Cut Flowers to Direct Sow NOW!
Last week was our Average Last Spring Frost Date on our farm - May 15.
On our farm, our last harsh “killing frost” ❄️usually occurs sometime between May 1 and May 31. On May 15, we have a 50% chance of still experiencing frost. It’s a bit of a gamble sometimes planting on May 15, but it works about half of the time!
We use the May 15 date as our signal to begin direct sowing our heat-loving, summer-blooming Annual cut flowers, such as:
Our custom Zinnia mixes for instant, easy Zinnia bouquets.
Succession Planting Annual Cut Flowers for Continuous Blooms
Most people sow their seeds around their Average Last Frost Date… and then think they are done planting for the season.
And this is okay if you don’t mind having a flush of blooms in mid-summer.
But if you want blooms all summer long, I highly encourage you to “Succession Plant” (you can read a comprehensive, in-depth report on how we Succession Plant in THIS BLOG POST).
Succession Planting is a planting method that involves staggering the seed sowing dates. Instead of planting everything all at once (which results in a “feast or famine” situation 😞), the planting season is lengthened… which results in a lengthened harvest season.
As a general rule, I recommend sowing heat-loving, summer-blooming Annuals a MINIMUM of 2-3 times, about 2-3 weeks apart.
Check out the graph below. As you can see, blooming tends to peak and then decline quickly.
By planting 4 successions of Zinnias, instead of just 1, we can ensure we have top-quality blooms to harvest for months, instead of just a few weeks.
How Many Successions Can You Sow?
The number of successions you can sow depends on two factors:
How many months of “frost-free” growing time are available where you live?
How many days does it take for the plant to reach maturity and bloom (Days to Maturity)?
On our farm, we have about 5 months of “frost-free” growing - May 15 through Oct 15. That’s roughly 150 days to grow heat-loving, summer-blooming Annual flowers (it’s a little depressing to calculate that only 40% of our days in Michigan don’t have snow or freezing weather! 🥶).
Many cut flower varieties take about 65-100 days to bloom.
To determine how many successions I can plant, I count BACKWARD from my Average First Fall Frost Date (October 15).
Ex. Zinnias take 65-90 days from germination to bloom. I can plant them anytime from May 15 through about June 30. If I plant them later than June 30, it’s likely they will NOT mature/bloom before frost arrives on Oct 15.
NOTE: Plants grow/mature FASTER when the weather is warm and when day length is longest around the Summer Solstice on June 20. They grow SLOWER when the weather is cool and as days shorten heading into the Autumn Equinox on Sept 22. Take this into consideration when sowing seeds!
List of Cut Flowers to Direct Sow RIGHT NOW!
Here’s a list of great candidates for Direct Sowing AFTER your Average Last Spring Frost Date:
These are heat-loving flowers, so I recommend waiting until your soil is warm before direct sowing.
There’s no advantage to sowing them earlier when the soil is cold. In fact, trying to sow them too early could delay or even prevent germination!
These seeds require consistent temperatures of 70°F or warmer to germinate properly.
Even though May 15 is technically “safe” for sowing these seeds most years, I find the seeds I sow in June (when it’s warmer and the days are longer) grow much FASTER and more vigorously than the seeds sown on my Average Last Spring Frost Date.
The Zinnias in the photo below 👇were direct sown on June 30… and they started blooming by August 15! Because they were planted around the Summer Solstice and experienced peak light levels, they only took about 45 days to mature. It was a great discovery and taught me that I can plant heat-loving, summer-blooming Annuals much later in the season than I expected!
These plants bloomed like crazy until they were killed by frost on October 17.
Featured flowers: “Rainbow Mix” Zinnias, “Salmon Pastel” Globe Amaranth, “Fercita” Amaranth
So what are you waiting for?
Now’s the time to direct sow your heat-loving, summer-blooming Annuals. And don’t forget to Succession Plant them so you can experience beautiful blooms for MONTHS, instead of just weeks!
