Growing Delphiniums In New England
New England is a beautiful place with mountains and rolling hills, lovely beaches, and the best fall foliage that people come all over the country to see. Weather can change in an instant with downright brutal winters and summers that can be hot and humid. The saying here is if you don’t like the weather now just wait a few minutes. So what does it take to grow delphiniums, a flower of such sheer magnificence other flowers pale in comparison? Honestly, in New England not much.
America is a vast place with many varied climates, so what may work in one place may not work in another. New England lies in USDA growing zones 3-7 and has what’s called a humid continental climate stretching 500 miles from Maine down to Connecticut. Simply put we have long cold winters and moderately warm summers. I will say if you're ever visiting don’t come from the last week of July through the first week of August; typically that’s when we have a week or two where it's hot and humid before tapering off.
I’ve been told delphiniums were notoriously difficult to grow. As luck would have it a small magic fountain delphinium grabbed my attention many years ago, inspiring me to purchase it. In doing so I learned delphiniums were not difficult to grow. Personally I believe the American idea that delphiniums are difficult to grow is Americans’ lack of familiarity with delphiniums and the fact the pacific giant strain is labeled as a perennial. If you're not familiar with the pacific giant strain they were never bred to be perennial and there is nothing wrong with that just know they most likely won’t come up the following year. Trying them myself I have never had a pacific giant regrow the following year.
How do I grow delphiniums?
First and foremost, I prepare the garden bed using a mixture of leaf mold and cow manure, or a mixture of topsoil, leaf mold and cow manure depending on the condition of the soil; till it all in then put another inch or two on top. Subsequent years are much easier adding just an inch or two of compost on top, preferably in the fall/winter. Compost with this mixture can be found at quite a few farms around New England.
Now comes the fun part planting seeds. I plant delphinium seed from the beginning to the middle of January. I use a single cell tray with one cell that is cut out so that I can see the water level. Fill it with compost made of, you guessed it leaf mold and cow manure. Then all I do is poke a small hole with my finger, drop in a seed, and cover the seed up. If you have a habit of forgetting where you left off, like I do, poke a hole in every cell before planting the seed and cover the seed up as you go.
The reason for using a single cell tray is that young delphinium’s roots can get quite long. Using it saves me time when it comes time to pot the plants up and it lessens the chance of me damaging the roots.
Planting for me occurs typically around the middle of March to April where I am located. You can also look up your average last frost date; this can vary from year to year. A more reliable indicator for planting out your delphiniums is when the forsythias come into bloom. For spacing, I plant 2 ½ feet between delphiniums in my garden beds or dedicated delphinium bed. However, in a delphinium's first year when I’m seeing which ones I want to keep, I plant a foot between each plant.
If you're looking at getting cuttings from delphiniums you already have; start looking for them around the middle of February onwards.
June through July the delphiniums come into bloom although I have had the odd delphinium bloom mid May. It’s such a beautiful sight seeing groups of delphiniums in bloom and one I look forward to seeing every year. My daughters enjoy taking a stroll through the delphiniums with flowers that tower over them when they are in bloom pointing out which ones they like. After the summer bloom, I cut the flower stalks to the ground and typically end up with a second flowering starting in October and ending around the end of November.
Then I start all over again.
Growing delphiniums has been an interesting journey for me. In the beginning it was a very steep learning curve bringing with it joy, despair and everything in between. Today I grow mainly elatum delphiniums which bring me much joy. When I came back from deployment one of the first things I did was plant delphinium seeds and look at my delphiniums.
I have observed, and shared in the New England gardener’s thirst for knowledge about growing delphiniums, and believe it will lead to a promising future for this special flower in America.
