Help With Growing Seeds

Yes but why oh why are they always differing sizes ?

 

I have been buying silicon ones, they're expensive but should be reusable for many years. And they're easy to pop the plants out of, being flexible.

 

I get all my pots and trays from the local community garden where folks bring in all the ones they don't want. Mind you I have some trays that must be 30+ years old but I tend to use pots and plug trays these days as I sow small quantities.

 

Okay, I’ve had reasonable success with seeds so far, had the odd tray where just one seed germinates, but that is still success! I have managed to prick out some seedling, but what do I do when they go floppy, which I mean not standing proud by themselves?

 

Likely due to the disturbance of their newly formed roots. When pricking out its best to have presoaked the new compost, form a hole and insert the seedling with as much of its rootball as possible. This is the reason to sow thinly.
Close down the hole gently but firmly. A stick or pencil is useful for this.
Resoak, drain and place in moderate shade until your 'soldiers' are all standing to attention (2 days ?)
Grow on in improved light, regulating temperature and light to suit. Water as needed.
Acclimatise outdoors prior to planting out, probably mid May.

 

Okay the weather is warm and looks good for the week ahead to start hardening off?

 

Beware potential frost(s) next Sat/Sun !! Other forecasts are available....

 

Cover them to keep the humidity in. Flopping/wilting happens when they're transpiring more moisture than the roots are taking up, so reducing transpiration until the roots get settled in the new pots helps.

Some of my tomato seedlings flopped after I pricked them out yesterday. My fault probably, I took them outside to do it (it was warm and sunny - probably too much for them at that stage). I stood the pots in a tray, took them back to the back bedroom windowsill and put a propagator lid over them. They'd perked up nicely by this morning. I'll probably take the cover off tomorrow, then think about hardening them off in a few weeks if the weather is suitable.

If you don't have a propagator top, or it's not tall enough, you can use the top halves of plastic soft drink bottles (one over each pot) or transparent plastic bags with sticks to stop them touching the leaves.

 

It has been very warm here in sunny Bexleyheath, but infradig says it is going to get a bit colder on the weekend, not frost but going to full down to 7 degrees, would this be too cold to leave plants out overnight?

 

Depends what the plants are, how big they are and how long they've been outside.
I've moved a lot of plants out of the greenhouse this week, they are all a good size, live permanently in pots and are half hardy and they will not be moved back in until October.
6 - 7°C might slow them down for a day or so, but that's all.

 

On a side note I sowed some petunia seeds today, using the suggestion on here and that is to mix it with fine sand. I have never had luck with petunias, so here fingers crossed.

 

The forecast * I use,which is often pretty accurate for the Solent area, said 1-2 degrees C for Sat/Sun, and has since given similar for Mon/Tues to Thurs/friday.Expect it will depend on cloud cover but being coastal, it may change rapidly. Fingers crossed, tarps to the ready!
*
https://www.theweatheroutlook.com/

 

What’s is the latest I can start to sow seeds?

 

Depends what seeds you're talking about.
I sowed Tithonia and a variety of Ipomoeas the other week and they've germinated as has basil, a variety of winter greens sown at the same time. I've not decided about fennel but I can either sow that in May or after midsummer; I still have Aztec Broccoli to sow and you can sow lettuce in a cool spot all summer, carrots, peas, French and runner beans, swede can still be sown

 

I sow certain seeds pretty much all year round.
In winter its the ones that need frost to break dormancy, in summer it biennials and in spring its mostly summer growing things.

So it depends on what the seeds are.

If we get a frost around here next week it will be catastrophic.