In either case, once hermaphroditism has compromised the safety and purity of your sensimilla, the plant should not be propagated further. Remember, once a hermy, always a hermy. The plant pictured here is in the tenth and what should have been the final week of ripening, but a timer failed and one light stayed on continuously for almost two weeks, causing this vegetative regrowth. Because the light was continuous, the plant made no pollen. This method of re-vegging can be used to save a flowering plant you have no copies of, but be careful, as this may cause some strains to hermaphrodite.
Light poisoning refers to the flowering night cycle of a plant being unnaturally interrupted with light. The best way to prevent this is to close yourself inside your darkened room during the daylight, and then after allowing a few minutes for your eyes to adjust to the dark, check for any light leaks from covered windows, door jams, etc. Also cover all timer and appliance lights with tape.
Light poisoning is the most common cause for a normal plant to hermaphrodite.
Cannabis plants are monecious. This means they have the ability to be either male or female. Or in the case of hermaphroditism, they can be both. The reason to make sure there are no males or hermaphrodites in your garden is because male flowers make pollen. When pollen touches the white hairs on a flower, it makes a seed, and seeded weed gives you headaches. Even though there are reasons in nature hermaphroditism could be important, such as continuing the species in case there is no male present, hermaphroditism is generally a bad thing when talking about cannabis plants.
Negative stressors can combine with small interruptions of the light cycle to cause hermaphroditism, especially with less-stable, clone-only hybridized strains. When the night cycle is abnormally interrupted, it sends a mixed hormonal signal to the plant. This can cause a full female plant to throw some male flowers. Male flowers are easy to identify, especially when side by side with female flowers. Male flowers look like small bunches of bananas, which will take a week or two to swell before they burst and release their pollen.
Finding a hermaphrodite in your growroom can happen at any stage of the flowering cycle and is indicated by the presence of male flowers growing on the same plant as female flowers. As with all species in nature this can occur in varying degrees. A plant can become slightly or majorly hermaphroditic. In cases where singular male flowers are found between the branch and stalk nodes, you should be diligently removing them as they grow. You must re-inspect the plant top to bottom every few days to be sure pollination and seeding doesn’t occur. If you find male flowers (anthers) actually growing from within the female flowers (buds) the situation is a little more dire. You can still remove all the male anatomy as it appears, but it will be harder to find and much more prevalent. This is a horrible discovery that leads to a tough decision: Should you let the plant live and risk the whole crop being ruined by seeds?
Purposefully causing a plant to hermaphrodite is called selfing. Gibberellic acid or colloidal silver is typically sprayed onto the female plant. This technique is used to make feminized seeds and uses the plant’s ability to be both male and female to force a female plant to produce male flowers. The pollen contained in these male flowers can only produce female seeds. Just keep in mind that feminized plants should not be used for breeding, as they were produced without a true male, making them genetically inferior.
It is not recommended to spread fresh manure on fields if it is known to contain noxious or troublesome weeds. However, if producers need to graze before weeds seeds have been passed or if producers need to spread the fresh manure on a field, we recommend spreading weed seed-heavy manure on tame grass pastures or grass hayfields, because more options are available to control on them, says Miranda Meehan, NDSU Extension livestock environmental stewardship specialist.
To learn more about composting manure, view the NDSU Extension publication, Composting Animal Manures: A Guide to the Process and Management of Animal Manure Compost at https://tinyurl.com/NDSUCompostingAnimalManures.
“The manure, which includes feces, bedding and spilled or uneaten feedstuffs, should be kept in that area and composted,” Keena advises. “Composting manure has been shown not only to reduce the volume of manure and kill parasites and pathogens, but also is an effective weed seed management strategy.”
“The retention time of potential weed seeds in the gastrointestinal tract is heavily dependent on the digestibility of the diet,” says Zac Carlson, NDSU Extension beef cattle specialist. “When we turn cattle out to green, lush cover crop, the passage rate of that feed is high compared to lower digestible forages, such as prairie hay. That does not mean some seeds couldn’t get held up longer in the gastrointestinal tract.”
“If you have sent your cattle to areas where there are known Palmer amaranth, waterhemp or other noxious or troublesome weed issues, it will be important to allow a ‘cleanout period’ upon return,” says Joe Ikley, NDSU Extension weed specialist. “Crop fields are not the preferred area for this period, since weeds like Palmer amaranth are generally more difficult to control in crops compared to bare ground, pastures or a corral.”
Mary Keena, NDSU Extension livestock environmental management specialist based at the Carrington Research Extension Center, suggests confining cattle to one area for at least one week upon return.
“Livestock owners will want to keep a close eye on the area where the manure is managed to make sure escaped weed seeds that grow in the spring and summer of 2022 are pulled and properly disposed of,” warns Ikley. “Before the plants develop seeds, pull and destroy them by burying them deeply or burning them.”
Producers who have relocated their cattle out of state for winter feeding this year should consider having a weed management protocol in place when the cattle return, say North Dakota State University Extension specialists.
Keena adds, “If producers are going to spread the compost from that area, they will want to closely monitor the area where they spread it and practice similar monitoring and disposal techniques as in the feeding area.”
Polygonum cuspidatum goes by several other common names, including Japanese knotweed and fleece flower. Several other common names include the term, "bamboo," such as "Mexican bamboo." While its autumn flower does, indeed, look fleecy, "fleece flower" is just too dainty a name for so tenacious a weed!
Wild madder is, like sweet woodruff, in the Galium genus. Wild madder is also called "bedstraw." Apparently, people did actually once use this weed as a bedding material. Sweet woodruff is a creeping, mat-forming perennial that pretty clusters of white star-shaped flowers in spring and has very fragrant, lance-shaped dark-green leaves.
Wild Madder (Galium mollugo)
Being an annual weed, crabgrass perpetuates itself via seed—millions of seeds. To control crabgrass, you’ll need to address the issue in spring when the plant is at its most vulnerable. The best option to kill crabgrass is to remove the plants by hand, roots and all. After that, use an organic fertilizer to encourage the growth of lawn grass which will crown the crabgrass out.