Sadly there are some facilities that struggle with keeping out small bits of plastic and other debris. I expect municipal composting facilities have to meet the same standards across the country. It is worth asking. BTW, weed seeds also break down during hot composting. > On Dec 17, 2023, at 12:23 PM, Arnold Trachtenberg via pbs <pbs@lists.pacificbulbsociety.net> wrote: > > We had the company deliver a load of compost to our community garden and it was full of debris and garbage from street pick up. > I've never seen any lab work on the compost they sell. It may be tested different in CA, but not here in NJ. > I can imagine the petrochemicals, heavy metals and brake lining debris picked up when leaves are vacuumed up in the fall from our streets. > > > Arnold > > On Sunday, December 17, 2023 at 02:54:59 PM EST, Tim Eck via pbs <pbs@lists.pacificbulbsociety.net> wrote: > > Good point. I knew it got hot enough to kill most pathogens but was not > aware it decomposes pesticides. I rather doubt it destroys those > organo-halide bonds but they aren't so common anymore. > > On Sun, Dec 17, 2023 at 2:38 PM Nan Sterman via pbs < > pbs@lists.pacificbulbsociety.net> wrote: > >> Municipal composters all have to adhere to very strict ISO requirements >> and test regularly. They all hot compost and at the hot compost temps, >> pesticides and pathogens break down so they are not a concern. The testing >> is their - and you - assurance of that. All that testing is intended to >> ensure there are no problems with the municipal composts. I am actually >> more concerned about using compost from non regulated facilities like >> nurseries. >> >> Nan >> >> Sent from my eye eye phone. All typos are the captain’s fault. >> >>> On Dec 17, 2023, at 11:21 AM, Jane McGary via pbs < >> pbs@lists.pacificbulbsociety.net> wrote: >>> >>> As Mark mentioned, municipal compost in this area includes lawn >> clippings, and I don't use it either for fear of herbicide residue. I do >> use a mulch containing compost, but the company that provides it tests the >> ingredients for residual harmful chemicals. I like to use a minor >> proportion of organic material in bulb potting mix, and most recently I >> bought bags of "garden topsoil" from certified organic sources for this >> purpose. The main things I avoid are bark, which appears to be attacked by >> a fungus with visible mycelia that can also attack the tunics of dormant >> bulbs, and perlite and vermiculite, which have no value to the plants and >> tend to rise to the top; the latter are also said to be dangerous if you >> inhale the dust. >>> >>> When I started growing bulbs seriously around 1990, I had a country >> place with an alder woodland on part of it (alders are nitrogen fixers). I >> screened the topsoil to make up part of the bulb mix, along with ground >> pumice and coarse upriver sand. This worked very well and there seemed to >> be no problem with disease, even though the leafmold surely contained all >> sorts of microorganisms. I did not use this mix for seed sowing, but >> instead used peat as a minor component. I think sterilizing seed soil is >> pointless unless you can maintain laboratory conditions, since spores, >> etc., will arrive in the air. I used to grow Meconopsis by surface-sowing >> on milled sphagnum moss (not peat) as a preventive measure, but since >> moving to a place where that genus doesn't grow well, I gave that up. >>> >>> Probably the hardy, summer-dormant bulbs I grow are not as vulnerable to >> disease as the tropical and subtropical species some PBS members have. >> Surplus bulbs that I've removed to the garden mostly flourish there despite >> weekly irrigation in most places. It has always seemed to me that >> cultivating these plants as "hard" as they can tolerate results in >> healthier populations that appear in character. Coming to bulb growing from >> the perspective of alpine and rock gardening is no doubt an influence. My >> bulb house is very like an alpine house, but not even minimally frost-free. >> Many PBS members might despair at a situation where South African bulbs and >> tropical amaryllids can't be grown, but I like the relative freedom of this >> kind of gardening. >>> >>> Jane McGary, Portland, Oregon, USA >>> >>> >>>> On 12/17/2023 8:18 AM, Robert Lauf via pbs wrote: >>>> Regarding arborist debris, I'd be curious to know whether the kinds of >> bacteria and fungi inhabiting half-dead trees would present a problem to >> bulbs or if they are sufficiently host-specific that they are harmless in >> potting media. For all I know, they might be the same microbes working in >> composters. >>>> Any mycologists out there who could weigh in on this? >>>> Bob Zone 7 >>>> _______________________________________________ >>>> pbs mailing list >>>> pbs@lists.pacificbulbsociety.net >>>> https://lists.pacificbulbsociety.net/cgi-bin/… >>>> Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> >>>> PBS Forum latest: >> https://pacificbulbsociety.org/pbsforum/index.php/… >>> _______________________________________________ >>> pbs mailing list >>> pbs@lists.pacificbulbsociety.net >>> https://lists.pacificbulbsociety.net/cgi-bin/… >>> Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> >>> PBS Forum latest: >> https://pacificbulbsociety.org/pbsforum/index.php/… >> _______________________________________________ >> pbs mailing list >> pbs@lists.pacificbulbsociety.net >> https://lists.pacificbulbsociety.net/cgi-bin/… >> Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> >> PBS Forum latest: >> https://pacificbulbsociety.org/pbsforum/index.php/… >> > _______________________________________________ > pbs mailing list > pbs@lists.pacificbulbsociety.net > https://lists.pacificbulbsociety.net/cgi-bin/… > Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> > PBS Forum https://… > > _______________________________________________ > pbs mailing list > pbs@lists.pacificbulbsociety.net > https://lists.pacificbulbsociety.net/cgi-bin/… > Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> > PBS Forum https://… _______________________________________________ pbs mailing list pbs@lists.pacificbulbsociety.net https://lists.pacificbulbsociety.net/cgi-bin/… Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net> PBS Forum https://…