to insects etc and also helps insulate plants so protecting them on frosty nights.

As for germinating seed inside, that's a bit more complicated. Roughly speaking its easier to achieve the consistent high temperature required by seeds like tomatoes if you have them in a box in your cupboard than it would be if they were just in trays outside somewhere. It also means that the seeds and seedlings are not going to be eaten straight away by something - mice can run through a whole row of pea-seeds in a night. As against this handling tiny seeds, especially when they have a v delicate root is a bit of a faff.

Probably best to ask again if you have some seeds you are unsure about.

[baps]

Yeah I see a load of those thermometers and they're not too pricey. I'll grab one of those, thanks.

In all likelihood I'll be back with more seedy questions. Have a bunch more listed only as plant straight outside, so probably need to be thinking when on those again. One seed at a time though!

Baps.

[nickdub]

No worries - enjoy your gardening.

I always marvel at seeds, they're minor miracles really when you think all the info like plant details of shape, taste, colour, size etc all coded in to that tiny package, which can stay dormant for many years sometimes, yet still have the germ of life in it.

[Bacchus]

Hi Baps, lots of great information from all above.

There are a few of us NI folks on here too. I've noticed that where I live it tends to be a couple of degrees below what the forcasts says the average temperature is going to be - just a quirk of the local geography - but that does impact on things significiantly when it's around frost temperature or not frost temperature.

In this locality, as a general rule of thumb I would err on the latter side of any suggested growing window for UK orientated seed packets. However, with the benefit of a polytunnel - or greenhouse in your case - you can add a few degrees to the average temperature but watch out for sharp frosts as it's they that seem to do all the damage and they will penetrate plastic or glass easily to get at those susceptible seedlings.

If you're just starting don't worry about a few mishaps in the first couple of years - it will likely take that long for you to work out what exactly how your local geography affects what grows well and what doesn't and how frosts linger or how sharp they are specificially where you are. Generally speaking, seeds are quite cheap (or free with some magazines) so don't be afraid to do a bit of trial and error.

Best of luck...

[muck lover]

Good luck with your seed sowing.
Mostly if you delay for warmer weather the seedlings will catch up especially with the lengthening days. Earliness isn’t everything.
And if all else fails get plants from a friend or.......... buy some baby plants and get growing!

[baps]

In this locality, as a general rule of thumb I would err on the latter side of any suggested growing window for UK orientated seed packets. However, with the benefit of a polytunnel - or greenhouse in your case - you can add a few degrees to the average temperature but watch out for sharp frosts as it's they that seem to do all the damage and they will penetrate plastic or glass easily to get at those susceptible seedlings.

Thanks Bacchus, that's helpful. Have went and got shelving the dog can't get at, so I guess if I keep an eye on the weather I can bring those inside.

Good luck with your seed sowing.
Mostly if you delay for warmer weather the seedlings will catch up especially with the lengthening days. Earliness isn’t everything.
And if all else fails get plants from a friend or.......... buy some baby plants and get growing!

That's what we did last year. With getting the ground cleared and ready to plant in, didn't want to try seeds etc. as well. That just sounded like a recipe for disaster. Buying baby plants from a nursery ended up quite expensive though. Greenhouse materials cost less than plants from the nursery did last year. So I'll give it a go! I do think perhaps the neighbours trees may be having more of an impact than I thought they would, so the whole endeavor might be limited if we can't convince them to chop them. Will see though.

Figure we'll make plenty of mistakes. Just trying to avoid the avoidable mistakes by bugging you guys for advice.

Baps.

[It never rains..it pours]

I do think perhaps the neighbours trees may be having more of an impact than I thought they would, so the whole endeavor might be limited if we can't convince them to chop them. Will see though.
Baps.

Have a similar issue growing here with neighbours Leylandi's, great as wind break but now too tall. Please let us know what works best with neighbours

https://www.rhs.org.uk/advice/profile?pid=408