It can be fun to breed your own zinnias

Hi all,

One of my hobbies is breeding my own zinnias, and I find that it is a lot of fun for several reasons. Zinnia breeding goes much faster than breeding most other plants. Zinnias can bloom in 6 to 8 weeks from seed and the seed germinate in only a few days. They come in a wide variety of colors, flower forms, and plant habits. So there are an almost limitless number of interesting crosses that you can make with zinnias.

They are relatively easy to grow, they grow fast, and they are easy to cross-pollinate. In many places you can get two generations in one year, so you could make your crosses in the Spring, plant "green" seeds from them in the Summer, and see your hybrid blooms in the Fall, hybridize them as you see fit, and save seeds from them before Winter to continue the process the following Spring. Or, if you are impatient to continue without a delay, you could grow those hybrids-of-hybrids seeds indoors under lights or in a greenhouse.

When you are breeding your own zinnias, you can cater to your own personal preferences. I happen to like zinnias whose flowers are rather "open", with petals not packed too closely together. This is an example of a zinnia that I chose as a "breeder" for that reason:

MM

Here is another example of an "open" flower form in a zinnia.

This zinnia has partially tubular petals somewhat reminiscent of a calla lily.

This zinnia has widely spaced narrow bicolor petals.

Some zinnias have a form with long rather straight petals that I refer to as "linear flowered". This example of a linear flowered zinnia appeared in my Burpee Hybrids bed.

I also like "toothy" petals like these.

I enjoy the interaction between my hybrid zinnias and insect life.

There are actually two small insects "hiding" in this bloom. It is a hybrid between two hybrids and inherits extra good petal texture and substance from one grandparent. You have to actually feel the petals to fully appreciate this property.

MM

Very interesting. I don't usually pay much attention to these. My mother grows them each year. Your hybrids are impressive. That is what it is all about making something new that you can enjoy. Are they true to seeds how do you keep from losing a cross?

BW,

"Are they true to seeds -- how do you keep from losing a cross?"

The hand-crossed hybrids do not come "true" from seeds, but instead a whole spectrum of variations appear as the hybridized genes recombine in many ways. However, you can "dehybridize" a hybrid by growing a lot of seed from it and by selecting only those recombinants that most resemble the parent hybrid. Many of our open pollinated varieties were produced by dehybridizing a hybrid.

It is not widely known, but you can grow cuttings from a zinnia. The cuttings come true, and they also give you a much larger supply of seed, which you can use to advantage in dehybridizing a chosen hybrid. The process of dehybridizing a hybrid is fun and rewarding, because in addition to the specimens that resemble your target, you also get a lot of new forms, including some that may actually be better than the chosen hybrid parent. That can give you the opportunity of creating several new cultivars from a single good cross. And, of course, there is nothing to keep you from making crosses between selected recombinants that can show up in the process of dehybridizing a hybrid.

This attached picture is a grouping of several zinnia plants that grew from cuttings from a single donor plant. I grew them last spring. It is a choice purple scabiosa flowered specimen. These plants matured to produce a "bumper crop" of seed that I can use to help stabilize a pure strain. It usually takes four or five generations of re-selection to get a reasonably uniform dehybridized strain. But since you can get more than one generation of zinnias in a year, the process can take less time than you might think. Dehybridizing does take some garden space, because it helps to grow several hundred plants to select from. I plan to use zinnia cuttings much more next year.

MM

This richly colored specimen produced very little pollen, so I used it as a female plant to receive pollen from many different bicolored zinnias.

This zinnia showed "wavy" edges on its leaves, so I chose it as a breeder.

This is the same "wavy" zinnia a little more developed.

Interesting so once you breed it back you can produce a stable hybrid? Something very close to the species but not exact? I know of breeding back to produce plants that are 99% pure from back breeding. My questions are mainly to understand why all the breeding if your hybrids can easily be lost or revert back to species. This is unless you are keeping a lot of your plants growing during the winter to keep from freezing out.
I would be interested in seeing your spectrum of seedlings and hearing what combinations you think have been producing the best results. I have always breed what I considered the best forms in my breeding or for certain traits, but back breeding has always interested me. From what I understand it is the breeding back to the parents that can produce the polyploid forms and many of the odd and unusual traits. I am not sure what the % of breeding the hybrid progenies of the same crosses is yet.
This unusual petal texture you talk about on one of your hybrids may be a trait or polyploid. Just today I was at a super market and they had forsale Amaryllis plants in flower. One had a tripple bloom. I had never seen this before so I went to look at it and it was very amazing. It was a polyploid the petals were extremely thick almost like leather the sex organs were all mutated but still very stunning.

Somebody mentioned this forum and glad they did. Didn't even know it existed.

Have abunch of hybridized " surprise" zinna seed I plan on growing out this season.

Love your pics and some of your forms are very interesting. Do you keep a record of all your crosses? Do you plan your crosses or are you just letting them be open pollinated?

Love your toothy look with the varigation in it. : ) And your purple with the insects hiding it it is stunning. Would love to see that one in person.

I have never tried to root a cuttign of a zinna before. How do you do yours.

BW,

"...so once you breed it back you can produce a stable hybrid?"

Not exactly. Stabilizing a hybrid (dehybridizing it) involves primarily selfing the hybrid, and not back-crossing it to either parent. However, all is fair in hobby plant breeding, just like in love and war. But dehybridizing is primarily a forward breeding thing, of saving seeds each generation from the plants that most closely resemble the good hybrid that you are trying to stabilize. If, in a successive generation, you find that you have several different plants that are pretty close to the "target", then it might be helpful to intercross them. But in no case are you trying to get back to the original species of Zinnia violacea, which is a rather weedy looking single purple wildflower.

"My questions are mainly to understand why all the breeding if your hybrids can easily be lost or revert back to species."

The primary answer to "why all the breeding" is that it is fun. There is a certain enjoyable anticipation waiting for a bloom from any mixed packet of zinnias to open up, to see what the flower will look like. The suspense is even more enjoyable when the zinnias are from hybrid seeds of your own making. The hybrids aren't easily lost. In fact, all of the commercial zinnias are either stabilized dehybridized hybrids, field-mix bee pollinated zinnias, many of which are hybrids that even the bees don't know the parents of, or commercially produced F1 hybrids from known carefully inbred proprietary strains. I doubt that any of us have ever seen an original species Z. violacea (sometimes referred to as Z. elegans), and even if we did, we probably wouldn't recognize it as a zinnia. It is kind of an urban myth that hybrid zinnias "revert" to the wild species. What actually happens is a complex recombination of genes, so that the results are best thought of as recombinants. They aren't reverting, they are recombining characteristics.

I will discuss the subject of "ploidy" in another message. It is hard for me not to get "long winded" when discussing zinnias. I am attaching a picture of a bicolor zinnia selected from Veseys Zig Zag strain. I like bicolors, and many of my hybrids involve bicolors.

MM

StarLight,

"Do you keep a record of all your crosses? Do you plan your crosses or are you just letting them be open pollinated?"

Yes, I do, in an approximate sort of way. I keep a garden journal, and record a lot of information in it. Each plant gets an identifying code. This year I designated my female "breeders" as B1, B2, B3, ... B70, B71, B72. Each code gets a brief description of the plant. There may be several male pollen donors, depending on my current breeding objectives and strategies. For example, one of my objectives is to get bicolored spider flowered zinnias. So bicolored breeders get pollinated with spider flowered zinnias or other good bicolors. Spider flowered zinnias get pollinated with bicolors. Sometimes, when it might not be "obvious", I make a note in the journal which male pollen donors were used. A female breeder can also be a pollen donor for one or more other female breeders.

"Do you plan your crosses or are you just letting them be open pollinated?"

I do plan my crosses and I prevent open pollination with the use of "hair nets", which I make from an open netting fabric that allows ready access to light and air flow, but blocks access to the flower by bees. Sometimes I will deliberately use a flower's pollen to self the flower when I think that is a good idea. The pollen donors also get protected by nets, because bees are greedy collectors of pollen.

"I have never tried to root a cutting of a zinna before. How do you do yours?"

The secret to rooting zinnia cuttings successfully is a product called Physan 20. http://www.physan.com/ The cuttings will usually rot from bacterial invasion without the Physan 20, because zinnia cuttings have soft tissue.

I also use a good rooting hormone like Dip 'n Grow, Hormex 3, or Rootone. All work well for me, although Hormex #1 is a bit weak, but Hormex #3 and Hormex #8 work fine. For treating a lot of cuttings at a time, Dip 'n Grow is a liquid that is convenient to dilute to the proper concentration. For treating just a few cuttings at a time, one of the dry powders is a bit more convenient. The diluted Dip 'n Grow should be used within 24 hours of dilution.

I use a sterile growing medium like Premier Pro Mix with added Perlite for better drainage. I root them under fluorescent lights. For the first week or so I keep the cuttings under a humidity dome. I usually use a 7-inch humidity dome for adequate clearance of the cuttings. After the roots begin to form, you can remove the humidity dome. I usually repot them for further growth into plants under the lights. I get close to a 100% success rate with my zinnia cuttings. If a cutting already has a bud on it, you should pinch off the bud. If it has leaves near the bottom of the stem, you should pull those leaves off.

I soak the cuttings for about 5 minutes in Physan 20, diluted 1½ teaspoon per gallon, to sterilize them. I water the rooting mix with a nutrient mix diluted ½ teaspoon of urea-free nutrients (I use Better-Gro Orchid Food from Lowes Home Store) per gallon and ¾ teaspoon Physan 20 per gallon. I usually prepare separate diluted solutions of nutrients and Physan 20 and then mix the two diluted solutions together. I saturate the rooting medium with that solution before inserting the cuttings. You usually don't have to add more solution until after you remove the humidity domes.

"Have a bunch of hybridized " surprise" zinnia seed that I plan on growing out this season."

Sounds like a plan. As they say on TV, "expect the unexpected".

As I said in the previous message, I like bicolored zinnia blooms. Most bicolors have a darker color at the base of the petal and a lighter color at the tip. But occasionally you can get the reverse situation, where the light color is at the base and the darker color is at the tip of the petal, like in this specimen.

MM

BW,

"From what I understand it is the breeding back to the parents that can produce the polyploid forms and many of the odd and unusual traits."

I don't think that is true of zinnias. As far as I know, there are only two commercial tetraploid strains of Z. violacea, State Fair and Burpee Tetraploids. If you cross a tetraploid with a diploid, you get a triploid. As a rule, triploids are sterile, in that they can't set viable seed. There are a few annual flowers that are deliberate triploids, because their inability to set seeds means you don't need to deadhead them. And you can't save seed from them, either. For example, I think there are a few triploid marigolds. Seedless watermelons are triploids. I don't know of any triploid zinnias. I seriously considered producing triploid zinnias, but I reconsidered because I wouldn't be able to save seeds from them.

I also considered producing additional tetraploid zinnias. But, referring to the book, Flower Breeding and Genetics, http://www.amazon.com/Flower-Breeding-Genetics-Challenges-Opportunities/dp/1402065698/ref=sr_1_1?ie=UTF8&s=books&qid=1228350255&sr=1-1 in Chapter 12 titled ZINNIA by Dennis Stimart and Thomas Boyle, it says "Relative to diploids, tetraploid zinnias have larger flowers and thicker, stronger stems but also have poorer seed germination, less branching, delayed flowering, and fewer capitula [flowers]. I considered that the disadvantages of tetraploid zinnias outweighed the advantages for me, so I gave up the idea of breeding tetraploid zinnias. That's not to say that others wouldn't enjoy breeding tetraploid or triploid zinnias. Just not me.

On a somewhat different note, I have enjoyed crossing Scabiosa Flowered Zinnias with "regular" zinnias. The disk florets of scabiosa flowered zinnias are not the usual yellow, furry stars, but are like little florets with the same color as the petals. The hybrids of scabiosa flowered zinnias with conventional flowered zinnias can produce some interesting results. Like, for example, this specimen.

MM

Another hybrid zinnia with one parent scabiosa flowered.

And another scabiosa hybrid, with a completely different look.

And another scabiosa hybrid.

Some of the scabiosa hybrids can be a bit "odd ball".

And some can have nicely ruffled petals.

MM. Siting here with the biggestest smile on my face and a light shining from with in the eyes. What lovely crosses you have made. : )

Your little scabiosa pom pom look is adorable.

Love the joy of seeing what hybridizing results bring forth. As you have pointed out, workign with Zinnas you can see your results alot faster.

Just for the heck of it, have you thought about trying to cross some of the spoon mums with some of your more open formed zinnias? Sometimes when I get out there to try and hybridize, I try and push the envelope with mixing different pollens.

Thanks for the recommending physan 20. I have not used it before , but definately going to order some, it may help me also with some other soft tissued cuttings that don't like to root easily.

When I get my Zinna crop up and blooming this year, definately going to ask you for evalutation and some hybridizing suggestions. I love to dab. Just hate when I get up at 4 in the morning to try an dbeat the bees only to find out they have gotten up earlier than me.

Besides a bunch of unknown crosses and I have a bunch of State Fair Seeds, California Giants, the Magellan collection and some other commercial seed I bought but can't remmeber the names of off hand.

The problem I have with Zinnas here is mildew. During the hottest part of of our summer the temps can get over 113F and the humidty is unbearable. Trying to find disease resistant cultivars is very hard.

StarLight,

I am glad to hear of your smile. The zinnia hobby is always about having fun.

"The problem I have with Zinnas here is mildew. During the hottest part of of our summer the temps can get over 113F and the humidity is unbearable. Trying to find disease resistant cultivars is very hard."

The Profusions, Zaharas, and Pinwheels are probably the most disease resistant zinnia cultivars. Unfortunately they aren't attractive to me as hobby zinnias because they are all members of the new zinnia species, Z. marylandica and the Marylandicas have limitations in plant height, flower size, and flower colors. (Marylandicas do get improvements every year, because they are commercially successful.)

However, my favorite zinnias are all Z. violacea, also known as Z. elegans, and they are relatively susceptible to a number of foliage diseases, including powdery mildew. Ironically, powdery mildew is probably the easiest to control of the various zinnia ailments.

There are a lot of mis-perceptions about mildew on zinnias. A lot of zinnias actually have mildew because their gardeners have been told that water promotes mildew on zinnias. The truth is the exact opposite of that. Mildew spores cannot germinate in water, and wetting your zinnia leaves can be an effective mildew preventative. In support of that assertion, notice that, in this National Gardening Association Q&A: Powdery Mildew on Zinnias, http://www.arcamax.com/gardening/s-1960-227172 they say, and I quote:

"Powdery mildew is unique among common plant diseases in that it doesn't require a wet leaf surface to spread. It can thus thrive during hot, dry weather, which is why you see it appearing in August. The general advice to inhibit the spread of fungal diseases is to avoid wetting leaf surfaces. In the case of powdery mildew, you can actually inhibit infection with frequent sprays of water. Also, examine plants frequently, removing any affected foliage immediately."

The underlining in that quote is mine. Frequent foliar feedings can also be a strong deterrent to mildew. So can sprays. A favorite of mine is GreenCure®, http://www.greencure.net/what_is_greencure.asp which is an effective control of a long list of plant diseases. GreenCure has several advantages over more toxic fungicides. http://www.greencure.net/why_is_greencure_fungicide_better.asp

Rose growers have a lot of disease problems, and many rose growers spray their roses a lot to keep them looking good and healthy. For me, my zinnias are my "roses" and I also lavish some attention on them, and spray them frequently, sometimes providing foliar nutrition, sometimes providing disease control, and sometimes combining both in the same spray. Incidentally, properly diluted, Physan 20 can be effective in a foliar spray. Not too surprisingly, I purchased my sprayer from a site that caters to rose growers. http://rosemania.com/shopsite_sc/store/html/index.html

MM

StarLight,

"Just hate when I get up at 4 in the morning to try and beat the bees, only to find out they have gotten up earlier than me."

I had the same problem for years. I decided to make "hair nets" to keep the bees from robbing my prime pollen. The nets can also be used to keep bees from pollinating prime female blooms. I make the nets from inexpensive net fabric that I purchase in the Walmart fabric and sewing section. I imagine that other fabric stores would have similar materials. I chose a net fabric with an open weave to allow good air circulation and exposure to light, while keeping the bees at bay. I found that the color black made the nets less "visible" in the garden.

I make the nets using sharp scissors or a roller cutter to cut the fabric, black yarn as a joiner material, a big needle to "sew" with the yarn, and a big needle threader to make it easier to thread the big needle. I alternate the yarn from the front to the back about every ½" to ¾". It's not necessary to make the stitches very close together. I suppose if you had a serger handy you could also use that to sew the nets. I have a serger, but it takes me quite a while to thread the thing, so I just use the knitting needle. I can make several nets in an hour.

The attached picture shows my current favorite net design, although I have used other more elaborate designs and a simpler design. Some designs are easier to make and some are more resistant to being blown off of the bloom in a storm or high wind. A design based on a tetrahedron with seams open at one vertex was perhaps the best at hanging onto the blooms in storms, but was also more tedious to construct and to install on a zinnia bloom. After a storm, I pick up any blown-off nets and re-install them.

The nets are quite effective against honeybees, bumble bees, and carpenter bees, even though the bottom is "open". The bees are quite impatient and don't search the net for a way in. They simply fly off to the nearest unprotected bloom.

For the most part, butterflies are not deterred by the nets and use their long drinking tube to reach through the openings in the net to drink nectar from the disk florets. Hummingbirds also frequent my zinnia patch, but I haven't noticed yet whether they sip nectar through the nets. I don't consider butterflies or hummingbirds a serious problem in my zinnia breeding. I enjoy their presence. It is a little startling when a hummingbird flies right by my ear. The whirring noise is loud. I am present in my zinnia patch frequently enough that the hummingbirds have come to ignore me, and will feed quite near where I am working.

MM

This is a simpler net design that a little easier to make, and works well enough.

This scabiosa hybrid resembles an Echinacea somewhat, so I refer to this zinnia flower form as echinacea flowered.

This scabiosa flowered hybrid zinnia resembles a marigold, so I refer to it as marigold flowered.

Another marigold flowered hybrid zinnia.

I am always looking for "toothy" petals, like this one.

More toothy petals.

Another marigold flowered zinnia.

Another scabiosa flowered hybrid.

And another scabiosa flowered hybrid.

StarLight,

"Just for the heck of it, have you thought about trying to cross some of the spoon mums with some of your more open formed zinnias? Sometimes when I get out there to try and hybridize, I try and push the envelope with mixing different pollens."

Spoon mums look great and I would love to get that look in zinnias. Many years ago I tried repeatedly to cross zinnias with marigolds, with the objective of getting the wide color range of zinnias combined with the nice foliage of marigolds. Suffice it to say, that didn't work. Zinnias and marigolds are not closely enough related.

Zinnias and spoon mums are not closely enough related either. I wouldn't be able to consider such ambitious crosses until I learned the techniques of genetic engineering, I would have to learn a lot of new stuff before I could do that. It is tempting to dabble in gene transfers, because it would be possible to get blue zinnias that way. That would open up a whole new world of possibilities. Like glow-in-the-dark zinnias, in all colors. Add a few bird genes and the zinnias could sing. But geneticly modified organisms are controversial, and for good reason. Because there could be unintended consequences and hazards of unknown magnitude.

For the near term anyway, I will stick with pretending to be a big bee in my zinnia patch. However, there are some interspecies zinnia crosses that I want to try next year. And I wouldn't rule out a few tissue culture experiments with zinnias.

MM

MM.. You've really got the cutting edge going on with your Zinnas. : )

The real problem I see with non relative crosses is how would you do an embryo rescue on the seeds? It easy to do with those seeds that make a seed pod and you can rescue the immature seeds before ten days is out and they usually start aborting, but can't figure out how in the world you could do it for zinna seed.

Are you working with all hubrids or do you have some species in their too.

Just thinking here. Depending on what genes you wanted to use. There some much DNA work that has been done on specific flowers now adays you might be able to do some research and find where somebody has already done the genetic coding for the part you want. Once you have it, you could probbably get somebody at one of the plant pathology labs to take that plant and code out just those genes to do the crosses with.

StarLight,

"The real problem I see with non relative crosses is how would you do an embryo rescue on the seeds?"

In order to save time, I don't wait for my hybrid zinnia seeds to mature in the Spring planting, and I harvest the seeds at an immature "green" stage and plant them. That can save several weeks and get the second generation off to an early start. However, planting green seeds isn't really embryo rescue, because in the case of embryo rescue, the embryos will not develop to maturity because of incompatibilities between the embryo and the "mother" plant.

None of the crosses I have done are "wide" enough to encounter embryo development problems. If I did encounter that situation, and I very well may encounter embryo development problems with some of my upcoming interspecific zinnia hybrids, then I would need to use tissue culture techniques to grow the embryos on a nutrient medium. I haven't done any tissue culture with zinnias yet, although I very well may try that in 2009. But harvesting the embryos could be done by cutting open the immature seeds in a sterile environment. I "help" some of my green seeds by cutting a slit in the green seed coat. That bypasses the wait for the still living seed coat to become water permeable by dying and, once again, saves a few days.

I am attaching a picture of some green zinnia seed that I grew this last Spring.

MM

MaineMan,

Once again -- gorgeous photos!! Congratulations!!

I grew some zinnias this year, but I was really too late getting the seeds in the ground. I spent too much time trying to get tomato and pepper seeds started. Next spring, I'll buy my tomato and pepper plants so I can get my zinnias in the ground on time. I did not attempt any crosses, but I did save the seeds from a number of them anyway. It will be interesting to find out if I have any accidental crosses in the bunch. I also ordered a lot of new seeds and have increased my zinnias growing area by about 300% over this year.

Maybe I'll have something worth seeing next year. LOL.

Karen

StarLight,

"Are you working with all hybrids, or do you have some species in there too?"

So far I have been using just commercial varieties of Z. violacea (also known as Z. elegans). Next year I plan to branch out to Z. haageana (Persian Carpets and Aztec Sunset), and Z. peruviana. The chromosome number is reported as 24 for all three species, which is necessary but possibly not sufficient for intercrossing compatibility. I am not depending on the interspecies hybrids for any quick payoff, and intend to continue my present hybrids between cultivars within Z. violacea.

"Just thinking here. Depending on what genes you wanted to use. There is so much DNA work that has been done on specific flowers nowadays you might be able to do some research and find where somebody has already done the genetic coding for the part you want. Once you have it, you could probably get somebody at one of the plant pathology labs to take that plant and code out just those genes to do the crosses with."

That approach is certainly worth considering. It is possible that within academia that some genetic engineering with zinnias has already been done. It probably would be possible to get the blue from, for example, Heavenly Blue morning glories, into zinnias, and those blue zinnias could be intercrossed with many existing zinnias to get many blue hues.

But there is a simple economic reason why we won't see those blue zinnias become commercially available. There is already a strong misdirected bias against any seed company that is even suspected of offering genetically modified organism (GMO) seeds. To my knowledge, no retail seed company offers GMO seed to home gardeners. But apparently many people believe otherwise. Most home garden seed companies have already been forced to publish statements that none of their seeds are genetically modified. Any retail seed company that offered blue zinnias would immediately be massively boycotted and their sales would plummet and force them into bankruptcy. The fear of "frankenseed" is widespread and deep. If blue zinnias are created, it most likely will be done by amateur hobbyists.

MM