Greenhouse Seed starting

Hi, would appreciate any advice for starting seeds in the greenhouse. Thank you.

Hi Ron. Haven't seen you before... Welcome from Atlanta, GA!

I don't have a greenhouse yet, but it's on hubby's to-do list!

I know you need light, protection from wind/cold, and lots of containers filled with Mel's Mix. I'd certainly check them daily... Warm water would be a very good thing...

I'm sure some of the others will be along in a bit to add to this. :-)

For me, the same factors apply for a GH as in starting seeds indoors: appropriate soil temp and light.  Your climate will dictate parameters for both factors.

My latitude is far enough north that winter days are pretty short.  Then throw in our frequent heavy cloud cover, and there's just not enough light or passive solar heating potential to make it worthwhile to grow in the GH in winter.  In your climate, you might have enough light and heat this time of year that you won't need to supplement.

I started seeds in my GH last week.  I have a soil heater in the MM, and florescent lights just a couple inches above the MM.  

I don't sterilize anything, but I do keep a circulation fan going year round to minimize dampness and potential mold issues.

Some of the faster growing plants, like greens, I plant at the recommended spacing and leave them in the box to maturity for an early harvest.   For something like broccoli, I plant 5 to a square (dice pattern), and when they're ready, I transplant 4 of them to outside boxes, and leave the center plant to grow to maturity.

Hi, boffer! So do you actually start the seeds in a SF bed in the greenhouse, at the recommended spacing?

Hi, Ron. Welcome to the Forum from California! I start most of my spring seedlings inside in 2" pots under shop fluorescent lights. Some things I do directly sow in the warm spring or late fall. Take a look at Boffer's garden and green house on his website (the little world icon).. He is able to cover most of his boxes with plastic for early or late extension of growing. http://boffer.us/veg515/

Scorpio Rising wrote:Hi, boffer!  So do you actually start the seeds in a SF bed in the greenhouse, at the recommended spacing?  

Hi! Yes, I start seeds in SFG boxes at the recommended spacing in the GH, just like I would direct seed in outside boxes.

I direct seed most of my cool crops, and for warm crops, I start seeds indoors and then transplant. That seems to work best for me in my climate.

I live near Sanderson and am zone 8b.  My greenhouse is a tent variety and I grow in it year around.  We get a very good amount of sun during the winter where I live so my plants/seedlings thrive outdoors.  If we have a deep cold snap (which for us means low 20s) I cover the plants with a second layer of protection and do have a small heater that is set to a low temperature threshold to keep the edge off in there.

I sow my seeds in 8" x 24" window box plastic planter boxes and sow them with a 4 inch spacing or 8 inch depending on what I'm planting.  That way when they're large enough to transplant (or the weather is warm enough) there is very little disturbance to the roots.  

For lettuce starts, I simply scatter the seed and have found that I can tease the plants apart when they're small with very little loss of seedlings, so I plant fairly thickly.

Hope that helps!

Thank you all so much for your input. Lots of good ideas and I'm sure I'll use at least some of them.

Very helpful, thanks all!

Ron Mason wrote:Hi, would appreciate any advice for starting seeds in the greenhouse. Thank you.

 
As a general rule most veg seeds like 12  to 20 degrees o C , they like the   20 o C more than the 12 o C  ,so if you can get & maintain that in the growth medium and have a light  fleece on top to keep heat losses down you'll succeed in germinating  most of your veg seeds .
 How you get the heat depends whether you can heat the growing bed from underneath or inside of the soil ,  as well as have some heat in the air to stop the frosts killing off the new plant tips but not too much to dry ouit the soil or  burn the tender new shoots .

Flowers appear to be so pretty & smart that they will only perform if the temp is 18 to 22 o C most of th time .

 In Mel's book detailed in my strap line , Mel gives some charts that show the germination temperatures for most common veg .. perhaps you 'd do better looking in there  for the general  advised temps .

Do be aware thought that some packets of seeds will show a differing temp due to their differing varieties .
It's a good idea to make easy to read notes about those / that  packet( s)  of seeds.