Seed starting experiment - soil mixes

[Mr_Yan]

So this weekend I will be starting an experiment with different soil mixes for starting seeds. This idea hatched from my reading the Peat Pots thread in the tools and equipment forum here. In that thread @Logan mentioned that peat was being phased out in the UK.

I mainly use a soil block maker to form soil cubes to plant in so that is the primary focus but will run a psudo-control with plastic 4 packs I have sitting around.

My normal soil mix for making blocks is 2 parts peat, 2 parts compost or native soil, 1 part sand, and some granular fertilizer. And, I find it works best if I run the medium though a 1/2" screen to remove rocks and twigs.

My native soil is very sandy. Call it a loamy sand in most areas of the yard and garden.

For the experiment I plan on using a peat mix, a coconut coir mix, a perlite mix, a mix sawdust.All of these are used to "lighten up" a soil mix - what else can I use. Any other mix ideas?

I'll probably plant basil, green beans, and beets in this.

 

[Mike Allen]

Coir & perlite is sufficient.

 

[Logan]

What about a peat less mix ?

 

[Tetters]

What about a peat less mix ?

Quite a few peatless ones have been mentioned - do you have an alternative idea Logan?

 

[Meadowlark]

I would add native soil as a baseline. Experiments are very good. Its how we separate the truth from the hear-say.

 

[Logan]

Quite a few peatless ones have been mentioned - do you have an alternative idea Logan?

No I'm afraid

 

[DirtMechanic]

This may be of some use.

 

[Tetters]

Are you having a laugh @DirtMechanic my brain is only about the size of a pea - triangles and numbers mean nothing to me..

 

[DirtMechanic]

Oh no. There can be quite a few choices it appears, and germination with coir or peat or what have you still does not include a moist paper towel in a baggie on top of the fridge.

 

[Mr_Yan]

Sorry guys. I got swamped at work and didn't even start this yet.

I'm adding a coffee ground mix to the lot for 2 reasons.
(1) I've been living on coffee
(2) coffee isn't that far off charcoal is some superficial ways
(3) coffee is supposed to be high in nitrogen
(4) coffee is supposed to maybe have some anti-fungal / anti-microbial properties
(5) I've been living on coffee

 

[Tetters]

I remember using well composted bark in the mix for cuttings (we grew shrubs, conifers and climbers at work) and it opened the mix out very well for that job. All our mixes then were peat based though, and now evidently the peat is to be removed from the shelves soon - or so we were informed on our TV programme Gardener's World last evening.

 

[Mike Allen]

Hmm. What exactly are you looking for? Cast your mind back to infant school days. The teacher gave you a piece of blotting paper. Wowe, thgat was costly in those days. Along with the bit of blotting paper a few seeds.. Mustard and cress. Hey the cries of exaltation. Within a few days the wetted blotting paper now had seeds growing on it.

Now back to basics. In most cases, seeds require very little to germinate. Basically, warmth and moisture. I recall as a kid. The owner of the local hardware shop, shortchanged me. Somehow I came away from his shop with a packet of carrot seeds. Arriving home, what do I do with these? So I lobbed them down the area, the basement. Time passed and one day. Dad noticed a clump of carrots growing out there. Years later in practical gardening and horticultural sciences, I learned that, soil/compot arround seedlings amounted to nothing but a supportive structure. Then further on. as the plkant grows, then it requires help. So we add compost, we feed and water it and so that tiny seed is now on it's way.

 

[Tetters]

Funnily enough Mike we were only talking about the jam jar/blotting paper job at school recently, and we grew some Bridgewater beans in the same way. Once sprouted they needed potting up though, and that's when we had to put them into something else to get them on their way. They are now in the garden with the worms and bugs

For cuttings and seed sowing, the mixture needs to be fine and it needs to allow air in. No feed necessary at that stage. For Zigs cactus we have been discussing finely composted bark with horticultural grit.
I think that for plants staying permanently in pots, it will be a case of letting the individual plants tell us what they need.

 

[Mr_Yan]

Yes I used to like the paper towel and plastic bag way to start seeds but for planting out into the garden I like making soil cubes. The cubes don't use a bunch of plastic or require the tedious fineness of moving bare root beets into soil.

Soil cubes need something to lighten them up a little otherwise you'll end up with compressed blocks of dry dirt akin to a brick. The mix ratios are not a touchy as the internet garden police make it sound but if you go too far off the rails the cubes won't hold together. The standard soil cube / soil block medium recipe is something like 2 parts soil / compost, 2 parts peat, 1 part sand and often adds some fertilizer. I'm ok with that but I hate the inefficiency of buying, moving, and storing a giant block of peat and would prefer to use what I had on hand.

The other thing I have been fighting is damping off - though it should be better in mid summer.

Today I did get things cleaned up and started the test.

The mixes:
A) 2 pts native soil, 2 pts peat, 1 part native sand
B) 1 pt native soil, 1 pt coconut coir
C) 1 pt native soil, 1 pt sawdust
D) 2 pts native soil, 2 pts sawdust, 1 pt coffee grounds
E) 1 pt native soil, 1 pt coir, 1 pt coconut coir

I planted half of each mix with beets and half with basil.

The sawdust used is from cheap pine being ripped on my table saw so it was more of a long strand than the fine crosscut sawdust off a miter saw.

The coffee grounds are used within the last two days and are the semi-cheap stuff I've been drinking lately - Folgers Noir dark roast.

The Coir was from a compressed brick.

 

[Tetters]

I for one will eagerly await your findings.
With the threat of peat being removed from our wish list here, I actually ordered a bulk bag of composted bark fines from a reputable firm here yesterday. Although nutrition and other material needs to be added for potting on, I know from experience at the nursery that this material is good towards rooting cuttings and growing seeds.
I'm unsure about including the native soil for propagation, and not all that happy about sterilising it in the oven or microwave as the temperature is seemingly all important Bagged soil starts getting too expensive - there is a limit! I have ordered perlite, hoping it will be a help with damping off.
@Mr_Yan what is the difference between coir and coconut coir?