"They'll Take Over" Self-Sowing Flowers

In my conversations about some plants with other farmers and growers this summer, I often heard, "but be careful, they'll take over!" 

Their words of warning were music to my ears. Because our farm is new, and there are still many gaps in the fields and perennial beds to fill in, I dream of plants that will self-sow or spread easily and "take over." In those early rainy weeks last spring there were times when I thought - "I will never know what it means to dead head on this farm. I am going to have to harvest every single damn flower at just the right time." Of course that was not true, and my plants and Mother Nature came through, as always. 

Anyhow- I compiled my notes from those conversations into a list of flowers that I hope will come to sustain themselves relatively well, even here in zone 3/4. I'm collecting their seeds and sowing many of them right back into some perennial beds. As always, I try not to "go all-in" with one method. Some of their seeds will be saved to be spring sown. 

  • Amaranth: This annual is a workhorse, it's seeds contain a lot of protein (1 cup of cooked amaranth grain = 20% of your daily value), and it makes thousands of seeds per stem. Amaranth also has more folic acid than wheat. A few shakes at the end of the season into prepared, weed-free beds will lead to many more of these highly desirable plants the next year. In colder climates, consider sheltering beds from strong winter wind and extreme temps. Amaranth took center stage at the "moody shoot." It is the drape-y maroon and salmon foliage was hanging down over the tables and pouring out of centerpieces.
  • Sweet Annie: "It's a weed," was one of the most common things I heard from other growers this summer. But Sweet Annie's scent is intoxicating and it dries beautifully for wreaths. I am hoping to start a permanent patch of it from my own saved seeds.
  • Nigella: I mentioned a few times to friends that I had trouble getting many successful Nigella plants from seed this year, and just as many times, I heard back, "They self-sow like crazy!" I collected their seeds and spread them in a perennial bed for next year, so we'll see what happens. (Tip- you can also save seeds from the pods you buy from a wholesaler, just make sure that they dry out fully and turn black before you plant them. Discard any seeds that remain small and/or green.)
Nigella 'Delft Blue'

Nigella 'Delft Blue'

  • Frosted Explosion Grass: This stuff spreads like crazy. I found little patches of it popping up all around the farm in the second half of the season. It is valuable as a filler green, and several of my customers came to ask for it by name. Buy one seed packet one year, and you should never have to buy it again if you save seeds. 
Frosted Explosion Grass

Frosted Explosion Grass

  • Mint: There are all kinds of methods listed online for "containing" mint. But I want a huge patch of it! My mint garden is bordered on one side by lawn that we mow and on the other by tall hydrangea plants. Hopefully it grow really big without becoming a pest. This year, I was able to tuck mint stems into small personal flower arrangements (like floral crowns) for scent. I'm hoping to have longer stems for design work next year. 
  • Cleome: This self-sowing annual is great for cut flower work. The stems are long and the spidery flowers are large- so they pack a punch in arrangements. Cleome bloom from early summer to frost on stems that keep growing taller and taller. They will be new to my gardens next season. They come in pinks, purples, and whites. I have 300 seeds to try for next season. Half will go into a prepped perennial bed this week. The others will be saved for spring sowing. The "Queen" series is reportedly the best at self-sowing.
  • Chinese Lantern Plant: I started our first Chinese Lanterns from seed last spring and planted the seedlings out in a perennial bed, only to see them decimated by some kind of bug early in the season. I applied several rounds of my own homemade compost tea and two rounds of Safer Organic 3 in 1. I don't know if the applications made much difference in the outcome, but the plants did come back! They are sporting the first little orange lanterns right now. My first year plants are very small, but they should grow to about 2 feet tall and supply hundreds of beautiful stalks of orange lantern blossoms in late autumns to come. Some people consider this plant to be invasive. Mine have dedicated space in a row, where I can mow on either side. Customers love them fresh or dried. 

What are your favorite self-sowing or easily spreading flowers? Please share your thoughts in the comments and help this list grow!