Growing grass in seed tray

Hi, I picked up a 3 pack of seed trays and was thinking of experimenting/learning by growing some grass in one of the trays but I have a few questions.
1. I currently have a bag of topsoil and a bag of lawn & turf dressing to hand, can I use either of those for the soil, if so, which should I use? Or do I need to go get compost?
2. Assuming I fill the tray up with one of the above, how high should the tray be filled with the soil?
3. Would I then just layer the grass seed on top and maybe put a light dusting of soil on top? How much seed should I put in?
4. The tray has holes in it, so if I water the tray it is possible the water will seep through, so in terms of where to store the tray, can it be outside? Or would it make sense to have indoors at back door where the sun shines in the back door window?

Any other tips, advice, suggestions more than welcome.

 

Thank you, very helpful.

I will initially just do it on one tray, my plans are really more to see how the whole process works on a smaller scale before over seeding the garden at some stage, although probably easier to germinate on a smaller scale especially considering garden soil is not great.

 

I agree with JWK but I had some left over seed compost which I used. Did a great patching job. Watch out for pigeons when scattering your grass seed in the garden.

 

It's not difficult to grow a seed tray of grass, as @JWK has described, but that isn't quite the same as reseeding part of a lawn.
The conditions in a large area of grass are different from an actively cultivated tray of grass seed, so it's only useful if you're digging out a similar sized area of lawn and replacing with the tray contents. That can also be tricky because the grass can be a different variety, so the effect isn't always uniform or attractive, for a while anyway until it all blends in a bit more. It's why it helps to broadcast more of the same seed over the entire lawn.

 

Thanks fairygirl. Yep, 100% I’m aware it will be easier to see better results in a seed tray vs over a larger area like an active lawn.
I had overseeded my lawn last year following advice on here and I don’t think there was any real improvement.
I started another thread yday seeking advice where I want to focus on a smaller patch in my lawn and see can I improve that area first to hopefully give me confidence that whatever I do in that patch will work across the rest of the lawn after. I find when you don’t see improvement it can dent your confidence!

Improve section of lawn

 

Looking at your link to the other area, it looks very dank, and poorly draining. Grass will often grow quite happily in shadier sites, depending on the type, but it needs decent drainage, hence the moss. If you apply a moss killer, you'll need to wait a while before seeding though.
I'd say really spiking the area - pushing a fork right in to a good depth, and thoroughly scraping and scarifying it all will make a better base for seed. You may need to do that a few times, and then add the seed mixed with a bit of coarse sand and decent, finer compost. Firm it well to get good contact and then see how it does over the next month. It should germinate quite quickly.
Water if necessary - and that always depends on your climate, but you probably won't need to do much in that regard due to your location!
Feeding isn't necessary unless you want to leave it for a good while too, to let that have an effect, and it would be something like a general feed - BF&Bone for example. Better to just improve the area, sow, and feed later on in the year [if necessary] once it's established, although it may be a bit late by then. I don't know if the autumn feeds will suit a newly sown area - I've never used them on lawns I've created [the one I did here 10 years ago was sown in mid June] as I've usually prepped early enough [with the BF&B] and the grass has still been fine by late summer/autumn.
Any area which gets regular traffic on it will always be poorer generally, due to that compaction and wear and tear. In the same way grass can get with children using it through summer.

If the underlying soil is solid and compacted, it will always be difficult to have it looking really good, but it also depends on how fussy you are about that. Most gardeners don't need, or want, a bowling green, just some half decent, green grass that doesn't turn brown in hotter, drier summers.

 

Just to report back here, I planted the seeds in the tray around 2.5 weeks ago. I added the topsoil I bought to the tray, added the seeds and kept it in a half sheltered area in the garden and watered daily unless lots of rain.
A couple of pics of how it turned out which I am happy with, so thanks for the advice on here .

At the same time, I also added some topsoil (around 2/3cm) to a couple of bare patches in the garden and added some grass seed. I wanted to see how the grass in the lawn grew Vs in the tray. I had aerated the areas around the patches in the days preceding adding topsoil and seed.
You will see the result of the seeding of those patches in the pics too - TERRIBLE. I regularly watered etc. and the only thing the patches seemed to attract was a few white slugs, not a blade of grass.

Any suggestions on an alternative approach to try and get seeds to germinate in these patches?

Thanks

 

I sowed it exactly how I sowed it in the seed tray, which had no issues. That also included spreading a dusting of top soil on top of the seed.
Granted the seed tray had the same top soil throughout the tray whereas the lawn has the existing lawn soil with an extra 2/3cm of additional topsoil on top of the patch and it is easier to grow in a seed tray.
Just the fact that the two patches in the lawn I tried to seed, nothing happened apart from a load of white slugs crawling all over it.

All the previous seed is still sitting there, so so I try disturb the soil, add more topsoil, seed and go again?

 

Did you firm the seed in well after adding a little sprinkle of soil? It's often easier to mix the seed with the soil and then broadcast that, rake it to get it level if needed, and firm down, although if it was just those wee patches, you wouldn't really have needed a rake - just your hand or a hand fork.
As @JWK says, heavy watering can dislodge the seed, so you need to be fairly gentle, or allow the weather to do the job. It can take 2 or 3 weeks to germinate anyway, depending on climate and temps. I think it's worth giving it a scrape over and just repeating the process though.

The amount of slugs suggests it's all quite wet though, so maybe don't go mad with the watering!

 

So you have proved that the seed that you have is viable. Next suggestion is to pre-sprout the seed before sowing. Put a quantity of compost/soil mix in a bucket and add a proportionate amount of seed (by calculating the volume of the area you wish to fill) Mix thoroughly, adding sufficient water to make the soil mix damp but not wet. Set aside for 3-5 days.
Having previously removed bare soil from the area you wish to plant, apply the now sprouting mix evenly and firm down with the back of a spade or heavy board. Cover with mesh to keep birds and /or cats from the area.
If it hasnt rained in 5 days, lightly water area every few days.
For very small areas, use the grass plants you have in your tray already, to fill slots you make in the turf with a bladed tool. Firm and water.
Resist the urge to mow until the grass is well established (several weeks), then lightly trim, reducing height each time.

 

Thank you both, very helpful replies and I will try these approaches for the two main patches I had no joy with.
Weather is very wet at the moment here in Ireland, so I will wait a couple of days and go again.
I will report back in due course.

 

I hope it does well enough for you. It's always quite difficult to judge something when you're not there in person to see it all
You'll probably find you won't need much watering for those little areas. When I created that new lawn here I don't think I had to water at all because there was enough coming out the sky, but many areas find that spring and autumn are better because it avoids the hand watering needed due to higher temps and less rain. The spring and autumn temps are often too low here for sowing, and soil doeesn't warm up as quickly, so summer is easier. If you have clay soil, it takes longer to warm up.
The prep is always important - just as it is with planting something in a new border. Any plant can only thrive if the conditions are right for it, and people often skimp on the soil prep, but it's usually the most important part in order to get success, whether it's grass seed or a large shrub.