Soil blocks vs coir pellets vs ??

[Vanisle_BC]

(Edited)
I wonder if coir or peat pellets would suit me better than the 2" soil blocks I've been making. Has anyone had experience comparing these/other methods of seed-starting?

[pepperhead212]

I have better success with pellets, and not just because I'm lazy, sometimes! Many years ago, I tried pressing cubes, but never really had great success, though others had great success. (I don't even remember where that press I have for that is, though I have an idea). I've used the Jiffy Pellets and the Ferry Morse coir pellets (a little smaller) for various things through the years - usually things that won't stay inside long, just one or two sets of true leaves, and as soon as I see roots showing, they get planted. Things like squash, okra, cucumbers, and similar things. A couple seasons ago, however, I didn't have enough space in my last tray for my eggplants, using the usual pots, but it had plenty of space for even more Jiffy Pellets, so I planted them in those. Well, those EPs, once they started growing, took off! In less than a month, I had to put the pellets into a larger pot - the 3x6 in a tray size, and in just a couple weeks, they were huge, and some rootbound in those pots. Here's a photo of the plants that I started seeds in Jiffy Pellets on 3-27, and transplanted on 4-23.
Eggplants and one Carolina Reaper, replanted in larger pots, 4-23 by pepperhead212, on Flickr

And here are those plants just a week later!
13 eggplants, hardening off, 4-30 by pepperhead212, on Flickr

[Vanisle_BC]

Thanks Pepperhead. Do the Jiffy pellets expand much horizontally? Space is an issue for me.

[pepperhead212]

Not a lot. The Jiffy Pellets are about 1 5/8 to start, and the FM about 1 3/8, and both go out maybe 1/16", when they expand. I think the netting just keeps it going up, instead of out.

And here's a larger tray, showing a 6x6 batch of Jiffy pellets, plus a few more - not sure how many fit in a regular tray.
Jiffy Pellets, with the soaked seeds for okras, melon, bottle gourd, calabash, and cucumbers. by pepperhead212, on Flickr

[applestar]

I’m “re-visiting” coir pellets— have tried jiffy pellets in the past.

I think the pellets have similar root air-pruning advantage to soil blocks. The netting keeps them more intact and somewhat easier to handle. Soil blocks by their very nature are heavier and more dense, but without outer support, holes can’t be dug and more advanced rootballs can’t be planted in them

The root blocks are PACKED so requires quite a bit of potting mix — at least 1.5x minimum, as much as 2.5x I suspect.

I tried origami paper pots, too, to try saving on the amount of mix.

If you’re used to the 2” soil blocks, the smaller volume will seem inadequate and seedlings may need to be uppotted to another interim size before weather is ready for planting.

Tomatoes in particular and many other seedlings benefit from being planted deeper as seedlings, especially when needing to recover from growing a bit too lanky or spindly due to inadequate light. = Interim uppot into taller container OR plant out outside with or without protection….

If you are experienced with soilblocks then you might not run into MY problems from packing them too close in the tray and having them grow roots into each other.

Saving space earlier on can be done in varieties of ways including recycled containers. I’m acknowledging that UNIFORM sizes makes for better organization… And have invested in some cell/plug trays to try. Cutting them up into smaller number of cells has solved some of my issues with full size plug trays and uneven seedling growths of same kinds and varying requirements of different kinds.

But my biggest issue in the past was needing to go deeper. Jiffy pellets do come in “tomato” size that grow extra tall.

But I’ve also been noting that seedlings grow “bigger” when they can stretch their leaves out AS WIDE as as the roots CAN. And limiting the rootball diameter to save space do seem to stunt the seedlings as compared to seedlings that are allowed to grow more freely.

[Vanisle_BC]

After some (online) 'research' I think I'll stick with what I've been doing. Among other reasons; Jiffy Pellets use 'endangered' sphagnum moss and most others involve some amount of plastic which I try to avoid.

I do have lots of plastic pots which I re-use until they fall apart. Would like to find a good eco-friendly alternative - paper etc. - but none I've tried work very well. Meantime the plastic I've collected over the years will outlast me anyway.

I usually germinate/start in 2" cubes under lights, then cull & and up-pot; the cubes can be buried well into the soil of the pots if desired. The young plants stay under lights until hardening-off time. It's interesting how experiences vary: Although my blocks have only about 1/8" separation from each other, I don't get the root tangling that Applestar mentions. In fact the roots seldom emerge much from the blocks.

Last year was disastrously hot & dry. This year looks like being worse. I'm puzzling over where to locate or how to protect my plants when summer gets going. My wife grew a hanging tomato plant last year, in a place where it got no sun at all. The yield was not great but she did get tomatoes. Hmm...

[imafan26]

Interesting discussion. I have not tried soil blocks. I have tried pellets. They stayed to wet and I had problems with it. I start most of my seeds in compots. It saves the most space. I usually use 4 inch pots and put multiple seeds in a pot. That way I have fewer empties. There is a larger soil volume so the plants get bigger roots. For most things like tomatoes, eggplant, cucumber, beets, lettuce, peppers, green onions that are not hard to transplant, this works out best. I may still have problems when putting them into individual pots, because then I have a real space issue. I try to directly sow things that don't transplant well.