[jambop]

Does anybody on here make compost blocks for propagating their seedlings or modular sowing? I have seen a few videos on youtube suggesting that this is a better way of bringing on plants because it "air prunes" the roots rather than the roots training themselves into a circular fashion around the inside of a pot. The advantage is then that the plants spread their roots much better into the surrounding soil when transplanted giving a more extensive root system and thus stronger growing plants whereas pot grown plants continue with their circular root habit.

[Aunt Sally]

I’ve never tried it.  I use deep root trainers which do the same thing without the bother of making them.  They last for many years too.

[jezza]

Hello I've used Propapak polystyrene block makers they're about worn out now had them 20 years there was 1,2,3 inch sizes in a pack of 6 I don't know if they're still available , I have  compost block maker it's a bit seized up  I'll take a pic you might be able to find one some where or pop down to a market garden that grows lettuce  if they sow their own they might run you some blocks off  wherein used to work Friday was sowing day we would run 10.000 blocks an hour out  plus any orders and spare blocks for an allotment  jezza

[rowlandwells]

I used to sow  quite of few seed i compost blocks  but block compost seemed to be  discontinued so left of block making but i must admit root trainers seem the way forward  and we will need to invest in buying some for next season

[Mr Rotavator]

I use compost blocks as I find them a bit of a time and space saver and I did not want to buy more plastic. I'm not convinced about the 'air pruning' unless you keep on top of the watering and the blocks separate from each other and sat on a mesh.

The biggest issue I find with soil blocks is them drying out and then getting them wet again. To overcome this I put my blocks into trays and close together with cardboard in the bottom to keep them moist. The top of the block drys out and the bottom, which is in contact with the card stays moist. As a consequence roots will grow into the card from quick growing, large seeds such as courgettes and squashes so I transplanted these into pots along with chilies due their length of time they need before planting out. The large squash and courgette seedlings also break the blocks in half on a few occasions but this is not an issue if handled carefully by their leaves.

Also I have been planing out some seedlings much earlier this year as when I see roots on the edges of the blocks I've felt the urge to do so. My multi sown leeks and beetroots were planted out very small and doing fine along with singular sowings: beans, cauliflowers, calabrese, sweetcorn, banana shallots, tomatoes and cucumbers. Kale and swede is due to be planted out this weekend.

I use the mini 4 soil blocker. My micro 20 is gathering dust!

[Potty Plotty Lotty]

I gave mine away many years ago. Although it worked OK and I appreciated the efficient use of space once I tried paper pots I was converted!

I found I could make the blocks fairly easily if I used sodden multipurpose peat based compost. Anything less wet tended to fall apart. The excess moisture (and therefore some nutrients) got squeezed out in the block making process.

[Mr Rotavator]

I'm trying to go peat free and this is another issue with blocks. Also didn't think of the nutrient issue but if you get the mix right not too much comes out.

I think I will give paper pots a go but the time making and not having paper is a problem. I did sow my runner beans into toilet roll tubes.

[jambop]

Thanks for the replies. I think the watering issue is a consideration because I think that these things are used extensively by smallholders and farming. They will be using an automated watering system so it won't be an issue for them but the ordinary gardener will water less frequently and things dry out. It is a more eco friendly way to go but needs a bit of planning. I suppose another thought is how many plants are you bringing on commercial producers are making up tens of thousands the gardener not that many. The root trainer pots are interesting and not too expensive 32 for €15 ... I have hundreds of plastic pots though do I need more

[Aunt Sally]

Yer pays yer money and takes yer choice, me dear.