Help please. Petunias and grow lights

Hi Everyone,

It's been a while since I've been here due to illness, but I feel well enough to try some gardening again this year.

Last year I saved all my seeds from my hanging basket petunias and climbing petunias. In the past when I have tried to grow from seed they have been straggly and slow growing and I have lost at least half of them, due to the fact that very little light seems to come into the house during the winter.

So this year I have bought a wilko mini greenhouse and a sun blaster grow light. The only space I have for this is against a wall in my living room. What I'm looking for here is some clarification of the instructions I've found for raising the best petunias....

(1) The instructions say to place the newly sown seed trays into good light but not direct sunlight. As I get very little light in the house (often have to have lights on in the middle of the day during the winter months) would it be ok to put the seed trays directly under the grow light or does this count as direct sunlight? If I can't put them under the grow light what do I do?

(2) I intend to start the seeds off on a propagator mat and just leave them in the living room on the mini greenhouse once they sprout. I normally have the heating on at 20 degrees and wonder if this is an OK temperature for the room?

(3) The grow light has two little holes at the top so that you can suspend it above the plants. I was wondering if garden twine/string would be OK or do I need to use something stronger? And does anyone know any good knots that are easy to do and undo as I have arthritis in my hands?

(4) I'm not sure how long I'm supposed to keep the plants under grow lights. The instructions I found say petunias need 10 weeks from seed so I was intending to start them around 20th Feb and to get them into the garden for the 1st May (usually past last frost dates by then). But do the plants stay under the grow lights for the whole 10 weeks or come off some time before then?

I really would appreciate any help or instructions that you can give me to chance of actually being able to grow some decent plants for a change.

 

Which grow light have you got? I Googled sun blaster and it is a whole range, from feeble little lights to artificial suns. How you use it depends which one you have.

 

Hi Clueless,
Thanks for responding. The grow light is the SunBlaster T5 Nanotech Reflector Combo as shown below

SunBlaster T5 Nanotech Reflector Combo 90cm (36 Inch)

 

I'm guessing it has similar light output to my LED one. That being the case, it is nowhere near the equivalent to full sun. More like a spring morning when very close to the seedlings.

I've never grown petunias from seed, but in general terms, I'd want it as close as possible to the seedlings, ideally a few centimetres above them. I'd give them 8 hours per day minimum. I don't know if heat is an issue. Yours is different technology to mine. Mine emits no hear at all. Yours might, in which case you'll need to be careful not to burn anything. When I use my grow light, I let the seedlings have it as soon as they poke through. That way they don't grow leggy searching for light.

Again in general terms, I find that once the seedlings are young plants, they need more light than mine can give them, but it's not usually a problem because by then it's usually early spring, so I can start putting them outside during the day.

 

Hi Clueless,
Again, thanks for responding. I know nothing about growing under lights and I guess I should have asked advice first but sigh 'tis too late now. I will let you know once I start using them whether they give off heat or not.

It seems from your response that I should keep them under lights until the weather is fine enough to put them outside.

I do intend to get more lights as funds allow so I would appreciate advise as to which ones to get and where from.

 

Hi Auntpol , I think you set up will be fine in a room at 20°c . Light is a problem for us all , so I start the majority of my seeds in early March. If you are having problems growing from seed . I would ignore your collected ones for this year and buy some packet seeds from Wilkos or similar and follow the instructions ! You start the seeds off in little propagators like this using a good seed compost on sale at Wilkos . You can easily make your own seed props from food trays . Make sure your seed compost is just wet ( It holds together but no water drips out when you squeeze it ) I water my seed compost before I fill the trays to make sure it is just wet

 

Hi Harry,
I have all my propagators with lids from a couple of years ago and I usually do buy seeds from wilkos or online. I just thought I would try this year with collecting the ones from the plants I loved last year. I honestly do think that my big problem is light - I generally lose 50% and started buying plug plants instead for a couple of years, but would now like to try again and hence the buying of a light and all the questions. Like I said to clueless, I now realise I should have asked the questions before buying the light.

 

I think you've done alright. I reckon your light will be fine as a starter kit. I only have a 1ft square LED array. With our setups, we're hardly likely to gain notoriety on the 'other' growing forum, but it's okay for a few seedlings.

 

@Harry is right about discarding any collected seed.
The plants you grew last year are very likely to be F1 hybrids, and resulting seedlings will not be exactly the same as last years plants.

 

Hi Pete,
That is such a shame as I would so like to try to do these...

Petunia Climbing Tidal Wave Mixed -

they aren't joking about the size - they were spectacular and I saved all the seeds so I could do them this year.

 

They might be nicer ones.

 

Well its up to you of course, but I get the feeling these might actually be the kind that are vegetatively produced, that is to say a very definite strain.

Yep possible, but not really likely.
It's the kind of thing where 1 in a 100 is better, but 99 are rubbish.

 

Have a look in the seed catalogues for something similar.

 

I think I'm still going to try and see how the collected seeds turn out but will also buy some seeds as a backup.

Thanks to everyone who helped - very much appreciated.