5:1:1 questions

2 years ago

last modified: 2 years ago

Okay, so I am biting the bullet and ready to move towards the light.

My motivation- I have had petunias and snapdragons (mostly and sometimes other plants) succumb regularly to verticillium/fusarium wilt during the summer. Some survive and live for several years as perennials (indoor/outdoor rotation) but most don't. I have also had a hard time with Dahlias, one year it was broad mites (they also infected peppers, stocks, torenia...) and another year it was root rot. I am not too concerned about potting media for house plants or bigger plants outdoors like roses or clematis (for now) but need improvement in the mix for the smaller ones that go into railing planters and such.

Also, I finally found what appears to be a good source of pine bark at Lowes in Gardenpro pine bark mini-nuggets (at least for now). I first got the Timberline pine bark mulch because it is all that is available locally but quickly realized (for the second time, I tried about 3/4 years back, somethings never change) that there is no pine bark of any kind in it (see pics). I am amazed why Timberline hasn't been sued out of its existence for such outright misrepresentation of its product.

Anyhow, I have a bunch of questions:

1. The pine bark and perlite are both fairly light. In one way, it is good that my railing planters will be much lighter and I can put more media in them. OTOH, my balcony is super windy at least during spring and fall and I am worried that the wind may just uproot and take the plants with it if they aren't sufficiently tightly anchored in the growing medium.

2. Lat year I bought several roses, a camellia and a schefflera from lowes and they were all potted in what appears to be just plain pine bark. (small size). I can't see any perlite or pumice for sure. There is not much discernible peat either. Any idea how they manage to do this?

3. If I am using the 5/1/1 for gardenia or camellia, should I reduce the lime so they have a slightly acidic medium and I don't have to feed acidic fertilizer or water with vinegar to keep them from yellowing?

4. Below are the pics of pine bark mini-nuggets and perlite. I have separated fines by sifting to show their amount in proportion to that of the other sizes and also separated the bigger pine bark for the same purpose. Question -can I get away a) with not sifting the pine bark and/or the perlite for fine/powder; b) leaving the bigger bark in there? Basically, can I just mix them as is and use it as such, possibly by skipping the peat altogether?

5. If the mix is going to be too fast draining can I use 4/2/1 instead (two parts peat or just one part peat and the fines/powder from bark and perlite work as equivalent to another part peat?

6) Am, I correct in presuming that no matter how much I mess up by not sticking to the exact size and ratios, the ultimate result will be better than off the shelf potting mix (MG/Sta-green) mixed with perlite (5/1 or 4/2)?

7) Are the lime pellets (Epsoma) to be mixed and the mix watered and left alone for a couple of weeks? The bark is moist already. Photos to follow.

Featured Answer

gardengal48 (PNW Z8/9)

2 years ago

"My question is, how is the one part peat better than the removed small particles of bark?"

That's a valid question and I don't have the answer. I've never had much dust from my bark or even much need to screen so never really paid that much attention as to whether one could substitute freely for the other. Might be worth an experiment :-)

ZM, acidifying with vinegar water is a pretty common practice for those who like to grow acid loving plants but whose irrigation water is alkaline. It's a pretty dilute solution - a tablespoon of table vinegar to a gallon of water - and is harmless. Vinegar can act as a herbicide but it needs to be of a much higher concentration (even undiluted table vinegar is only marginally effective), must be sprayed directly on the foliage and it must be applied with direct sunlight to generate the phytotoxic reaction that kills the plant. Or at least the foliage - roots are rarely damaged.

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