Lettuce seeding woes

[gdecaires]

I'm a gardener in Barbados and am having a hit or miss experience with seeding lettuce.

I'm using a seeding mix of equal parts peat, vermiculite and perlite. I've been wetting the mixture in the cells to get it good and moist then put a seed in each cell before sprinkling a light layer of mix on top and misting with water. I then leave the trays on a shelf in my house where them temp is 29 C year round.

Some times this works fine but often as not I get little to no germination and I'm using seeds from the same pack. I use butter crunch seeds from Johnny's.

Can anyone share some tips for a more reliable germination?

 

[Bleeckerclerk]

That is WAY too hot for lettuce. That is a cool weather crop.

 

[Chuck]

Not only is it a cool weather crop but I would guess you are covering up the seed too deep. All you need to do with lettuce seeds is to give them good soil contact with NO soil covering them and if you do cover them use a very very small amount of soil. Lettuce is one of the few vegetables that require sunlight to germinate.

 

[Oliver Buckle]

I do it in a tray, sprinkle the seeds on the surface then go over it gently with my finger tips. That way there is some on the surface, some half buried and some just under. Then I give them a water with a fine sprinkler. Something will germinate and I can prick them out as soon as, later watering I do from below.
Lettuce seed usually comes in packs of a couple of thousand, I always assumed that is partly because you are never going to get anywhere near 100 percent germination. Putting them one per cell I would expect a lot of duds.

 

[YumYum]

29C is 84F. That is a little warm but still doable. On a side note they aren't really going to like the heat after germination which will make them grow fast and then bolt on you not to mention making it bitter tasting.

You may not be storing or keeping your seeds properly. Keep them in the fridge or freezer and keep the seed packets out of the sun which will bake them and guaranteed to make them sterile.

I plant mine all Summer long in potting mix and some shade and cover them up about 1/4" deep. No problems here. I keep them damp during germination, not wet or dry.

 

[Meadowlark]

I'm a gardener in Barbados and am having a hit or miss experience with seeding lettuce.

I'm using a seeding mix of equal parts peat, vermiculite and perlite. I've been wetting the mixture in the cells to get it good and moist then put a seed in each cell before sprinkling a light layer of mix on top and misting with water. I then leave the trays on a shelf in my house where them temp is 29 C year round.

Some times this works fine but often as not I get little to no germination and I'm using seeds from the same pack. I use butter crunch seeds from Johnny's.

Can anyone share some tips for a more reliable germination?

Here's something that has worked for me to germinate and grow lettuce at temps above 29 C.

An experiment in Hugelkulture in containers

do fig trees take a few years to produce? Yes. They will sometimes produce fruit in the first year or two, but it won't fully ripen, and the tree sheds it. After about 3 to 4 years, you can expect production that fully ripens on the tree. They produce for 50 years...and I know this is true from...

www.gardening-forums.com

My climate is hot(very hot at times) and for years and years I attempted but failed at growing lettuce. One needs to germinate the seed during the hottest months to get plants started in time so it will produce before first frost.

I discovered there is something "magic" about Hugenkultur containers that enables lettuce to germinate at temps in the 80's and 90's. Now I grow large supplies of lettuce in HK containers every year. It works for me...and I suspect it would work for you also.


Check out this reference thread I posted:

Lettuce in East Texas in 100 deg F weather?

I had completely given up on growing our own garden lettuce here in East Texas after several failed attempts to do so.... that has all changed since I started using the Hügelkultur containers. I have had miserable results with lettuce in the past here. It's just too hot and humid and by the...

www.gardening-forums.com

 

[gdecaires]

That is WAY too hot for lettuce. That is a cool weather crop.

Apologies for not being more clear. I currently grow several hundred head of lettuce per month quite happily outdoors in direct sunlight using seedlings from my local nursery. It's the germination of my own seeds that's giving me trouble and the soil temp is about 24-26 degrees in my seeding room. Perhaps it's what's suggested in other posts that I'm using too much soil cover after putting on the seeds. I have seen someone else recommend simply wetting the soil, dropping the seeds on and then covering the entire tray with cling film once it doesn't touch the seeds. Might try that.

 

[Oliver Buckle]

Perhaps it's what's suggested in other posts that I'm using too much soil cover after putting on the seeds

I sow reasonably thickly on the surface , then rough up the top layer so there are seeds on top and all the way through the top 1/4 inch or so, some are bound to be the right depth. I might water with the finest rose from the top first time, but then I would water from below to not disturb them.

 

[Unfocused]

Indoor grow

I just planted: Tom Thumb, Red Leaf, Black Seeded Simpson, Grand Rapids and Red Ruby. Started in 6" pots and these will remain the grow pots as well. About 5" under the lights for about 15 hours. Temps are kept below 80° F the best I can. . I did not sow them as you did. 1/4" deep, lightly covered with soil (store bought mix) and watered every morning - sprinkled/moderate mist (anymore might move them deeper in the soil or around the corner.) This was Saturday evening Dec. 21st. and I had sprouts as of this morning Dec. 24th. Not all of my lettuce has sprouted and I'll give them a full 2-weeks before I look into what happened. As mentioned, indoor grow, in Florida with humidity in the high 90's and outside temps under 70° F. I've included a full pic of all my sprouted seeds. In an open closet with lights, heater and fan. Blacked out bedroom goes completely dark for about 9 hours.

 

[Meadowlark]

Black seeded simpson is an old favorite around here.

I've had excellent results growing lettuce in Hügelkultur containers in my climate which is similar to yours @Unfocused ...as mentioned above.

 

[Unfocused]

OP - I just when through my sprouted seedlings and noticed a couple of things.

Soil - I noticed nothing out of the ordinary with my soil moistness. If anything it could have been a touch on the dry side (I'm shaking my head no as I type this but I must type it) but I'm not so sure. Maybe my initial watering wasn't enough? Cannot check this now but I'll pay attention next time.

One of my plantings (Red Salad Bowl) I had minimal sprouts. I am blaming this round on my planting. I started 5 clumps - 2-3 seeds per clump, I wear glasses so eh - and only 3 seeds germinated. I've transplanted along with the others.
One of my plantings (Ruby Leaf) I got nothing - I'm sure I put seeds in there, glasses eh... I am honestly confused here as to what happened. I'll do better next time to make sure I've actually planted something.
The other x3 plantings (Grand Rapids, Black Seeded Simpson, Tom Thumb) all are going well. I didn't think I planted that many seeds but I'm good with it.
I've also had to transplant, move, build, make noise, and just have an overall dismal start to my growing. However, the plants are growing and I am working to make it better. I'll keep you posted of my progress over the next few weeks as these mature into dinner. I will start another batch of the failed seeds of the Ruby Leaf and the poor planting of Red Salad Bowl. I'll pay more attention to my process and relay this hoping it might help.

I am growing under lights but have had to move these lights around as my seedlings sprouted. My next round I will prevent this so I have better control over my process.
I am using a store bought soil.
Sourced seeds from a known and reputable grower from Orlando, Florida.
Tap water that aerates ( read: breathes) on my counter for a minimum of 48 hours. Been doing this for decades.
Lights on about 14 hours a day - no timer yet. Room blacks out completely when lights are off.
Temps monitored and kept in the 70's. Hard to do with our temps swings but it's not getting below 69°.
Seasonal Florida air temps are upper 40°'s with low 70°'s or upper 60°'s. High humidity almost daily - 97% right now.

Pic is of my lettuce table - a couple of slow learner pepper plants.

 

[Chuck]

One thing that caught my attention is the size of your containers. Those are large containers for seedlings and the larger they are the more difficult it becomes to maintain the proper moisture level. The soil will become too dry on the surface and the lettuce seedlings roots are still very shallow.

 

[Unfocused]

Good point and thank you. However, when transplanting into those pots last night, the smaller pots they were in soil that was moist - however, maybe towards the dry side - learning experience. I also wasn't sure when to transplant the seedlings so from what I am reading from you I may have jumped the gun ? My only prior lettuce grow was outside in Missouri and it was a total success with lettuce coming up all season long... picked a salad every night for months.

These seedling sprouts had long runner roots already - over 2" on most of the good sprouts. Others had balled up and I didn't disturb this.

Edit: I should add that the lettuce sprouts were transplanted into 6" pots. The bigger pot is a pepper plant. I did notice that after transplanting - most were clumped together - that all of the sprouts perked up and this morning I saw nothing but happy plants ( Bob Ross )

 

[Chuck]

Good point and thank you. However, when transplanting into those pots last night, the smaller pots they were in the soil was moist - however, maybe towards the dry side - learning experience. I also wasn't sure when to transplant the seedlings so from what I am reading from you I may have jumped the gun ? My only prior lettuce grow was outside in Missouri and it was a total success with lettuce coming up all season long... picked a salad every night for months.

These seedling sprouts had long runner roots already - over 2" on most of the good sprouts. Others had balled up and I didn't disturb this.

When I first transplant lettuce seedlings they have at least the first set of true leaves and are about 2" tall. I start lettuce seedlings in 1 1/2" x 1 1/2' x 2" 6 cell containers and 2 or 3 seeds per cell. If I am growing Bibb lettuce I thin to 1 plant per cell. I then plant these seedlings into a 2 gallon fabric container using the hugelculture method. The lights I use are 4ft T8 flourescent and I keep the lights about 3 inches above the plants 14 hours per day.