Greenhouse Scout School 2026

Looks  like a saprophyte for sure.  If it keeps growing until you get actual mushrooms produced, and they are yellow, then it is probably Leucocoprinus birnbaumii, which appears frequently in potted plants.  The mycelium looks cottony, so I'm thinking that it is working up to producing mushrooms. See what happens.  And then pull them out before they mature to the point of having spores and spreading...they are a nuisance because the mycelium is hydrophobic, grows abundantly, and makes it hard to water the plants. 

Hi Tiffany!

It's nice to make a clean zone around the perimeter of your greenhouse...maybe 3 feet wide. This needs to be kept free from weeds, so you would probably want weed cloth under gravel.  That creates at least a little barrier to unwanted biology. But yes, you'll still get some varmints. Mice tend to come in to eat your newly planted seeds in spring. Does anyone have a good idea for barriers to keep them from getting up onto the benches? This is like squirrel management for your bird feeder! Make it a tight, snug house... at least for winter.

Cheers, Margery

Hi Tiffany, I have seen a lot of rodent/animal damage over the years - mice, moles (or voles?), rabbits, groundhogs, even foxes at one place although I don’t think they ate much, mainly just poked around in the greenhouses to see if anything interested them.  Many greenhouses employ IPM kitties to handle the smaller pests.

Sathwick,  There is nothing that will give you all the answers. If you identify your most important crop, and find out what are the most serious viruses currently affecting that crop, then in some cases you can go to Agdia, Inc and obtain immunostrips to test for those viruses.  With most ornamental businesses, your main interest would be INSV or TSWV - they are both really common because they are spread by thrips, which are very commonly problematic. It would probably not be cost effective for you to get additional tests to have on hand, because these tests, although quick, cost something like $12 apiece. If you have a non-resistant tomato crop, you might instead want to bring in TMV immunostrips.  If you specialized in petunias, you might also want to be able to test for TMV.  Rather than going this route, you could simply send a sample to Agdia for testing in their lab - more expensive, but they can test for many more viruses in one test, and give you a lot more information than the +/- for one virus that you can get from an immunostrip. Testing decisions are based on the value of your crop and the size of your greenhouse business.  For most growers who finish crops for final sale, I think it is fine to wait for symptoms and then ask the question of what virus is present, perhaps with the help of an extension person or consultant.  Other things can mimic virus symptoms, especially some nutrient deficiencies and herbicide injury.  It's generally too expensive to test a healthy looking crop just to see if there is a virus lurking within it.

Random thoughts in no particular order, hope this helps:  I am imagining that the person who wrote that was thinking of scouting a greenhouse of all one crop and probably one size of that plant - say a standard 6 1/2” poinsettias growing on benches.  So lifting up and scouting 10-20 plants per 1,000 square ft. would seem like a good amount to scout in the earlier weeks/months of the crop.  At each stop if I found an infested plant I would scout more in that same area to determine the extent of the infestation - so it would be only one plant inspected unless I found something on that plant - but maybe 10 plants scouted if I kept finding more pests.  In that case I would be marking off the area with flagging tape.  After finding several highly infested areas in one house there really is no point in continuing to scout that house - it needs to be dealt and me counting 5,000 more whiteflies isn’t going to make that happen any faster.  Conversely, if a house continues to be clean week after week and the cards are clean, then I would move more quickly through the house and probably lift up way fewer than 10 per 1,000 sq. ft.  Also, as the crop get bigger and there is more chance of breakage I would definitely pick up fewer plants.  There is a video of me in a house with very large poinsettias growing on the floor.  That house is probably at least 5,000 sq.ft., the plants were very clean, and VERY heavy.  I usually scouted about  15 of them each week.  With mum plants that big I would often just turn over leaves to check for spider mites and then shake some of the plants and sort of thump the plant down hard to see if any caterpillars fell out.  Depending on what the surface is they are growing on you can usually see the caterpillar frass, but knocking the plants dislodges the little caterpillars even before there is much frass.   So all the above would be for houses with mono cultures and medium to large sized pots.  If it was a mono-culture of something that has very few pest problems - say an entire house of petunias or an entire house of zonal geraniums - then I pretty much would just be looking for disease or nutritional problems and relying on the cards to alert me to any pests.  I would walk up and down every aisle looking at all the plants - looking for any signs of pest damage , cast skins, honeydew, etc. - but not actually lifting up individual plants  unless there was something like a yellow spot that needs closer inspection.  Ivy geraniums are a whole different story - they require very close inspection of the growing tips for thrips and later in the season spider mites.  The shaking thing is also good for Boston ferns & any ferns that get caterpillars. And then I also want to say that there is the ideal and there is the reality.  If a grower is paying you by the hour to scout you have to find out how many hours they are willing to pay for and then you have to complete the job in that amount of time.  They probably aren’t going to pay for you to find every last infested plant in the place.  Sometimes in my notes to the grower I would have to say “there are aphids in house four but I didn’t find the source”.   Yes I could have found them if I spent two more hours in there but it was probably more valuable to the grower if I got all the other houses scouted that week.  I may adds more thoughts later.

There are some predatory nematodes that attack plant feeding nematodes - although i don't know that any are commercially available.  More information on managing damaging nematodes than you probably wanted - https://attra.ncat.org/publication/nematodes-alternative-controls/#:~:text=Nematode%20control%20is%20essentially%20prevention%2C%20because%20once,matter%20to%20support%20diverse%20populations%20of%20microorganisms.

And i haven't heard of any dips that work for getting jumping worms off roots beyond water.

Thanks, Ana!