Is there a trick to starting larger tomatoes from seed?

[HudsonValley]

Hi, all,
This was my first year starting tomatoes from seed, and my second year as a tomato-grower. I had good success using Jiffy organic seed-starting mix, standard-issue heat mats, and T5 lamps on a timer for 16 hours/day for cherry, paste, and small- to medium-sized tomatoes (Black Krim, Chocolate Cherry, San Marzano, Marglobe, etc.).

I had far less success with the larger-fruiting varieties. I managed to grow two German Striped plants and four Cherokee Purples, but that's about it. One Brandywine seed germinated of four, but the seed cap stayed on and after a week, I took away its real estate. Mortgage Lifter had similarly poor germination, but one grew for a while, and then died. For future reference, I'm wondering whether there is some trick I'm unaware of... I'd appreciate any advice that will help me join the big league someday!

[KC.Sun]

If the seed cap is on, you can spray with a water bottle and the moisture will eventually help remove the helmet on your tomato seedling.

Are you using new or old seed? What are storage conditions for your seeds?

If you are using old seed, you could use Carolyn's seed wake up method with miracle grow or another dilute fertilizer.

If you are using new seeds, your seed storage conditions may be drying them out. (One possible idea.)

Outside of that, I don't always get 100% germination right away. Sometimes seeds are slow to germinate. It can be a combination of both slow and fast seed germination for the same seeds from the same batch.

Are you using a humidity chamber? How deep are you planting? What is your seed source?

[HudsonValley]

Thanks! I'll keep the seed cap removal tip in mind next year. As for the seed sources, the Marglobe and Cherokee Purple seeds were saved from last year's plants, and they germinated well (3/3 and 4/5). Of the 18-20 other varieties I planted, all but the Brandywine seeds were newly purchased from Remy's Sample Seed Shop, Johnny's, and SeedsNow. The Brandywine seeds were given to me by a friend who received them with a copy of a magazine (Country Living?), so perhaps they weren't high-quality. I had good results with purchased seeds for Dwarf Adelaide Festival, Amish Paste, Black Plum, Roma, San Marzano, Black Krim, Napoli paste, Red Pear, Sub-Arctic Plenty, Siberian, and one other whose name escapes me. All of my seeds are kept in their original packaging placed into Ziploc bags and a Sterilite shoebox. Is there a better method?

I planted all of the seeds about 1/8" deep and kept them under domes or slightly vented Saran wrap until germination.

Maybe I'm meant to be a member of the tiny tomato club?

[Gerardo]

Sounds like you've got the routine down. If you were able to get Black krim all the way to fruit, then bigger ones shouldn't be an issue. CP can be temperamental from year to year, same deal with the bwines. Perhaps get seed from an alternate source and start with other larger ones, like Pervaya Lyubov, Wes, Larisa, Daniel Burson, JDs SCT, Daniels, Nicky Crain, Dester, A Ginny's Purple, even Copper River can put out some big ones. Tons of big ones to choose from.

[luigiwu]

They all start the same for me. Especially if you use a heat mat - though becareful, depending on how you've set it up, if you don't have a heat adjuster for it, it might be hotter than you think it is. I set my seedtray elevated a bit so its not directly on top of the heat mat.
Are you also familiar with Craigs Dense Sowing series? Its pinned up in the Starting from Seed section and is a series of MIND BLOWING videos... It a game changer.

[zipcode]

Well, use biggest seed, and you will get biggest cotyledons so in the end a slight advantage in early growth.
Everything you are doing sounds good. I just put them on the room heater (in spring it's still working), I get germination in 3-5 days, usually 100% from my seeds. Make sure the soil is always wet on the surface and the seed deep enough to avoid caps.
If seeds are not yours, yeah, that's a problem, I have poor results also, depends where you buy them from, I'm convinced many of the seeds I buy are way older than 5 years, considering I get much better germination from my own which are 3-4 years old. I had one this year germinating after I transplanted the seed I replaced it with (so like 1 month after seeding it, no joke)

[twillis2252]

I used Craig's method for the 1st time this year. Sowed 30 varieties and had over 200 plants. I planted 70 in my garden and gave away the remainder to my friends and church family. Highly recommend Craigs method!

[kurt]

I have been using Amiduetch's(member here) recommendations as to inoculate young seedlings(I include soaking seeds prior) with AZOS and dusting rootballs at transplant with Mycos(fungi).Good results on early root formations.

[oakley]

I agree your method is good. Just get the larger seeds down a bit deeper and make sure your start soil is damp and tap down before seeding. Just a thumb tap in each cell. To water set in a tray to bottom feed. If watering from above the seed, especially the larger ones, will want to 'float' to the surface a bit.
Same thing happens direct seeding in the garden especially peas. I tap the soil after planting with the back of a garden rake. Setting the seed firm.

I've used craig's seeding method for years even before i saw his videos. I've always called it 'speed planting'. I get great germination and have potted up about 300 this season. Gave about a hundred away, have room for about 150. Still a bed to go in and have 'insurance' plants just in case. Something happens it seems every year....this year it is chipmunks i'm trapping tomorrow...

Save seed from your prime tomatoes so you will have many for next year. Best to start many more than you need as they are free. If you want to purchase use a good source.

[zeroma]

One method I've used when my garden space was very limited and I needed to be sure of the exact number of viable seedlings I'd get: sprout the seeds wanted on damp not soggy paper towel inside a zip lock baggie not sealed tight. I place on a cookie sheet in the kitchen and keep an eye on them. Once they just start to sprout, I plant them in their small pots. I like the ones that are at least 3" x 3" and as deep as I can find. I have even used solo drinking cups with holes drilled into the sides and a few in the bottoms.

The deeper the better for healthy long roots.

Once the sprouted seeds are planted, I put the pots or Solo cups on a tray with the grates on the bottom and put that into a tray with no holes. Water bottom only. If I put too much water in the trays, I can just lift the tray with the grated bottom out, dump it out. This method of bottom watering prevents damping off and over watering. The soil wicks up what is needed and no more.

Also, when the seedlings have their first 2 sets of true leaves, start a 1/4 or 1/2 dilution of fertilizer once a week and after 2 weeks, use 1/2 to full strength dilution.

I don't use a starter soil with added fertilizer. That is just overkill as the seed provides all that is needed until the 2 sets of true leaves come in.

When in doubt as to how old the seed is, I double or triple the number of seeds I know I want. If you know your seed is older than 7 or 8 years, use Carolyn's seed wake up method. It worked for me with seeds 12 years old or so.

Large fruited tomatoes to my knowledge should germinate and grow the way all the others do. They just take longer to grow as most are late season types. Good luck.

When I've lost a few of my plants early in the season, due to them breaking off or a cutworm getting to them etc. I take cuttings from the plant (not a diseased one, you just keep the disease going) stick it into the ground and keep a close eye on it to keep it moist.

Good luck.

zeroma

[HudsonValley]

Thanks, everybody, for the seeding/planting advice and suggestions of new varieties to try, videos to watch, etc.! You folks are so knowledgeable. I did not know to select the larger seeds, for example, but it makes sense. (Why don't the seed packets tell you that?) I will be well prepared for next year; I'm planning to give them another try!