Being one of the easiest cut flowers to cultivate, they are a perfect first crop for beginning growers but also serve as a steady stand in on almost every thriving flower farm I know of. We’ve been growing zinnias since the beginning and every year I fall more and more in love with them.
Like almost every other flower in our patch, we work hard to treat these guys as well as possible from day one. Before planting beds are given 3-4″ of compost, a light dusting of rock phosphate, a little lime and a big dose of a general organic fertilizer (Nature’s Intent 7-2-4).
This mix is tilled into the soil and then four lines of drip irrigation are laid down, roughly a foot apart and then the beds are covered with a layer of pre burned landscape fabric. Plants are spaced 9×9″ apart with five rows per bed and our standard seventy foot beds hold about four hundred and fifty plants. Originally we were worried about the tight spacing but they seem to like it just fine.
I know many growers in warmer parts of the world that are able to successfully direct seed their zinnias straight into the field but here in cool Washington we start our plants four to six weeks before setting them out. Zinnias resent cold weather and really prefer to be planted after things have warmed up a bit. Seeds are sown in 72 cell trays and planted out two to three weeks after our last frost date. Here they usually go into the field around mid May.
After the babies are snuggled into their permanent homes, we give them a twice monthly foliar application of compost tea (with fish and kelp) and weekly waterings through the drip lines. When plants are about 18″ tall we go through the patch and snip out the center flowers. This technique is called pinching and while is feels pretty counter intuitive at the time, it will encourage plants to begin branching low and ultimately produce much longer stems.
Johnny’s Select Seed is my favorite source for seed. They carry all of the great ones including the monster Benary Giant Series, the Giant Dahlia Flower Series, the bi-color Zowie, the massive magenta Uproar Rose and my personal favorite, the adorable Persian Carpet mix.
I’d love to know, what are your favorite zinnia varieties?
*inspired by Soule Mama’s beautiful Friday reflections
In the fall after a few hard frosts, typically early November for us, we start the exhausting process of digging and storing tubers. I know some growers who are able to employ the help of machinery for this process but around here, the whole thing is done by hand, one clump at a time. No one hates it more than me.
Over the years we have tried numerous methods for storing tubers once they are dug but by the end of the season, moral is low, we’re exhausted and everyone just wants to be done for the year so we’ve begun to kind of cheat. Now this is going to HORRIFY the pro’s out there, but here’s exactly what we do.
The soil seems to keep them hydrated enough to avoid shriveling and then in mid-late March when we’ve regained our love for farming once again, we pull out all the crates, hose off the clumps and start the tedious task of dividing.
Another method which we used that had very a good success rate was the Saran Wrap method. After the tuber clumps were lifted and washed, we dipped them in a 5% bleach solution and then laid them out to dry in our cool garage for a day of two. Once the clumps were dry, they were carefully divided and then each tuber was separately wrapped in a piece of Saran Wrap.
The wrapped tubers were tucked into plastic bulb crates, stored in the 40-50* room in our basement for the winter and we consistently saw a 95% survivability rate. The few tubers that did rot were safely kept away from the others by the plastic barrier.
This fall with too many to fit in the basement and no energy to tackle dividing them all up we decided to try a little experiment and left about 1,000 clumps in the field to overwinter. We live in a pretty mild climate (zone 6B) and with a thick layer of mulch (leaves and straw) we felt that it might be enough protection to carry them through if things didn’t get too cold.
Once the mulch was down we covered the entire patch in weed barrier to help keep them extra insulated and dry. Only time will tell if they made it through but fingers crossed since our winter was a relatively warm one.
Now, to divide tuber clumps you’ll need some sharp pruners, an exacto knife (we prefer the pen type with the thin angels blade) and a heavy duty pair of loppers. Begin by splitting the clump in half with either loppers or sharp pruners which will leave you with smaller, more workable pieces.
The halved clumps are then divided again into individual tubers from there. In order to have a viable tuber, it is essential that the eye and neck are left unharmed. If you want a great little dividing primer plus how to spot the eyes, check out the Snohomish County Dahlia Society page.
We like to leave two or three tubers connected together (if we have plenty of that variety) because it seems to help the main neck stay more sturdy. Does that make sense? You can see it pictured above.
With a little practice and patience, it gets pretty easy to spot eyes and separate tubers with accuracy and speed.
Getting your mother stock of dahlias started is often a bit of a financial investment, but once you have a base, each tuber will produce 5-20 more tubers by seasons end. You’ll be swimming in a sea of both flowers and excess tubers in no time!
Favorite sources (USA):
Sunny Meadow Flower Farm is offering some of their extra dahlias for sale this year including the coveted Cafe au Lait’s. This variety is hard to find so you better snag them while you’ve got the chance! Owner’s Gretel and Steve suffered a major loss last month when their newly finished greenhouse was destroyed by a snow storm. The sale of their tubers will go towards helping cover the cost of replacing the greenhouse. You can see more of the story over at their Indiegogo campaign HERE.
K Connell Dahlias is a great source for very reasonably priced tubers and they have a list of 66 varieties that are available in bulk (5/$10). A total steal! Connell’s has wonderful customer service, a nice variety selection and top quality tubers.
Accent Dahlias here in WA is one of my most treasured sources for hard to find varieties as well as tried and true favorites. Owner Ken Greenway is a wealth of knowledge who generously shares information with anyone asking! I have visited the display garden at Accent nearly every year since discovering it and love working with Ken. His, selection, tubers and service are outstanding! Currently they do not offer wholesale pricing.
Swan Island Dahlias in Canby OR offers one of the largest variety selections in the country. In addition to their retail shop, they offer wholesale pricing for growers who spend over $250 on their initial order; reoccurring orders within the same season only require a $100 min to qualify. Varieties must be purchased in lots of 10 for the discount and variety selection is limited.
If you have sources in Canada the UK, AU or NZ that you love, please leave their info in the comments section below!
I get asked all of the time what my favorite flower is and answering always feels a little like singling out a favorite child. In truth there really are no favorites, just preferences at a given moment depending on circumstances like the mood that day, what’s peaking in the garden, the weather and so on.
During the long, hot summer stretches I often dream about them, counting to fives, rubber banding their stems and placing them into water. Over and over again. Many late summer days are spent entirely in the dahlia field, from sun up to sunset harvesting and bunching, driving truckloads back and forth to the cooler. On dahlia harvest days we are all ready for the change of pace and welcome the monotonous, beautiful, steady task that it is.
We’ve tried numerous approaches and techniques to growing our dahlia crops over the years. Here I’ll share what all of that trial and error has boiled down to but please keep in mind, this is what works for us, in our climate and based on our own personal production goals. We have severely limited space so must grow our plants closer together than we would if there were huge rolling fields at our disposal.
We also grow our flowers organically, so I won’t be recommending a bunch of chemicals but instead what we do to preventively combat insects and disease. Some of it may sound a bit “woo-woo” but the approach has worked very well for us and I think it might for you too. If you have any tips or tricks that you’d like to share (organic or not) feel free to leave them in the comments section below. It’s always nice to hear what others are doing all around the world.
90% of our dahlias are grown out in the open field. Our little plot is situated on top of a sandbar, literally. If you dig down just a foot, you’ll find silver beach sand, so we rely heavily on large doses of compost for fertility and thick mulches to help retain moisture through the drier parts of the season. We generally begin field planting about two weeks after our last frost date (4/25) with the process normally consuming the early part of May. Prior to planting all beds are amended with 3-4” of compost, rock phosphate, a little lime and a general organic fertilizer.
This mix is tilled in and then tubers are placed roughly a foot apart down the row, with two rows per three foot wide bed. Dahlias need a lot of water throughout the season. We run three lines of drip irrigation per row and then mulch over the top of it with a thick layer of leaves or dry grass clippings to help keep the water from evaporating. While this process is very labor intensive, once the tubers are in, dripped and mulched we do very little to them for the remainder of the season.
When sprouts begin to emerge, we go through and pull back the mulch from around the crowns. Once the plants reach rough 12″ we give them a hard pinch (snip out 3-4″ of the growing center) which encourages low basal branching, increased stem count and overall stem length.
We then start applying a bi- weekly doses of compost tea (with added kelp, rock powders and fish emulsion) to promote strong growth and help combat disease. T-posts are placed every ten feet on the outside of the beds and a double layer of bailing twine is attached to corral the bulky plants. In past seasons we’ve used tenax flower netting to help support plants but getting it off at the end of the year was a nightmare so we switched over to the twine.
For big fluffy, fragile blooms like those of the dinner-plate group, we’ve recently changed over to growing them indoors. This tiny tweak has made a world of difference in both productivity and stem length, but flower quality has also shot through the roof! Tender monsters like the Cafe au Lait’s really benefit from being out of the weather. Our plants reached over 7ft. inside the hoop-house and that was with twice a week harvesting!
Next season the plan is to use a sturdier support system (wire mesh instead of the twine) to help corral their incredible bulk. Pinching low is essential for useable flower stems on these beasts! Trying to get a dahlia with a stem as thick as a broom handle into a bridal bouquet or centerpieces is a nightmare. Our hoop-houses are unheated but with the extra insulation we were able to tuck tubers into the beds by mid March.
Insect pressure varies from season to season. Some years aphids come in abundance, other years like last thrips are a big issue and earwigs, those little bastards are always lurking, ready to chomp the perfect blooms. We’ve found that the healthier the plants, the less insect pressure we experience, so we do a lot of work to keep plants healthy and well watered throughout the season. Just like the human body, the stronger our immune systems, the easier time we have fighting off intruders.
In really extreme cases of aphids we have resorted to a few application of insecticidal soap to knock back the population. Safer brand makes and OMRI approved concentrate that you can find at most garden and hardware stores. Because of on going western flower thrip pressure, we’ve stopped growing white dahlias in the field and instead have better luck with them indoors. I’ve read about a few OMRI approved options that we might test out in the near future but so far, nothing has been very effective.
In the hoop house especially, earwigs wreak havoc and we’re still trying to find a good solution. Someone suggested last year that laying out pieces of plastic irrigation pipe with one end taped off would lure them in. Then in the morning you sweep through the patch and empty the pipes into a bucket of soapy water. We got so busy last season that I didn’t give it a proper go but am determined to try it again. There’s nothing more heartbreaking than seeing dozens of Cafe au Lait blooms chomped into bits!
While dahlias aren’t a terribly long lasting cut flower, their brilliant colorful blooms make up for their fleeting existence. The trick for longest vase life is keeping them well hydrated from harvest to the end consumer and to cut them from the plant at the proper stage. We harvest our patch every three days, rain or shine and never leave a single ripe flower on the plant. This protocol ensures that every harvest day is efficient because we aren’t having to examine individual blooms for signs of imperfection.
In the past, when we’ve skipped a harvest or delayed it by a few days, we end up spending twice the amount of time in the patch sorting and grading flowers. What a nightmare! The three day rule has changed everything and now we can comb the patch, almost without looking because every flower is at its prime and in perfect condition.
We cut straight into cool water, no preservative and the flowers are quickly shuttled into our 38-40* cooler for at least 12-24hrs. before heading out to customers. This approach gives a solid week of vase life and we’re consistently told by our buyers that our dahlias last longer than any others they’ve tried.
When I asked our friends Tony and Denise from Bare Mountain Flowers in Oregon what they do for the best vase life they shared, “We harvest early in the day before noon and put all the stems in a solution using Chrysal Gerbera Chlorine tablets. We use 1 tablet per gallon water that has OVB hydrating solution. The flowers are left in the hydrating solution for 2 hours in our cooler and then transferred to a fresh container with one more chlorine tablet per gallon of fresh water. We use no flower food as we are typically moving the flowers to market within 24 hours of harvest. Once in the vase we do recommend use of a basic flower food.”
Bob Wollam from Wollam Gardens in Virginia also chimed in with his secret recipe,”We cut our Dahlias into hot/warm water in the field and then again into hot water with a Chlorine pill and Chrysal #2 in the packing shed. We then try to hold them for 12 hours in the cooler at 38 degrees before taking to market.”
Tuesday we’ll dive into digging, storage and dividing techniques plus my favorite sources for tubers here in the states! If you have sources in Canada the UK, AU or NZ you love, leave their info in the comments below and I’ll happily add them to the list.
It’s that time of year again. Time to take all of those winter daydreams and turn them into some sort of clear and easy to follow plan. If you’re struggling with this tricky feat, just know you’re not alone. I’m in the exact same boat!
So, as a little break from the mind dumbing task of tweaking spreadsheets, planting plans and field maps I thought I’d share my favorite 16 dahlias. These photos serve as a little reminder that spring really is just right around the corner.
Next week we’ll dive into to the best sources for tubers, how to build up your stock plants, plus a million photos and all of the nitty gritty growing specifics you’ll need to succeed with these amazing blooms.
Be sure to leave any specific questions below and I’ll make sure to cover them in the upcoming posts.