Chrysanthemum Production W21

Added: 2026-05-16

[00:00:00]okay so in this crops class we're talking about chrysanthemum production um chrysanthemums are found everywhere it's one of the most common uh cut flowers and potted plants i mean just think of fall moms or if you go to the grocery store or you look at your typical potted plant it's going to be a pot mom as we call it just because they're common doesn't mean they don't have their tricks and nuances to grow and also they are still a very much a profitable uh crop so let's dig into it so it's grown both as a potted crop right so that's you know in a pot uh as a weekly we call it ores the fall mum you know like large pots growing outside huge usually like hundreds of flowers on them or as cut mums you know it's probably one of the most common and least expensive cut flowers you can put in a bouquet so a lot of times they're used as filler they have good shelf life they have good color they're very striking so it's still a very significant industry um going back in the history of it it's actually originally from china the uh they've been growing for over 2 000 years at least that we know of uh and again with the uh the uh craziness of wooden boats going everywhere collecting stuff in the 1800s we brought chrysanthemums back to europe and they began to play and tinker with them creating hybrids and uh perennial and annual types and then by the time we hit the 1940s uh this is right around you know world war ii so it's always kind of weird to think that stuff normal everyday stuff was still going on during world war ii but believe it or not it was uh so they started breeding it pretty seriously especially in holland uh and and it's still bred to this day you know they come up with unusual flower shapes and colors and sizes i've just picked a few here if you go to dellaflore.nl you'll see hundreds of varieties that are that are bred and grown so for a potted plant we're looking for a well-branched variety right because each branch is going to terminate with a flower so the more branches the more flowers uh but we also need to breed it such that the branches can support the flowers uh oftentimes with fall mums we go so extreme on the the flower count that the weight of the flowers can't be supported by the branch and they they snap off when you go to pick the plant up we often breed in mildew resistance uh mildew is something that is a continual challenge with chrysanthemums and so we try to build resistance uh genetically into the plants and of course they're always breeding for lots of different colors as a cut flower we're looking for really really good flowering characteristics we don't care so much about the stem because we're going to shape that thing we want good color color that doesn't fade and good shapes and then of course flower life is important as far as growing let's talk about producing a pot plant first then we'll discuss a cut plant and then we'll go into some of the diseases and whatnot but so for a potted plant or potted chrysanthemum uh particularly a fall mum right that's sort of in ontario the biggest most common industry um we typically stick our cuttings in june it's quite early you know we're talking fall it's a fairly long crop you can use a simple number one uh rooting compound it's a vegetative cutting it doesn't need a lot of hormone fairly warm temperatures 21 to 22 degrees celsius with high humidity this is where tenting is often done uh with mumps stick the cuttings on a bench put a dome over it cover with a a plastic layer to keep the humidity in and a week or two later it's done uh this link if you go to your powerpoint version of this lesson that link is active i suggest you look at it i've got a bunch of other videos that are really interesting to watch you should see how sophisticated mom production has become with robotics and and using intelligent imaging and automatic transplanting it's it's wild but big business so some growers in weekly programs actually stick the cuttings directly in a pot if you're going a four inch five or six inch pot they would just usually stick the cuttings directly into the end pot uh and even with pot mums or fall mums with larger pots they sometimes direct stick it depends on the variety and your space you know what you have to root it out right can you can you properly root that many pots or is it easier to do plugs and then transplant so it depends on your facility but direct sticking is definitely done uh you know with smaller weekly pots when we talk about weekly we're talking about those grocery store pots with your standard pot cover your 3.99 or 4.99 potted flour uh thing you see your any any old grocery store uh typically after a transplant and they've grown for two to three weeks the plants have established at that point we pinch right so in this picture you'll see there's uh one two three four and five apical meristems five cuttings have gone into that six inch pot and here the person is grabbing the apical and pinching it off so it's removed and why do we do that because we get way more lateral branches and more flowers it gets bushier and produces more flowers so you know for your five cuttings instead of terminating at five flowers they would produce maybe 15 flowers because each stem would then have say three flowers so pinching is critical with chrysanthemums and it is for the most part done by hand unlike hydrangeas where they just mow it because the harsh cutting of a leaf like maybe not perfectly off like cutting leaf in half doesn't matter because with the hydrangea you're gonna put that plant into the cooler and knock all the leaves off because you want it to branch in the field before you bulk it up whereas with the mum there is no winter treatment there's no vernalization we're pinching and then we're selling so we can't just you know mow it with a lawn mower even though that would work but all the leaves that got cut harshly would be ugly and might invite disease or pests and here you can see the part they've pinched off the pot leaving the the apical meristems have been removed right and when you remove an apical meristem we remove apical dominance and so with this gone all the lateral branches start to grow so each one that you take off lateral branches form and they always terminate with a flower so here you got a flower you got a flower and you got a flower and you got a flower instead of two we have four so pinching is really critical um now as far as pinching goes there is in recent years geneticists have bred into especially phalm varieties because there's so many and there's so many branches they have bred in what's called automatic uh uh self-pinching and what happens essentially is that the terminal bud on each stem is programmed to abort so the fall mom grows and then the apical meristem self-abort and then they create a they break that apical dominance so that's a pretty pretty fantastic labor-saving um feature that fall mums have produced and they have they're so efficient at self-aborting that you know fall moms like this they just turn into a giant hugely branched with hundreds of flowers i mean it's astonishing how well it works so as far as the scheduling goes there's 8 and 15 week type [Music] mums you know eight weeks from transplant to sale date most growers grow the longer ones especially for fall moms with your weekly program you might go more with the the eight weeks variety to keep things turning but most people in the future in the fall one use the longer varieties and one thing that's especially unique about chrysanthemums is that they are a short day flowering plant that's originally how they turn into a fall mum right because it was inexpensive to grow but you could only get it to flower in the fall if you didn't have equipment so remember a short day flowering plant needs what to flower it's always opposite so if it's a short day it needs a long night right so a short day means it needs a long night and remember the plant measures the night not the day oftentimes you get confused by that the plant measures the night length not the day length so a short day chrysanthemum and you look at this picture this is the night component it's dark this we get flower forming if the day is longer then we get just vegetative growth right uh now one other trick which is used in chrysanthemum production a lot is that let's say you're in the middle of the winter but you don't really want it to flower not yet all you do is turn a light on in the middle of the night and what that does is it splits the night so obviously you put the light on in the middle of the night and that means that you've got a short night here and you've got a short night here so you've got two short nights and what does the plant see it only ever sees a short night this light in the middle of the night disrupts it so it sees a short night no matter what we do which means it's going to stay vegetative and remember that because that's really important for different ways of growing chrysanthemums that we'll talk about in a minute so for fall production right natural lighting is sufficient because the days are getting shorter and the nights are getting longer but if you're doing weekly sales pot sales pop mom sales right every week of the year what are you going to do in the summer you have long summer days what are you going to do so you use blackout and you black out your greenhouse now that can get real tricky if it's hot right so obviously that happens at the end of the day but heat is a challenge for greenhouses producing the summer fortunately sales for potted mums are not very strong in the summer so some farms quite a few just sort of stop through the summer and then they pick up again in the fall and there's a period of time where they don't really need night interruption because the nights are long and then when they get towards spring they start using blackout and it's not as hot so it works and then when they get to summer again they sort of pack it in so typically a mom needs 12 to 15 hours of darkness in order to flower so that's where your blackout comes in uh in in once you're say you've grown your plant it's vegetatively been growing you need about four weeks of blackout to set buds to get flowers to start you know so a 10 week mom remember there was 10 8 week to 15 weeks so a 10 week mom you would initiate short days after six weeks of growth from transplant so i'm not going to get into detailed scheduling because there's so many varieties and so many different strategies so that kind of stuff is on your grower data sheet that you'd look at when you buy a particular variety but you need four weeks of blackout so remember that in order to set buds if buds were to appear prematurely for some reason right something went wrong uh you can actually remove the buds and then actually feed extra nitrogen which would steer the mum towards vegetative growth you can kind of push it back into vegetative growth uh and and buy yourself a little more time if it somehow started flowering early so typically knight interruption is used even if your nights are long it's sort of like insurance you know they may run the lights depending on the time of year for anywhere from you know half an hour to four hours but usually they're running it for a couple hours at minimum and you don't need a lot about 20 micro moles right so here a string light is literally all you need we're not growing the plant we're not running photosynthesis all we're doing is messing up its uh its hormones so that it perceives that the night has ended okay this graph is showing us how the day length throughout the calendar year for our area and obviously you know december january are the shortest days of the year so as far as your night interruption if you're anywhere from october to march so through the dead of winter we use about four hours of night interruption if we're trying to maintain a vegetative state april to may you can use about three hours of night interruption and then through the summer three hours and getting into uh the dead middle of summer june july you only need about two hours so it ranges from two to four hours of night interruption to keep the chrysanthemum vegetative okay now of course november to february you don't need an interruption if you're trying to flower right um so if it's 12 to 15 hours are needed why do fall mums initiate flowers in the field in the fall so remember this is a field production there's no greenhouse there's no blackout blocking the sunlight and yet chrysanthemums still kind of set bud and flower in the fall right they don't have 12 hours of darkness in october so there's something else going on right um what's going on is that chrysanthemums are actually thermomorphic we've learned that already in another lesson so on top of being photoperiodic where we use night interruption to guarantee that it won't set bud if we're trying to encourage vegetative growth they will naturally start to flower as the day lengths are shortening but the big thing is that your night temperatures start dropping around 10 to 15 degrees celsius that's fairly cool that's why they're called fall moms right so when the fall comes and nights are cooler that actually has a bigger influence than photo period in terms of setting flowers so you only need a few days of cold right so if you had a weird cold front come in your mums would actually trigger flowering early so what are the growing needs for chrysanthemums like many things never let them dry out now some plants can handle it but chrysanthemums do not they drink a lot of water if you're growing potted mums in the field they get watered every day quite a few times a day they drink a lot if you let them dry out they'll flower earlier from stress which is common but you'll get less branching so it'll be a thinner stretched out plants undesirable a mature 10 inches 10 inches sort of your typical fall mum can consume up to two liters of water per day that's a lot per plant just think about that a couple of bags of milk worth of water going in there every day each pot you need a lot of water um feeding every five days so it's not every day you don't feed every day your salt levels go through the roof and the root zone but every fifth day we're gonna feed 250 ppm nitrogen remember we always look as growers we look at the ppm or the millimole nitrogen requirements that means that the other nutrients follow according to the ratio of the fertilizer that's recommended so if it's 250 ppm nitrogen that means we're asking for 250 ppm potassium because it's the same but we're going to ask for 125 ppm phosphorus because it's half the percentage so that's sort of a typical chrysanthemum feed 20 10 20. um calcium is critical a lot of growers go with a calmag special mix which has calcium magnesium added not all the time though if you don't have enough calcium your branches are weak and the branches will snap especially when the flowers get wet when it rains or wind blows on your outdoor crop the branches will stress and snap off because of all the weight so typically a calcium nitrate shot is rotated in with your 20 10 20. just straight calcium nitrate that gives the shot a shot of calcium for those those mums to have a strong stem ph is normal for a potty crop remember this is not hydroponics this is potted stuff typically a higher ph in the root zone so a six to six and a half um as far as the media goes one interesting thing about chrysanthemums is that they are almost always grown in a peat mix that has compost which is really interesting not many potted plants use that i i like it but not many growers use it because they're worried about you know fungal infection or holding too much water but 20 to 25 compost gives extra nutrients uh it improves moisture retention remember mums need a lot of water uh plus you get some minor nutrients right like uh micronutrients and even nitrogen coming from the compost there's also benefit from bacterial populations in there that we you know help break down nutrients and make them available to the plants and also a beneficial fungi so it's it's a common thing to have a compost mix uh you know most media growers supply what's called a mum mix which has that compost in it it also has a higher cation exchange capacity which means that your nutrients don't leach out as much and remember you're doing a lot of irrigating and you're growing out in the field and it might pour rain in a rainstorm one day you don't want all your nutrients to leech out of the soil so that compost helps hold on to the nutrients you've given so that's there's a bunch of pluses plus you have extended shelf life when you send it to the store because the compost holds onto nutrients they're all win-win wins right um controlled release fertilizer is something that is commonly used with mums uh this is a a kind of nutrient that is inside a coating now there's two different things there's prilled fertilizers and there's controlled release fertilizers you should know the difference a prilled fertilizer is like a pelletized fertilizer like a like coarse salt it doesn't have a coating it's just in chunks which means that it takes a little longer to dissolve whereas controlled release fertilizer is fertilizer that's sort of in chunks but then it's coated with a biodegradable film and that film helps control the release of the nutrients um typically the way it works is that you mix it into your media you can put it on top there's a risk that it will fall off if the plant rolls over sometimes you can incorporate into the media when you mix it but often it's just placed on top and then whenever you water the crop whenever water washes over the crf it will actually move through that coating and displace a little bit of fertilizer into the water as it moves over it so that's why it's called controlled release the other thing that happens is temperature also impacts how much fertilizer is released uh it's typically sold in different lengths of duration so anywhere from three months to six months is how long the crf will last actually you can hit one month too that's just the thickness of the coating that goes over the crf but typically around the base of the plant uh you want to stay away from you know direct sunlight if you can because that the heat uh will increase the rate of nutrient release and of course every time it rains the water moves over the crf and releases nutrients so it's it helps feed your crop in a controlled manner whereas a prilled fertilizer it does dissolve fairly quickly you don't control it as much as the crf commercially crafts the the major brand is called osmocote because it uses osmosis for water to move through that coating [Music] so yeah when the temperatures are warmer nutrients are released more quickly but they need temperature and moisture to release um yeah so leaching if you don't have enough leaching you might get salts but you know usually you keep an eye on your salt levels as a grower do a couple of pour throughs here and there if your salt levels are building up then you would water a couple of times clearly heavily with clear water you might still leech from the crf but you'll be displacing the high salts out of the bottom of the pot let's talk about cut mums for a second a couple of pictures here from cut mom greenhouse notice they've got blackout right because they're going to control the photo period uh lots of different types of cut mums this is another picture showing cut mums being harvested in the greenhouse so they're done year round and typically we want a tall plant right and either we want just one flower or we want a few flowers at the top okay so i've got here we got one bud setting and here we've got you know one two three four five buds setting there's this subtle difference here um if we're going with just one flower with the cut mum production what we do is we dis bud which means the staff go through and they pull lateral buds off the stem and that does a couple of things right they leave the apical bud but they remove the others which means all the sugars and nutrients that are being produced from the plant that are moving up will feed the main flower that's left and you end up with a much much bigger flower because it's not competing for nutrients with the other bud sites these are called disc bud cut mums so it's typically a law a tall stem with a giant flower at the top these are just a couple of examples of genetic varieties these are three groups of three stems so here we got a green one and we've got your classic yellow mums just one if you look at the stem there's no flowers and then there's one flower at the top so those are disc buds if you go to what's called a spray yeah i know this is a poor image here it's what i could find a spray is a tall plant but it has a few flowers at the top so you leave some lateral branches you may disc bud a few down below but you leave a few branches near the top and you get quite a few flowers so for one stem you fill out a bouquet but the the flowers are smaller right that's the trade-off so usually growers grow a combination of disc buds and sprays depending on what their customers are looking for and these are some examples these are again these are groups of three stems and look how many flowers there are just on three stems so sprays have quite a few more flowers but they are quite a bit smaller in size so how do we grow such a tall mum right it goes back to the blackout that i was pointing out here in this picture so what the the growers do depending on the time of year if it's a time of year where they need to prevent it from flowering so uh you know we're looking remember chrysanthemums flower when it's short days right so we may we may want to use the cloth if we're trying to encourage them to flower or we may not so we want to basically what we do is grow the plant and keep suppressing flowers keep growing it keep growing it keep suppressing flowers so long days so how do we do long days we do what's called night interruption right we run those light bulbs over the crops in the middle of the night from anywhere from two to four hours to prevent buds from forming and once the plant reaches a certain height in this case about 90 centimeters then we turn off the midnight interruption and we encourage flowering and sometimes we even have to pull the blackout cloth depending on the time of year so if you're trying to flower chrysanthemums in the middle of the summer then you need blackout because you need to shorten the day right and you need that long night so blackout is really important for using producing cut mums in ontario where we have long days for uh you know over half the year right so typically this is the sequence we maintain a long day or use night interruption to keep the plant vegetative once you've received the desired height we move on to the next state right so also while we're at this stage we keep the night temperature close to the day temperature and that also encourages vegetative growth and while we're doing this while we're growing the mum taller we may remove axial branches and buds to shape it then we move on to flower induction right so start our blackout and get the flowers forming and we continue to remove axial buds while the plant starts to flower that's if we're making a a disc bud and for a spray you may remove some of the lower ones but typically it's grown tall enough that you just leave for the most part leave them all and you get your spray as far as pests for chrysanthemums it's the usual suspects except maybe leaf miner it's it's a favorite of leaf miner if you ever see these white tracks these tracks that's leaf miner they are a bit of a pain to control your ipm people have taught you some of the the beneficials that will go after leaf miner but they're definitely a problem this is a parasitic wasp laying an egg in a leaf miner i think it's diglyphus it's a fairly effective but you got to use a lot of them remember some of you i talked to about the mullein plant that is used to maintain diglyphus uh a lot of mom growers use those these flying wasps that will try to control your leaf miner but when you have leaves that are this unsightly it's hard to sell your your fall mama you probably have to throw it out so now these little larva that hatch and then they crawl between the upper and lower epidermis of the leaf if you can see where they start it's small and as they grow they get bigger and bigger and bigger and the path gets wider and wider until it's fat and then they cut a hole and they emerge and they drop down to the ground where they mature in the soil and then they turn into a flyer that goes and lays eggs again they are really challenging to control but it can can be done there's also the hoverfly here uh but whatever it is a it is a pain they're they're very destructive as far as fungal infections uh botrytis is a possum is it fairly common in mums especially in the fall when you get a lot of water sitting on your crop so you gotta watch for that uh bacterial leaf spot you get these dark spots that form randomly on leaves and remember they're usually not symmetrical if it was symmetrical and on both edges we would think more nutritional right but they are usually in blotches that's your bacterial leaf spot if you start seeing wilting or curling now this picture i guess i should assume but you can see the leaves kind of had a little bit of a curl at the new growth near the apical meristem this is a sign that we're not getting enough water up the vasculature to help the new growth expand and that's usually a sign of either pythium or fusarium something's in the vasculature stopping water from flowing and so you get that that will so if you look for curling and wilting then you know you have pythium or fusarium pythium we know how to diagnose because we would take the plant out of the pot and we would look at the roots right and see if they slide off their steel this is an extreme example obviously this is beyond salvage that's when you have let it go too long so oftentimes drenching with fungicide is a preventative there's a lot of beneficial fungi like actinovate we've discussed this in other classes that are effective at preventing fungal infections but if you have an outdoor fall crop you're subject to mother nature and you may have a really really wet fall and it can prove devastating to your crops so you're at the mercies of mother nature when you grow outside white rust which is a controlled disease if you get it in your crop the cfia will remove your crop at your expense so you need very you need to be really careful you don't get this if you do you got to clean it up right away they look like white crusty pustules underneath the leaf and on the top side it looks like a green gnarly raised crown it is uh it is a serious risk with mums it's a it's restricted they're trying to keep it out of our country uh i haven't seen it myself although growers have run into it so it it typically means you got to start with good material you know if you keep taking your own cuttings all the time not so good you got to you got to buy cuttings from a reputable supplier a clean certified supplier uh you need to keep your your plants spaced let air flow no touching uh typically you don't water at the end of the day because you're gonna get standing water that lets spores germinate uh there's all the usual suspects for preventing a fungal infection now like powdery mildew it requires a living host so if you clean properly between crops there's no reason for that disease to carry over to a new crop there is the chance that nearby daisies like wild daisies or marigolds can host it uh they're compatible so be careful about what's grown around your farm viruses like all plants chrysanthemums are susceptible it even has its own very own virus named after it but this one will also affect other plants but chrysanthemum mosaic remembers the mosaic so it creates interesting what we call mosaic patterns in the leaf that's how we identify it as a mosaic they could be concentric rings but they're usually patterns of some sort that make the leaf look almost variegated another one is impatience necrotic spot virus and it really is literally that you get small lots of necrotic spots this could be challenging to identify because you want to look for it not commute confusing it with nutrient deficiencies and this is a really good example here because we see it on this side right but we don't see it on this side so again the symmetry symmetry is what helps give us clues as to whether it's a nutrient problem or a viral or fungal so look for that you know symmetric symmetry keep saying that look for that lack of or symmetry across the center blade of the blade to give you some clues uh and then of course uh mum a tomato spotted wilt virus is another one this again would be difficult so here's a leaf right we're looking at the middle of the leaf and here's some necrosis on the edge do we see it on this side no we see it on only one side so that's going to tell us that we're looking at either a fungal or a viral infection and remember the only way we can truly identify a virus is using an um an antigen test those agdia tests where you take a leaf mash it put in a tube drop a stick in and then you look for a color reaction and that tells us if it has the virus or not um here you can see that apically there's green leaves on this but below it there's yellow leaves and then there's green leaves again that's that's also not typical for a nutrient deficiency so again you'd suspect that it's viral oh that brings us to the end of chrysanthemums um it's a quicker lesson but uh covered some interesting stuff we discussed yet another photoperiodic and thermomorphic crop and we talked about how to grow cut versus potted with disc budding and using photo period to control stem length for cuts so a lot of interesting stuff there okay