How Zinnias Grow

One of the simplest flowers to plant, zinnias grow quickly and provide a lot of blooms. Additionally, they will continue to bloom right up until the first fall hard frost. Consider trying zinnia flowers this year to add a huge splash of color to your yard.

About Zinnias

Since zinnias are annuals, they will only produce blooms and seeds for one season before dying. The original plant will not reappear the following year. They are excellent for use as a cutting flower or as food for butterflies since they have vivid, solitary, daisy-like flowerheads on a single, tall stem.

Types of Zinnias

Zinnia elegans, the most widely grown zinnia species, has been developed to produce a large number of distinctive variants.

Single, semidouble, or double zinnia blooms are the three most common varieties. The number of petal rows and whether or not the flower’s center is visible serve to distinguish between these forms:

  • A single row of petals and the center are both visible on single-flowered zinnias.
  • Petal rows abound on double-flowered zinnias, and their centers are hidden.
  • Between the two are semidouble-flowered zinnias, which have several rows of petals but discernible cores.

In addition to these shapes, zinnia flowers also occur in “beehive,” “button,” and “cactus” forms. Additionally, the plants themselves come in various heights: taller types function best as a garden bed’s background, while shorter varieties are useful as a border. There is a zinnia for every garden, in fact!

In an annual or mixed border garden, plant zinnias. Smaller zinnias work well as window boxes, edging, or in other containers.

To have a lot of flowers all season long, choose a place that receives full sun (6 to 8 hours of sunlight every day). Additionally, later in the season, foliar diseases like powdery mildew can be avoided by planting in an area with sufficient air circulation.

Although zinnias can grow in a variety of soil types, they prefer organically rich, well-draining soil. The optimal pH range for soil is between 5.5 and 7.5. The blooms will grow more quickly if compost (humus) is added to the soil. Find out more about soil improvements and getting the soil ready for planting.

When to Plant Zinnias

  • Because they dislike being transplanted, it is advised that you start your zinnia plants from seed directly in the garden bed. If the correct circumstances are present, they will develop quite quickly from seed.
  • It should be noted that zinnias can be grown from seed inside if you like. Just make sure to transfer them gently and young.
  • Because zinnias are delicate to frost, wait to plant them until after the last frost in your area. See the frost dates in your area.
  • Zinnias can tolerate daily temperatures as low as 60F (16C), although a range of 7484F (2328C) is ideal.
  • To prolong the flowering time, sow a new crop of seeds every week or so for a few weeks.

How to Plant Zinnias

  • Depending on the kind, place plants 4 to 24 inches apart. (Many common kinds are planted 2 feet between rows and 6 inches apart within the row.) For information about each variety, consult the seed packet’s back.
  • Plant zinnia seeds no deeper than 1/4 inch.
  • The majority of zinnia cultivars will produce seedlings in just 4 to 7 days, but it may take up to two months or more for blooms to appear (depending on planting site and climate).
  • To promote air circulation, thin seedlings when they are three inches tall, spacing them 6 to 18 inches apart. As a result, powdery mildew is less likely to grow.
  • To promote development and blossoms, keep the soil’s moisture level moderate and apply a mild fertilizer.
  • Deadhead zinnias once they have finished blooming to facilitate the development of new blossoms.
  • Since zinnias are annuals, they will perish with the first fall hard cold. Let the final blooms of the season fully mature before dispersing their seeds if you want them to reseed.

Zinnias still not your thing? In your garden, try them out for the following six reasons:

  • With cultivars from the Dreamland Series, you can have a full-sized flower on a little plant. These zinnias are compact and dwarf, with stems that are 812 inches tall and totally double flowerheads that can be up to 4 inches across with a variety of colors.
  • The dwarf, spreading cultivars of the Thumbelina Series have weather-resistant, solitary or semi-double flowerheads in a variety of hues. Their stems can reach a length of 6 inches, and their petals are 1-1/4″ wide.
  • One of the largest and tallest of them all, the State Fair Series has huge, double flowerheads that measure 3 inches in diameter. Stems can reach a height of 30 inches.
  • Typically, it takes zinnias 60 to 70 days from seed to flower (though it depends on conditions and variety). They are fantastic in a bunch of flowers!
  • The tiny, narrow-leafed zinnias are great for hanging baskets and also make lovely dried flowers.
  • Zinnias are considered to represent memories of those who have passed away. Discover more about the significance of flowers here.
  • Zinnias may be harmed by bacterial wilt, powdery mildew, and bacterial and fungal spots. To prevent illness, keep leaves from getting too damp and correctly space your plants.
  • Problems can also be brought on by caterpillars, mealybugs, and spider mites. Spraying should be avoided unless there is a real infestation because some leaf damage is not a problem.
  • Thanks to their resistance to deer, zinnias may be able to prevent surrounding flowers from being eaten.

Zinnia plants grow in what ways?

Light: Full sun is ideal for zinnia growth and flowering. Even in warmer climates with afternoon shadow, they can flower there, but they may be more prone to disease and produce fewer flowers.

Soil: Organically rich, fertile soils with good drainage are ideal for growing zinnias. Because zinnia seedlings are susceptible to rotting in cool, damp soils, having well-drained soil is crucial.

Plant zinnia seeds in rows or clusters spaced a few inches apart. Once the plant has four leaves, thin to 8 to 18 inches apart, depending on the variety.

Planting: Plant zinnias in the spring, just about the time you plant tomatoes, when all threat of frost has passed. Growing zinnias from seeds straight in the garden is simple. Start seeds inside four to six weeks before to your last frost date for earlier flowering.

Do zinnias regrow after being cut?

The extreme heat and dry conditions have forced many growers to scramble to tend to and harvest their stressed fields and gardens, including here on our farm in the Skagit Valley and throughout much of the Western United States. While many flowers bloom profusely in this kind of weather, it is crucial to know the optimum times to harvest and ways to care for your fresh cut blooms immediately after they are cut if you want your flowers to last as long as possible—especially with the added stress of high temperatures. (This is referred to as “stage of harvest” and “post-harvest handling” in the language of flower farmers.)

Here are some of my favorite hints for avoiding heat waves and getting the longest vase life possible from 10 high summer flower varietals.

Zinnias: To ensure a long vase life, zinnias must be harvested at the proper time. Wait too long, and the blossoms will swiftly fade; harvest too soon, and the stalks will sag and droop. The “wiggle test” is a pretty easy way to determine whether your zinnias are ready for harvest. Simply take hold of the stalk a few inches below the flower and gently shake it. The stem will be delicate and flexible if it is young. When you wriggle the stem, it should stay rigid and straight if the plant is ready to be harvested. Cut time has come! To create a long, sturdy stem, deeply cut the plant. Don’t be hesitant to clip off lateral sprouts on the main stem you just plucked; remove the foliage as well. Because zinnias are “cut and come again” flowers, they will continue to grow all season long even after being severely pruned.

We cut zinnias and place them directly into clean, fresh water that has either been supplemented with a drop of chlorine or a CVBn pill. The little conditioning pills, which are frequently marketed for gerber daisies, are actually ideal for all of the “dirty flowers with hairy stems that easily gather dirt and bacteria that can muddy up the water.” The hottest time of the year is when zinnias blossom continuously, and they also enjoy heat throughout the post-harvest period. One of the few flowers we don’t treat in the cooler before delivery or design work is this one. Simply said, we keep them out of direct sunlight in a dark, shaded area of our studio. These few easy steps will give you gorgeous, long-lasting blossoms that last 7–10 days in a vase.

Note: In general, certified organic agriculture does not permit the use of commercial flower food. Using bleach or hot water and harvesting at the right stage are crucial if you have certification. To give your flowers the longest possible vase life even if you are not certified organic, CVBn tablets and other hydration and conditioning options are worth the extra money.

Basil: During the height of the summer, we nearly always add at least one or two stems of Cardinal, Oriental Breeze, Lemon, or Cinnamon basil in our mixed bouquets of flowers for grocery store clients. When the flower heads start to appear and the stems start to harden, I pick the basil. To keep them from wilting, I treat them with Quick Dip (a non-organic alternative) or boiling water (an organic alternative). As these plants wilt quickly, be cautious to harvest them in the cool of the morning or evening. Basil doesn’t like the cold, just like zinnias, so keep them out of the refrigerator to finish their conditioning. The vase is frequently where stems root, and they should last 7 to 10 days.

The fuzzy, aromatic leaves of scented geraniums are a must-have for bouquets, but if you don’t take a few simple precautions, they could wilt easily. In order to avoid the heat of the day, I always attempt to trim the scented geraniums first thing in the morning. I sliced them, placed them in cool water, and gave them 3–4 hours to rest and condition before arranging them. Dip the bottom 2-3 in boiling water for 5-7 seconds or dip the stems in Quick Dip if they are still wilting.

Another flower that is prone to wilting is the hydrangea. Perhaps more significant than the harvesting stage is how you hydrate the produce after it has been sliced. My secret is to cut them when they are still chilly, use Quick Dip quick hydration solution, or cut them into hot water for organic production. I am familiar with some flower growers who swear by dipping the just-cut stems in alum powder (found in the grocery store’s spice aisle), while others would soak the entire bloom in water before use to prevent wilting.

Cosmos: Cosmos generally don’t have a very long vase life, but if you cut them at the proper point, you can extend their beauty. Cosmos should be cut when just one petal is beginning to unfold, and once that happens, let the vase’s other buds and blossoms bloom.

Sunflowers: Harvesting the blooms just as the first few petals begin to lift off of the central disk and removing all but the top few leaves will give your sunflowers the longest vase life possible. This can be challenging for beginners since it still appears to be “closed” and not ready to pick, but if you cut them early, you can prevent bug damage and enjoy longer vase life. These people, who are referred to as “dirty flowers,” may benefit from some bleach in the water or from being cut into a pail of water that has been CVBn-treated.

Celosia: When harvesting crested celosias, also known as “cock’s comb,” wait until the crests are fully grown (or a bit sooner is good too), but before the plant begins to produce seeds. Before plucking celosias with feathers, let them stretch and become feathery. Make sure to remove around 3/4 of the leaves after cutting and submerge them in cool water.

Cerinthe: Harvest during the coldest part of the day, then immediately treat stems by putting the bottom 2-3 inches in boiling water for 7–10 seconds, followed by a cool water bath. After harvest, stems become extremely floppy, but once hydrated, Cerinthe can last up to a week in a vase.

Harvest rudbeckia when the flowers start to unfold. Black Eyed Susans are infamous for fast turning their water murky. By reducing this and extending their vase life, you can expect a vase life of 7 to 10 days by adding a few drops of bleach to the water.

If you have any more advice or methods for gathering high summer blossoms and extending their vase life, please let me know. Please share any more advice in the section below.

When do zinnias bloom in the year?

Zinnia flowers, one of the easiest annuals to grow, are a vibrant riot of color. From late April until the first frost in the fall, the exhibition runs. The joyful flowers, which bloom in almost every vivid hue imaginable, draw butterflies and hummingbirds. They are a fantastic option for novice flower producers because they produce flowers rapidly and consistently. You can’t go wrong when you take into account their low care needs and the range of sizes and shapes.

How long do zinnias need to grow before blooming?

Beautiful flowers like zinnias are ideal for novice gardeners! These annual flowers come in a wide range of hues and variations, adding a vibrant pop of color to your yard and making them ideal for bouquet-making. Zinnias require only plenty of sun, warmth, and well-drained soil to thrive and can be grown without much care from summer until the first hard frost in the fall. They don’t have any significant pest issues and can draw lovely butterflies to your garden.

Depending on your location, the growing strategy may change slightly. When the temperature starts to rise, zinnia seeds can be sown immediately into the garden in warmer climates. Here in New England, it takes longer for the temperature to rise, so if you can keep the soil between 70 and 80 degrees F, you can start the growing process about a month before the final frost is predicted. Since zinnias dislike being transferred, sow seeds in peat pots that can be placed straight in the garden. From seed to flower, zinnias normally require two months, though this might vary depending on the weather.

Here are some more hints for growing zinnias:

  • For your zinnias, choose an area that is sunny and bright.
  • Zinnia seeds require sunshine to sprout, so only cover them with 1/4 inch of dirt.
  • Keep the soil damp while the flowers grow.
  • Thin seedlings to 6-8 inches apart for small varieties and 1 foot apart for large varieties when they are 2-3 inches tall.
  • Avoid drowning the zinnias in water. Water intake of 1 inch per week is advised.
  • To encourage the zinnias to generate more blooms, remove any faded or dead flower flowers. Deadheading is the term for this.