seed trays in greenhouse drying out very quickly

I have put some seeds in a seed tray in the 'plastic greenhouse' but find the soil is drying out very quickly, does anyone have any advise as to how to keep the soil moist? Thanks!m

 

Umm I have one of those plastic covered greehouse things, not shading but have the front door open - which I open first thing in the morning and close about 8pm at night.....

 

I have just put propagator lids and newspaper over the radish, spinach (in normal seed tray), and the same over some broccoli (in newspaper pots in seed tray) and just some newspaper over lettuce (in larger tray which my propagator lids will not fit over - hopefully this will be okay... will water them tonight and see how it goes - ............

 

If they haven't germinated yet I think they would probably be better off on a windowsill.

Opening the "door" is going to increase the draughts a lot, that will increase evaporation, and they will be quite cold at night - which will slow down germination.

If you bring them in get them out as soon as they germinate, otherwise they will get leggy.

If they have germinated then perhaps move the plastic house to somewhere that does get sun all day, or gets light shade, and leave the door unzipped, but not rolled up - that should increase the humidity. Best to put a Max/Min thermometer in there though so you know if its getting too hot when you are not around to check (or too cold at night!)

 

My eyes have been opened by using sandwich bags as mini propagators. They are all off now so I haven't a pic to show you what I mean.

The fresh produce clear plastic bags from supermarkets are best because they are quite roomy. Put the seed tray in the bottom of the bag, wet the compost and sow seeds, then tie the top of the bag using one of those wire ties that you twist. Fortunately the greenhouse shelving I have is adjustable so I can then use a paper clip to hook the top of the bag up onto the shelf above. This keeps it off the seeds. As the seeds use the water it then evaporates ( precipitates, respirates (?)-never remember the water cycle I learned at school lol) hits the side of the bag then drips back down to water the seedling again. Once germination has taken place I will tear the bag slightly each day til they can manage without it.

Using paper pots I have found fungal issues galore but since switching to plastic seed cells and seed trays, I haven't had anymore problems.


I think it was Kristen who gave me the idea.

 

"never remember the water cycle I learned at school"

Water evaporates from the surface, or plants transpire it, and it condenses on the plastic. Ha!

"I think it was Kristen who gave me the idea."

Could be, I grew all my seeds in "pans" (as in "shallow pots") in plastic bags last year.

This year I've been using a windowsill propagator (no thermostat, just gentle bottom heat, and 1/4 size seed trays with clear plastic lids + vents) and I have to say that is a noticeable improvement over the plastic-bag method.

I'm still using the plastic bag method for things that take month(s) to germinate as the seed tray / propagator lid approach does dry out somewhat.

I recommend a thin sprinkling of vermiculite over the seeds (instead of sifted compost). I bought a tiny bag last year, and I doubt I have used half of it yet.