Did you try starting them in peat or newspaper pots full of potting soil so you didn't have to disturb the root to plant?

Western WA here, too, Zone 7b.

After several years of having a heated plant mat, it FINALLY occurred to me last year to use it to start beans.

I made all the mistakes: too cold, soaking, plastic bags.

Then, thinking about beans...
* They are often grown in arid lands, so they probably don't need or want excessive water. Just enough, not too much.
* They need some warmth so they don't mold/rot before or during germination.
* They are usually planted 1" deep, so maybe they sprout best underground, even though I've never read that darkness is required. Maybe it's the combination of just enough moisture and warmth.

So I plugged in my heat mat, dragged out some Goodwill cake pans (9x13x2"), half filled them with a dampened mix of soil, sand and compost, placed my seeds about an inch apart on top, then filled the rest of the pan with the same soil mix and firmed it down, then topped it off again and firmed that down. I put them on the heat mat and checked them for moisture levels every day.

I have a handy old bulb sprayer that I bought years ago, and watered with that, but dribbling water over the pan would probably work, too.

I dug around gently with a spoon after a few days, and when I saw them starting to sprout (not as far as leaves), I took them outside to sow. Most of them seemed to come up well last year, despite our cool summer temps.

I did this with Romano pole beans, rattlesnake beans, and asparagus beans two days ago, so am waiting and watching for them.

I am trying a heritage dry bean (bush) this year and have just finished preparing a 10x10ft area for them. Since they are specifically from the Southwest, I have been dragging my feet, but it's mid-June, so I know I've got to get them in... I'm trying the same heat-mat method, but putting them closer together, since I'll have to dredge around the pan with the spoon again, and they aren't sprouted enough to crowd each other. And, since I have to plant 200 (2 per sqft) and I'm not getting any younger, I am using a 3 ft length of PVC pipe to place them while standing.

Oh, another thought. If you don't have a heat mat but you have a freezer with warm sides, put the beans and soil mix in plastic zip bags and tape them to the side of the freezer. I've done this in my pre-heat-mat days, and even covered the hanging bags with a bath towel (weighted down on top of the freezer) to retain some heat, and it worked fine, but I didn't do beans.

Sue

Interesting thought about using the freezer sides. The front of my new freezer does get warm. I usually use the top of my water heater as a heated sprouting area.

Happyday, I do start several dozen beans in peat pots. That does work well and I suppose it would be possible to start more that way but it takes a lot of space for several hundred. True, sprouted beans do have to be treated with care.

Thank you Sue for the extensive write-up. The cake pan setup sounds like a winner. Misting did not work well for dozens of seeds in a pot but it should work with a pan. I have a very large grow light setup that provides warm temperatures.

Regarding light, Fusion once reported on a method of saving nearly dead old seed. He pressed them into damp seed starting mix with the top of the bean showing, gave them a dose of dilute nitrate and exposed them to bright light.

Dick

I have pre-sprouted beans by placing them in damp paper towel in small margarine containers on top of an aquarium, then planted them straight into the ground. I've also pre-sprouted them in plastic flats of potting medium (Sunshine Mix #4), the clear plastic lids let in the light and keep the medium moist, once sprouted I plant them out. When I'm only growing a few, these I plant in 3" plastic pots on a heat mat, when they have their true leaves they either get planted out, potted up like I did with Bird Egg#3 or they're planted in containers like the few varieties I'm trialling this year, small garden space at a premium. I only direct seeded a couple of varieties this year this only after the weather finally warmed up.
The way the last couple of years have been I'll probably keep on pre-sprouting most if not all the beans I grow from now on.

Annette

Even short-season pole beans need a head start in my zone. This spring I pre-sprouted about 150 seeds in damp paper towel in plastic bags with no problems at all. No rotting and nearly 100 per cent germination. I placed the bags on top of my grow lights for warmth; the lights were on for 14 hours and off for 10 hours at night. Many of the runners (scarlet and painted lady) took only a day to germinate and most of the others (blue lake and emerite) were two or three days. All had germinated and were potted up within a week.

FWIW, I grow Helda each year and thought I'd experiment with some Fortex this year. I grew half the row with Helda and the other half with Fortex. Helda is a much, much better early season and cool weather performer. Maybe they'll catch up and make me proud, but it's not looking good. Then again, maybe the taste will make it worthwhile.

I don't pre sprout because of the fidding about it entails and the fact that I cannot be sure that the weather or my free time will allow planting out when the beans are ready. I would quite likely end up with rotting beans. Instead I do early sowings in modules in the porch and later ones direct into the ground. I don't really see the point of pre sprouting when you could be planting out sturdy young plants with no more effort and several weeks head start.

Annette, your margarine containers and plastic flats are more or less air tight with no mold problems?

Macky, you seal the plastic bags? Do you do anything to prevent mold? I have wondered about very dilute peroxide.

Tcstoehr, Fortex and Emerite both do fine here. I will have to try Helda for even earlier beans.

Flora, I agree that planting out established plants works best. My problem is that I need so many. I would love to be able to set out 500-700 plants. What are your modules like?

Dick

Dick - you are growing a lot more than me so I see the problem. I only grow a 15ft row of runners for the family and a couple of rows of green beans which I direct sow later.
I use modules like the one at the link. I don't buy them specially. They come from past purchases of bedding plants.

Here is a link that might be useful: Modules

Dick, the margarine containers are airtight and I only used this method until the skin breaks on the beans, then they are either planted in pots or straight into the ground. If the beans take more than 3 days I usually rinse them and put them in a clean piece of damp not wet paper towel before snapping the lid back on. The only time I've encountered mold is when the seed isn't viable.

The black plastic flats with clear plastic lids I use are the ones sold in garden centers, they aren't airtight but with the lid on the medium stays warm and retains moisture. I just finished potting up the 10 or so Tobacco Worm I soaked in warm water for about an hour then planted in the flat, when they popped through I took the lid off and grew until the true leaves appeared. I just stick my hand under the seedlings, loosening the planting medium (Sunshine Mix #4), lots of roots but if you're gently not a problem. These are now in 4" pots until they start to run, then they'll get planted out.

If I was going to start a few hundred beans, I'd definitely use the flat method.

I'm going to take a chance, start one more variety today, I'll take pics of how I do it from start to finish.

Annette

Yes, I do seal the plastic (Ziploc-type) bags. No, I don't apply anything to prevent mold because I've never had the need. My experience has been the same as Annette's; the only time I've encountered mold is when the seed isn't viable. My method only differs from the others', it seems, in that I set my seeds on a source of warmth that is not consistent. Perhaps the fact that the heat source is off at night contributes to my lack of experience with mold using the plastic bag/paper towel method? I use the same method for other seeds such as lupines, too.

Flora it looks like I could use 5cm pots like your modules have instead of the bigger pots and get many more starts in the available space.

Or even plant them in trays like Annette does. I did not know that they would tolerate having their root disturbed like that. It sounds like one might even transplant beans in the garden. I have tried that with corn and it did not work at all.

Macky it looks like my problem what that I had a few dead seeds and I did not remove them in time so they contaminated the whole batch.

Lots of good ideas. Thank you to all of you.

Dick

Dick - I have often moved beans in the garden. When I sow in situ later in the season I usually put in a few at the end of the row to fill in any gaps in germination. Just dig them up with a trowel and transplant them. They don't mind at all.

Thank you Flora. That is new to me and it is good news.

Dick

I haven't pre-sprouted seeds before, but am having issues with bald heading and/or no germination at all of my pole beans. Is it recommended to sprout them in a wet paper towel, or should I start some in trays under grow lights? Any advice would be appreciated.

First off, how old is your seed and what conditions has it been kept in. I quite often pre-sprout older bean seed in damp paper towel enclosed in a zip lock baggie of a small plastic container. Put in a warm place they usually sprout in 4 or 5 days if viable, then I pot up in 6 packs or small pots until they have their true leaves starting to emerge, then I plant out, this has been successful for me so I stick to it. I rarely direct seed anymore, most are started in 6 packs on a heat mat in the greenhouse, out of the 3 dozen+ varieties I'm growing this year I only direct seeded one 'Blue Jay' a bush bean.
Annette

"Macky it looks like my problem what that I had a few dead seeds and I
did not remove them in time so they contaminated the whole batch."

That issue is the main reason I would recommend against pre-soaking beans or other legumes in bulk - by any method - unless conditions make direct sowing unreliable, or planting quantities too large for pots to be sensible. Any pathogen or contaminant present could easily infect the entire batch, and all could be lost.

I also have a suspicion (purely conjecture on my part) that something
is lost in soaking bare seeds, that the beans release compounds as they
begin to germinate which - if allowed to remain on or near the seed -
would offer some protection from pathogens. Any such compounds would be lost in the soaking solution.

Soaking beans in their pots after planting, however, is much more reliable. Any bad seeds are likely to infect only other seeds in the same pot. Using the methods I have previously posted on this forum, I typically get very high germination rates in peat pots, using sterile media, and boiled or filtered water. This year, of the 19 beans I started in pots, 12 were from 2006-2008, and all had from 90-100% germination.

While I start a lot of beans in pots with great success, I understand that not everyone has the space to do so... but there are options. If you plant 2 beans per cell & both germinate, you can transplant those pairs at double the spacing you would otherwise use, and get a lot more plants per flat. I use the 32-cell peat pots this way, and for pole beans, this would give you 64 plants per flat... which is a lot of beans.

You could also start large numbers of beans (or peas) in a flat of sand, from which they could be carefully pulled with minimal root damage. If using this method, be prepared to water the bare-root seedlings immediately after transplanting, and don't give the roots a chance to dry out. My preferred method is a variation of this, with peat strips nestled in a bed of sand. The moist sand prevents the tap root from being air pruned, and if this root is handled carefully & coiled into the bottom of the hole during transplant, there will be little to no transplant shock.

I've previously stated that beans were poorly suited to starting under lights, and for the shop lights used by many of us for seed starting for years (self included) that was true. Barring the use of expensive grow bulbs or re-wiring the ballasts, shop lights could not put out enough light, and bean seedlings quickly became leggy.

My experience with a new T8 setup - using 6-bulb hi-bay reflective fixtures - has changed my opinion. Due to a cold snap (actually several cold snaps) I was unable to put my seedlings outside directly after germination, as I normally would. The seedlings stayed under the lights during this period, remaining stocky & growing normally. When finally put outside, they had no shock from sunlight. I'll try to post a photo of this setup soon, I believe it would be of great use to others who grow beans in less than ideal climates.

They are new Fortex seeds from Johnny's.

I have a T5 grow light. I'm still a little lost with this whole pre-sprouting thing. I only need 10 or so plants. Can I start in starter flats, and transplant outside as soon as they germinate? Or should I go with the paper towel approach, and then take the seedling after it has sprouted a good set of roots and cotyledons and plant it? I am concerned I will damage the fragile seedlings.

I'm also having a lot of difficulty direct sowing basil this year as well. So far I am coming up with nothing, it just won't get past cotyledons. I think I need to start that under my light also.

Fortex has exceptional cool-soil germination, so if the seed is healthy - which it should be, if purchased this year - direct seeding should not be a problem this late in the season. I just planted mine directly in the garden last week, one of the only two beans I did not start as transplants (the other was Giant Red Tarka). My seed is originally from Johnny's as well, but I have been saving my own seed since 2000. (I should note that while Fortex has a mid-season DTM for snaps, it can take a LONG time to go from snaps to dry seed.)

T5 lights are even brighter than T8's & the fixtures are similarly priced, but the price per bulb for the T5's was a bit too high for my taste. Both can be excellent for seed starting. I admit, though, that while T8's are much cheaper, finding bulbs with the right spectrum & intensity can be a challenge... I had to order them by mail.

I grew awesome solanaceous and brassica transplants with my T5 grow light... very happy with it.

Soil is not cool... it was baking hot today.

Thank you Zeedman for the update on your grow light setup. Would you please supply a model number for the 6-bulb T8 hi-bay reflective fixtures and also for the tubes that you use? Thank you.

Zeedman I have been using your 6-bulb hi-bay reflective fixtures setup for several years with good success. I was wondering if you ever replace the fluorescent tubes as they age and lose some of their brightness?

@drloyd, good to see that another of the old bean gang is still here. :-)

I've had to replace some bulbs this year. They should have lasted longer, but I kept two banks on all winter in 2019 & 2020, for some of DW's plants. I don't anticipate repeating such year-long usage. These bulbs lasted 5 years, I expect that their replacements will easily last as long or longer, if only used for seed saving.

I'm switching over to led bulbs. Results over the last 3 years have been excellent with just a few lights converted. Power consumption goes down to less than 1/3 of the cost for fluorescent bulbs.

I would consider switching to LED... we changed over to LED where I work, and they were impressively bright. But when I found some high-output T8 bulbs at a decent price, I bought 2 more boxes. ;-) The combination of those bulbs & the high-bay fixtures works very well, plants grown under those lights need little hardening off. They will probably last as long as I keep gardening.