Specialty Gardening: Why not add pine bark to soggy dense seed-starting mix?, 1 by tapla

tapla wrote:
Pirl - yes ...... that 'over-nurturing' of a new plant, especially by new or inexperienced growers, can sort of end up being like 'killing them with kindness'. Most of you that know me, know I think that how well your soil is aerated when you established a planting, and how long you can depend on that soil to remain well-aerated, are the most important considerations when establishing a conventional container planting.

Thanks, Rick. I try to qualify what I say as I go. There are plenty of 'one size fits all' statements we CAN make, but there are lots more commonly made that need qualification. I find that most arguments arise when one person says something without qualifying the information - someone notices and corrects or qualifies - then we're off to the races because some one's ego got bruised. ;o)

I'll try to follow your post with my comments, so you might need to scroll back & forth to see what part of your post my comments are directed to.

If you're unsure of the pH, don't just guess that it's low. Add your 1 tbsp of lime per gallon, or 1/2 cup/cu ft as a starting point. A pH too low is probably better in containers than one too high. More on that if you need it.

If there are any issues with a bark product, flushing will remove some of the toxins, but composting & turning will do the job faster. Personally, I've never run across a problem with a conifer bark product, but I do know that entities that make their own soils occasionally reject loads of bark for the reasons I mentioned. I just wanted you to be aware of the issue in case you mix up a bark media & find it lacking. The natural tendency would be to blame method rather than the influence of toxins. Like Polly, I've started lots of mainly cuttings in bark-based soils (and the gritty mix) with great results. I'm not big into seeds, but there's not much difference - both cuttings and seeds love a coarse medium with lots & lots of air in it.

If the bark you have is going to have a problem, I would expect it to be wet - maybe turning black where it's wet. Dry (in the bag or when you receive it) bark is very unlikely to present problems. Try not to make too much of an issue that probably isn't there.

Watering technique is a very important part of container culture - much more important when the containers are shallow or the soil is heavy. The margin for error increases dramatically as the soils PWT approaches 0 or is 0. Ideally, you want to be able to water copiously enough that 10-15% of the water you apply exits the drain hole .... every time you water. If you cannot do this w/o risking a negative impact on root function/metabolism, you're leaving potential growth/vitality behind, often a very significant amount. The air:water relationship of soils, including the accumulation of soluble salts is very often, if not usually, more responsible for decline/death of houseplants than lack of light.

Turface isn't coarse enough for seed starting unless you screen it. It holds too much water when unscreened. Perlite the size of BBs (or larger) is a good medium for seeds & cuttings. I don't like sand in soils unless it's at least half the size of a BB - more like fine gravel. Think 'aeration'.

Capillary watering is ok for the short term in the right soils, but promotes a build-up of solubles over the long term. I like to top-water seeds & seedlings to 'moisten' the soil. Then use a wick & tilting the container to drain any excess water (from the PWT).

If you do use a spritzer - try not to wet foliage. Many fungi need a period of wet/moist conditions, or conditions of near 100% humidity for incubation. The period needed varies by fungi - but don't give any of them what they need to get a hold. Spritz soil - not leaves.

Al