Tim, I've had mixed experiences with municipal compost. When I lived near DC, there was free "leaf mulch" they shredded in small batches and left at transfer stations. It didn't get hot but never gave me any trouble with trash, herbicides, weed seeds or pesticides. I tried municipal compost from a few smaller cities within about an hour from me before I found any that seemed decent. Lots of rocks and plastic; some of the composts I saw didn't resemble composted organic matter at all and seemed more like dredged river sediment. Used one city's compost that had industrial windrow machines and temperature logs and was happy with it for a few years before I got a batch in 2018/2019/2020 that contained high levels of an (aminopyralid?) herbicide, killing off thousands of square feet of garden that still not even weeds will grow in. Some of the tree service folks around here run their own composting operations, and I'd trust their stuff a little more with regard to herbicides but less with regard to temperature control. I don't currently mix most of my own potting mixes, but when I do I buy a lot of the raw ingredients from a local potting soil mixer (Dirtcraft Organics) or get custom mixes if I can get in on a group buy. Their compost comes from hospital food waste in Charlotte, the nutrient balances are good and the only weed seed I think ever came in through it was one productive and delicious tomato plant. As for rice hulls, I've been trying them for a few years after they showed up in Dirtcraft's seed starting mix. I don't repot often so I don't know if they'll last as long as my soil mix needs to, but Cyclamen have been happier in mixes with rice hulls than almost anything I've tried. Currently a lot (like 3x) cheaper than perlite here. I've seen a few nurseries using it as a top dressing for pots, haven't tried that myself. If anyone has info on rice hull/perlite replacement ratios I'd love that info! I've switched from peat to coconut coir to mostly composted local forestry waste for everything except carnivorous plants (and based on some advice from a local grower, I'll switch them to coconut as soon as this bag runs out), and it seems there's a shift from coir to more sustainable/local stuff like forestry waste, peanut shells etc as nurserymen dial in their formulae. Feeling the heartbreak of living in a place where 10,000+ acres at a time of Lilium, Trillium, Cypripedium etc. get destroyed by mountaintop removal coal mining, I'm trying to avoid using stripmined/rainforest deforestation etc. materials in my growing media as much as possible. -joe On Mon, Dec 18, 2023, 7:23 AM Tim Eck via pbs < pbs@lists.pacificbulbsociety.net> wrote: > Luckily they quietly took the bad stuff - arsenic - out of pressure treated > wood a few decades ago when a demographic study (of well water in Formosa, > I think) showed it was proportionally carcinogenic at all levels. Now, I > think, they only use copper naphthenate for fungicide in pressure treating. > Personally, I am banking on The American Chestnut Foundation (TACF) > eventually solving the problem altogether because chestnut wood seems to > persist untreated for decades in ground contact. > For those interested, TACF has withdrawn its support for their transgenic > chestnut, partially due to their dissatisfaction with the growth rate using > a constitutive promoter (always on) for the OxO gene (destroys oxalic acid > secreted by the blight fungus). But the departure from SUNY's deregulation > request was precipitated by the discovery of a misidentification of the > clone they were testing early in the program. TACF will continue > investigating transgenic (but with wound induced promoters) as well as > hybridizing and biocontrol. > If anyone is interested in breeding blight resistant forest quality > chestnut trees, I have (free) seed for the final generation of a breeding > program I have been working on for a few decades. The ideal plot would be > about two acres of well-drained cornfield. > Tim > > > On Sun, Dec 17, 2023 at 9:29 PM Laura Grant via pbs < > pbs@lists.pacificbulbsociety.net> wrote: > > > We had a bad experience with composted " pine bark" delivered by a local > > supplier. After most of the truck load was spread around the favorite > > plants we noticed some losses. When we came to the bottom of the pile we > > found labels that read "pressure treated". > > Laura > > > > On Sun, Dec 17, 2023 at 3:33 PM Jan Jeddeloh via pbs < > > pbs@lists.pacificbulbsociety.net> wrote: > > > > > I used to get tree trimmer waste at my old place. Some of those tree > > > trimmers also do some maintenance and I once got a load that that > wasn’t > > > straight trees. It was filled with crap from blowing off parking lots > > > etc. I learned my lesson. Always ask what’s in the truck before they > > dump. > > > > > > Jan > > > > > > > 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 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 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://…