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.
Do zinnias bloom again after being deadheaded?
One of the most crucial tasks in learning how to cultivate zinnias is to deadhead the blooms in order to keep your plants in bloom. By extending the blooming period of the plant, deadheading zinnias encourages the flowers to continue to bloom.
Cutting back the Zinnia flower heads after the blooms start to fade can encourage fresh growth. Because of their incredible hardiness, zinnias can be deadheaded without causing any damage to the plant.
Decide how far back you want to trim the stem to deadhead zinnias. Then, make a precise cut immediately above a row of leaves using a pair of sharp garden scissors. The plant will be encouraged to grow new stems and blossoms where you cut if you do this.
Zinnias bloom all summer long, right?
Since zinnias are annuals, their growing season is limited to only one. However, they make up for their short lifespan with blossoms.
All summer long, zinnias generate a ton of blossoms. The blooms give a splash of color to any garden since they are vibrant and happy. Additionally, the blooms are beneficial to the ecosystem since they draw pollinators like bees and butterflies.
Zinnia planting should be reduced.
Zinnias require regular trimming to thrive and to encourage growth. Although trimming zinnias isn’t difficult, it is crucial to know exactly how to do it in order to avoid harming the plant. The most important thing is to avoid heavily pruning the plant. This will only have a detrimental effect on how your zinnias grow.
If you want a bunch of zinnias with brightly colored blooms, deadheading is essential. To induce the formation of new flowers, the old blossoms are chopped off in this manner. The zinnia plant will grow lower to the ground if you deadhead it low on the stem; the opposite is true if you deadhead it higher up the stem. Since zinnias are so hardy, any option works quite well.
Find flowers that are brown or withering to know when to deadhead a zinnia. This is how you can tell when it’s appropriate to cut them off so the other blooms may shine. Cut off each blossom one at a time using hand pruning shears, being sure to leave plenty of the stalk. It’s acceptable if you remove some foliage as well.
When should zinnias be cut?
I was apprehensive about cutting back my tiny Zinnia plants. Everyone advised cutting them back to help them branch out and produce more flowers, and after doing a lot of research and watching several videos on YouTube, I decided to follow their advice. I shuddered and removed them all. Let me tell you, cultivating zinnias was the best choice I ever made! They multiplied like weeds! I have enormous, overgrown plants that have simply continued to bloom all summer!
Zinnia plant pruning is quite simple. Simply wait until they are between 10 and 12 inches tall; you want to ensure that they have a few sets of leaves. You should remove the plant tops when they get to this stage. With a good pair of pruners, I removed the top two sets of leaves by about 4 inches. (See the image above) It’s that simple to prune zinnias!
Where should zinnias be pinched?
An armful of zinnias are the epitome of the summer. These cheerful blossoms, which come in a vibrant spectrum of colors, are a must-grow for any flower enthusiast.
Since they are among the simplest cut flowers to raise, they make an excellent first crop for new growers and are a consistent, prolific performer for the majority of flower farms and gardeners.
Since the beginning, we’ve grown zinnias, and each year, I fall more and more in love with them.
Because they dislike the cold, zinnias prefer to be planted once it has warmed up a little. However, in chilly Washington, we start our plants in 72-cell trays in the greenhouse 4 to 6 weeks before our last spring frost. Many gardeners in warmer regions of the world are successful at direct seeding their zinnias out into the field.
Around the middle of May, after the weather has sufficiently warmed up and any threat of frost has passed, plants are tucked into the field. On our farm, we work to give each blossom the greatest possible start. Find out more about preparing the soil here.
After preparing the planting beds, we install four drip irrigation lines that are spaced about a foot (30.5 cm) apart, and we then cover the beds with a layer of pre-burned landscape cloth to keep weeds at bay. With five rows per bed, plants are spaced 9 inches (23 cm) apart.
Plants can grow enormously large and require some sort of support if given suitable soil and a consistent supply of water. We employ a layer of horizontally stretched Hortonova netting that is 12 inches (30.5 cm) above the surface. Metal hoops that we bent using our Johnny’s Quick Hoops Bender are used to hold the netting in place. Any stake, whether made of wood or metal, will do. As the plants develop, they push through the netting grid and receive the support they require.
Because they prefer the heat, zinnias must be grown in full sunlight. I always grow them in cloth for the extra heat in addition to choose a sunny location.
Since they are cultivated in such rich soil, there hasn’t been a problem with disease, which I was concerned about when we first started planting zinnias this close together. Every two to three weeks, we succession sow zinnias to provide a constant supply of these lovely blossoms throughout the summer.
Pinching your zinnias when they are young is the key to getting the longest stems from them. Here is how to accomplish it: Use sharp pruners to remove the top 3 to 4 inches (8 to 10 cm) of the plant when it is between 8 and 12 inches (20 and 30 cm) tall, right above a set of leaves. This instructs the plant to grow more stems above the point of the cut, increasing both bloom production and stem length. The image up top shows pinching with a different kind of plant.
Deadhead any spent blooms if you don’t routinely pick your zinnias in order to direct the plant’s energy toward growing new blossoms rather than setting seed.
Zinnias must be selected when they are completely ripe in order to stay fresh in the vase. Use the to determine if a zinnia is ready to be harvested “Waggling test Just gently shake the stem while holding it approximately 8 inches (20 cm) down from the blossom head. The stem is not ready to be cut if it droops or bends. It is time to harvest if the stem is rigid and continues to stand upright.
Zinnias are regarded as a “Adding a few drops of bleach to their water will help clean up soiled flowers. Given that the flowers are quite sensitive to cold, do not place them in the cooler.
There are an astonishing variety of zinnias available in every imaginable size, color, and shape. Whatever your requirements, there is undoubtedly a zinnia for you.
Consider how many options there are if you’re looking for flowers in the peach-salmon color spectrum, for instance.
Giant Salmon Rose, Cinderella Peach, and Queen Lime Orange are in the top row, from left to right.
When the season is over, what should you do with zinnias?
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.