How to Grow and Harvest Zinnias
We were incredibly surprised at the success of our many zinnia plants this summer. When we first transplanted them this spring, I was so worried that they wouldn't make it as many of them wilted and yellowed at the shock. It was a first for me! Usually zinnias had done well before that. We learned soon after that zinnias are not huge fans of transplanting, though many seed packages recommend that they are. Direct seeding is best if possible! Thankfully they all bounced back and have been blooming beautifully for the past month or so.
Growing zinnias is fairly easy and makes it a great choice for a beginning grower or young farm (we belong to both of those categories!). They are a "cut-and-come-again" flower which means that you can continue to cut them throughout the season and get the most beautiful blooms all the way through fall if the weather cooperates. You want to keep cutting a flower like this to get the most flowers out of your plant - it can be really hard to convince yourself to cut all of the blooms off, especially if you are growing for pleasure, but it is actually great for the plant!
I dress beds with a healthy layer of worm castings and straw mulch before planting. Zinnias are started 4 to 6 weeks before our last spring frost, though where we live in zone 5b I can direct sow seeds on and around the last frost date through April and May. By sowing that early, we get blooms by the first week of June! If you are growing on a small scale, try using the peat pots for transplanting so that you do not disturb the roots.
Normally I would water these plants with a drip line, but we decided the vegetables were more important and have been watering these with a sprinkler. I don't recommend using a sprinkler if you don't have to! It does not direct watering at the roots where it is most important and can waste most of what you are using. Next year we will add landscape fabric to help with weed control. This year I spaced plants with a 9x9 inch plant-by-row bed.
You can fertilize zinnias every month or so, though I hardly ever do this. They seem to do just fine on their own! Once the plants are around 18-20" I go through an pinch out the center bloom. This is hard to do as it feels like waste, but it will help encourage the plant to branch out from the bottom and grow longer stems with larger flower heads. We are so impressed by how many more flowers we have gotten with foot long stems, sometimes longer, by pinching!
When it comes time to harvest your first zinnias, look for those that have just opened or are beginning to show their first color. You'll want to locate the "end" of the stem you want to cut. This is where it meets a Y in between two new blooms growing. Cut at an angle in this place, which will encourage those two blooms on either side of the stalk to grow and bloom. Remove the leaves away from the bed and stick the stems in water immediately after cutting. We find it's best to harvest flowers in the evenings.
When you bring the blooms inside, you can feed them with a simple floral preservative (I use FloraLife), and they should stay beautiful for about 7-10 days, and sometimes up to 14 days depending on how early you cut them! Be sure to change the water daily, at room temperature, and remove any stems that are looking pitiful.
If you are looking to grow and sell zinnias, they are a perfect staple flower to have as they are so prolific. People love zinnias and sunflowers! They are also just perfect for the home garden as you will have a fresh bouquet at least weekly if not daily. We tend to find that if we harvest zinnias in evening, they are already filled with new blooms the next day! It's such a wonderful surprise to have.
Do you grow zinnias? What is your favorite color or variety?