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.
Does deadheading zinnias increase blossom production?
It’s hot outside, so gardening in the summer calls for plants that are minimal care, drought and heat tolerant, and have vibrant colors.
The better, the brighter.
On each of the three criteria, zinnias were suitable. plus more. They’re among the best flowers that savvy gardeners may use in their gardens, in fact.
If there is a flower that is simpler to grow, please let us know. Since zinnias are annuals, their life cycle from seed to flower to seed is short. Simple garden preparation is all that is needed for zinnias’ arrow-like, pointy seeds to germinate. Simply place them in soil that is well-drained, in full sun, and in an area that receives a lot of summer heat, and you’ll soon see small seedlings and blooming flowers. No enduring can boast of that speed!
One gardening friend simply scatters seeds wherever she wants a few zinnias, waters those areas for a few days, and then lets the zinnias’ naturally easy-to-grow nature take its course.
“Candy Cane,” “Green Envy,” “Persian Carpet,” and “Pop Art.” When a variety has names like those, color is guaranteed. The ridiculous color palette of zinnias includes every vivid and pastel shade (aside from blue), as well as bi-, tri-, and crazy-quilt combinations made for cutting, luring pollinators, etc.
Many new zinnia series give options for height and width in addition to vibrant color.
- While Zinnia elegans tall varieties continue to be the preferred option for the back of the border, shorter series are now challenging the low ground once held by marigolds and petunias. The Thumbelina Series of dwarf zinnias reach their highest point at 6 to 8 inches, whereas the Magellan Series remain roughly knee high at 14 inches.
- The Crystal Series and other creeping or spreading Zinnia angustifolia are a revelation for the front of the border, raised beds, containers, and even ground coverings. The fact that its native to Mexico is even more drought tolerant than regular zinnias makes it the preferred choice for hot locations like sidewalk beds or that no-man’s-land next to the garage.
- With a height of about 8 to 12 inches, ZaharaTM zinnias are renowned for their resistance to powdery mildew and leaf spot (see below). In the entry beds of the Regenstein Fruit & Vegetable Garden, we paired Zahara Yellow, which is brief but sweet, with tiny sunflowers.
Zinnias are obviously meant for the vase because they have style and long, sturdy stems.
The words stars and daisies, dahlias and spiders, buttons and domes, and quill-leaf cactus are all used to describe zinnia blooms. Flowers come in different varieties: “singles,” which have their petals arranged in a row around an open center; semi-doubles; and doubles. Each one is fantastic in floral arrangements.
The best zinnias for cutting are, of course, the tall kinds; “Benary’s Giant” is renowned for its three-foot-tall, robust stems and huge flowers. Just above a bud joint, angle-cut zinnia stems. Zinnias often stay a long time in a vase; thus, remove all but the most obvious leaves off the stems before placing them in water.
Zinnias require little upkeep. Because they grow quickly, they shade out weeds. They don’t need mulching, and the only fertilizer they need is an occasional application of a well-balanced mix.
Deadheading encourages the growth of additional blooms. Lack of time to deadhead? When it comes to a big bed, the Zaharas indicated in the sidebard are a significant time saver.
The Profusion Series, a cross between Z. elegans and Z. angustifolia, is resistant to powdery mildew, which is the bane of zinnias, just like Zaharas.
Zinnias are accustomed to dry environments because they are indigenous to the grasslands of the southwestern United States, Mexico, and South America. However, wet summers, like the one we’ve had so far, can be damaging. And leaf spot and powdery mildew can result from that. Three recommendations for surviving inclement weather:
- Only water as necessary, and then only at the plant’s base. Wet leaves can encourage the growth of mildew, and water splashing can instantly spread fungus from the ground onto zinnia leaves.
- Taller, mildew-prone kinds can be hidden by foreground plants.
- As one horticultural put it, “Even when zinnias are coated in powdery mildew, they’re covered with flowers,” do both #1 and #2 and accept that zinnia leaves (but not flowers) are impacted by wet weather.
Zinnia seeds can be saved with ease. Simply let the blossoms to completely dry on the stalk, gather the seedheads, and delicately crush them in your fingers to release the harvest of seeds for the following year. In the same manner as other seeds, store in a cool, dry area. (And save some for our seed swap in February of next year in a labeled envelope!)
Last but not least, zinnias attract butterflies, so plant them every year. The plants with larger flowers serve as landing places for butterflies looking for nectar. (The same is true with hummingbirds.) To capture the most attention, try tall zinnias with scarlet or hot pink blossoms.
Living and gardening in Oak Park, Illinois, Karen Zaworski is a writer and photographer who specializes in gardens.
‘Benary’s Giant,’ one of the greatest for cut flowers, stands out in the English Oak Meadow with its 1,000 blooms.
Above: Double Zahara Fire (Zinnia marylandica), one of a group of plants resistant to powdery mildew, was cultivated in the Enabling Garden.
For your summer garden, the ZaharaTM Coral Rose Zinnia (Zinnia Marylandica) excels and requires little water.
Do zinnias have cut-and-come-again petals?
Cut and Come Again Zinnias, a popular term that delighted gardeners, was given to the “Pumila” combination of zinnias, which caused a sensation. Since they all grow so easily and bloom for such a long time, their performance is essentially the same. If you cut the wilting flowers, they will all “come again.”
So simple! Why zinnias are so popular: No plant can likely provide you with more color for less effort. This is due to the fact that zinnias are among the easiest plants to cultivate from seed (even young children can do it, and many do! ), that they bloom all season long until the first frost, and that they produce all colors but blue. Another flower that accomplishes all of that come to mind?
How to raise them Really, only good full sun is necessary, however some of the more modern hybrids will even bloom in partial shade. Given that they originate from hot, desert-like settings, they don’t require much water. Soil? Almost any type of soil will do, but if you have access to it, they prefer grittier, faster-draining soil.
For an early flowering, zinnia seeds are ideal for starting indoors. However, make sure to wait until the last of the frost has passed and the earth has warmed up a little before planting them. Since these plants are native to frost-free climates and dislike chilly soil, they are extremely susceptible to frost. You can wait until spring to plant them outside if you’d prefer. They are not at all demanding.
The Wildflower that has been adorned for a long time. The majority of the 20 species of Zinnia found in the wild are from Mexico, and they may all be found in the dry, rocky soils of North, Central, and South America. Since zinnias are one of our most heavily hybridized wildflowers and the rather “ragged” originals don’t resemble our garden beauties, you would be astounded if you saw the wild plants. That’s because hybridizers have been “working on” them for decades after discovering them early.
The Untamed Ones The species Zinnia elegans, a typical wild plant in Mexico, is the one that is hybridized the most. However, several of the other species have been the subject of research in recent years. The Zinnia adapts fast and willingly to practically whatever the hybridizers wish to do, much like the Dahlia (also from Mexico): larger, taller, or smaller blooms. colorful flower varieties. They appear to be able to do anything to Zinnias, no matter what it is.
Because of this, zinnias have been a mainstay among major color-makers in gardens since the time of your great-grandmother, and new varieties are being developed for our gardens virtually every year.
When will zinnias bloom again?
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.