Dahlia Planting 6/3/22

Dahlia Planting 6/3/22

Posted by Mandy + Steve O'Shea on


  We’re back out in the fields, sweat pouring off us, making beds, pulling irrigation, organizing, laying out, digging in, and covering up our dahlias.  We’ve made surprisingly good progress in this heat.  Our team is good and getting better with each passing season.  The umpff we are losing with age, is offset by the wisdom gained from years of iteration.  Less vivacious, but more efficient. Cramping, tired, and sunburnt, we are excited to have thousands of dahlias successfully planted in raised beds.  When all is said and done, we’ll have about 8,000 in the ground.  Definitely our largest dahlia planting to date.  

  We’ve spent years isolating and multiplying the varieties that we prefer.  Those that are beautiful, productive, and strong in this hot climate, that also give the longest vase life possible.

  We’re finally happy with all the varieties we grow.  We’re even breeding our own new varieties that fill niche colors and shapes that we could not fill with pre-existing varieties on the market.

  There’s so much to look forward to in the coming months.  The waning of the intense heat will be coupled by the onset of fields full of what are arguably some of the most beautiful flowers in the world.  The shoulder seasons are always the most beautiful out here.

  Folks often wonder why we plant dahlias so late, since conventional wisdom recommends an early spring planting or even an overwintering approach.  We’ve tried every configuration and tactic possible with extreme tenacity and most approaches resulted in overwhelming loss and annual heartache.  Our discovery of an alternate approach was what ultimately made us the only substantial local dahlia growers at farmers markets for years.  I probably shouldn’t be sharing trade secrets, but here’s the skinny…

   In this hot climate, dahlias planted in early spring will pop up and look fantastic in late spring and early summer.  You think you are an amazing farmer.  You somehow have dahlias and peonies blooming at the same time!  But come mid to late summer, they are huge, unruly, heat stressed, and overwhelmed by pests.  Japanese beetles decimate them and whatever is left become a breeding ground for Western Flower Thrips.  Those thrip populations become so humongous that there is literally nothing you can do to stop them from devastating the plants and flowers and when Fall harvest time comes around…your plants are so sick and your flowers are so filled with thrips that you’ll be lucky to get one “good” flower out of ten.  Spray them with organic pesticides all you want, but you won’t put a dent in those thrips and even your good flowers won’t last long.

  We literally tried every organic approach on the market.  Everything.  Results were always the same.

  Instead of giving up, we tried a couple of new approaches.  Mandy suggested we buck convention and plant late.  This would prevent the plants from being so heat stressed for so long.  Now, we get them in the ground just late enough to avoid a lot of the heat stress, but just early enough to have them fully mature enough to produce bountiful flowers in September.  It's a small window, but now and for the next 2 weeks is pretty good timing. 

   This strategy also has them growing after Japanese beetle season, tarnished plant bug season, and prevents thrips from establishing themselves and producing generation after generation of exponential population growth.

  To diminish the thrip pressure even further, I started researching beneficial insects and the life cycle of the thrips.  I now use 3 layers of attack and prevention on the thrips.  A soil dwelling mite that feeds on the early life stage of thrips, a plant dwelling mite that feeds on a later stage of thrip life cycle that actually live in the plant tissue, and a generalized predator called Orius that aggressively prowls through the nooks and crannies of the flower petals to feed on the adult stage of the thrips.

  The late planting is a huge advantage, but the combination of that with the beneficial insects has been a game changer.  I don’t believe it would be necessary in a home garden to utilize beneficial insects purchased from a lab.  It’s incredibly expensive and is likely overkill in that setting.  A garden is filled with biodiversity and if grown organically is home to many predacious insects that will mitigate population explosion of most pests.  True problems come in monocultural settings. A farm plot with thousands of the same plant all right next to each other is the perfect environment for any pest with a quick reproductive cycle to explode in number and take over.  It’s possible that a conventional pesticide with systemic properties and long lasting killing power would address the thrip issue, but those same chemicals would end up in the soil, the run-off, in the creeks, rivers, lakes, and ultimately the ocean.  It would be in the insects and the birds and in the bodies of our employees.  It would be in the petals people sniff, put in their bath water, or decorate their cakes with.

  So instead of a scorched earth approach that may rid us of pests, but at the expense of our waterways, animal friends, and community members, we aim for loss reduction through dynamic equilibrium.  We don’t nuke the pests.  We introduce other insects that will reduce their populations and subsequent damage to a minimum.  To a tolerable level.  We can sustain some loss.  That is life.  

  Philosophically, we are internalizing costs instead of buying a cheap toxin and turning a blind eye to the downstream consequences.  The latter approach is what they call “Externalities” in Economics courses.  Better profit margins for the business, because all the damage is “externalized”.  Essentially it's paid for by outside entities.  By the community in the form of loss of wildlife or in the form of tax dollars to environmental cleanup, or loss of health and increased medical costs of employees and community members due to carcinogens in our food and drinking water, etc.  Sadly, so much of our industry is based on that.  But that’s a story for another day.  We are trying to do good on our little slice of land out here and just hope that it’s enough to influence others to consider the same.  It’s not always easy, but it is the right thing to do and it helps us sleep more easily at night.

   So do good, be well, foster harmony in your garden, your community, and in your heart and give your dahlias a fighting chance by planting in early June.

  P.s. if you are a farmer looking to find these mites…..the exact species you require will vary from location to location.  Some mites handle heat better than others.  Contact your beneficial insect supplier and discuss with an expert which ones will work best for you.  On the east coast, we use IPM labs in New York.  The west Coast has their own suppliers and since all these little buggers are shipped overnight, you’ll be best served finding the most proximal resource.

  Have a great weekend!