Zinnias are one of my all-time favorite flowers for the cutting garden. Not only are they big, bright, and beautiful, but they also have a great vase life. With long, slender stems and their excellent production rate, it’s no wonder they are so popular. If you’re growing them, you’ll want to know how to make your cut zinnias last as long as possible.

A zinnia’s vase life is variable, depending on how you cut and care for it. The average vase life of these flowers is about 5-7 days. However, with proper care, you can make them last up to 10 days. I’ve even had them last for two weeks!

Along with their long vase life, other qualities make zinnias great cut flowers. They are fast growers, blooming in as few as 50-60 days after planting. You can directly sow them, so they require little effort to get them started. They also produce a ton of flowers per plant.

Naturally, with all of these remarkable qualities, this is a common selection for the cutting garden. If you handle them well, you’ll have beautiful bouquets throughout the summer, and often through the fall as well. If you want your cut zinnias to last, there are a few simple tricks to cutting and caring for them.

Cut at the Right Time

When I say to cut them at the right time, I’m talking about two distinct factors. That is, the right time for the plant, and the right time of day. First, let’s talk about the stage of development that is ideal for cutting if you want to make those cut zinnias last.

Some flowers in the cutting garden are good for cutting in the bud stage. Roses and peonies, for example, fall into this category. This is ideal for flowers that continue to open after you’ve cut them. Zinniason the other hand, do not continue to open after cutting, so this is a bad idea.

You want to wait until the flowers are fully open and the stem is stiff and strong. If you see a fully open bloom and are unsure about the stem, you can perform the ‘wiggle test.’

Gently shake the stem back and forth. If the stem, near the flower, remains stiff, it’s ready to cut. If, on the other hand, the flower wobbles around on a weak stem, leave it be.

Factors that contribute to strong stems include pinching the young plants to encourage strong branches. Adequate sunlight and watering are also factors. Direct sowing your seeds will cause them to be stronger in general and more firmly rooted.

The time of day that you do your harvesting is also important. Your zinnias will be at their strongest and freshest first thing in the morning. This is when they’re fully hydrated and haven’t been wilting in the hot sun all day.

It’s ideal to water your zinnias early in the morning, give them an hour to absorb the moisture, and then cut them. Aim to cut before 9 a.m. for the freshest, most hydrated flowers.

Prepare Your Vase Early

When I cut flowers from my cutting garden, I prefer to take a jar of water along. This way, I can place the stems directly in the water, immediately after cutting them. Prep your vase ahead of time, even if it only takes you ten minutes to do your cutting.

Zinnias like a bit of lukewarm water initially. Your stems will absorb cold water, but they will do so more slowly. By giving water at room temperature, or just slightly above, they will drink it quickly, keeping them well hydrated. Avoid using water that is too warm, as this can shock or damage them.

Fill a jar or vase with clean, lukewarm, or room temperature water. Add some flower food for an extra boost. As you cut your zinnias, place them directly in the jar or vase. Leave them in this liquid for a few hours to allow your stems to take in as much as possible. Then, give all your stems a fresh cut when arranging them and place them in fresh water with flower food.

Refresh Often

The next important step is to change out your water often. Every one to two days is ideal, but at least every three. This is an area where I, admittedly, fall short of my best. But if you want to make your cut zinnias last as long as possible, it’s important.

Old water is a breeding ground for bacteria. Once it gets in there, which it inevitably will, it will proliferate. That bacteria clogs up the ends of your stems, which reduces their ability to take in moisture. You’ll end up with slimy, rotting stems.

Clean water keeps those stems fresh and open, allowing them to continue absorbing it. It helps prevent decay, allowing your flowers to stay fresh and vibrant for longer. It also keeps those stems stiff and standing upright.

When you change out your water, remove the flowers and rinse out the vase thoroughly. Refill the vase with clean, fresh solution with plant flower food. Then, re-cut all the stems at a slight angle before returning them to the vase.

Re-cutting the stems is essential because, over time, the ends seal over and stop absorbing moisture. Every time you give them a fresh cut, you make it possible for them to absorb more water. Cutting them at a slight angle increases the surface area available to absorb fresh water.

Keep Them Cool

Did you know that florists store their flowers in a cooler while they are awaiting arrangement? Then, they return the arrangements to the cooler until you are ready to pick them up. There are several important reasons for this.

Cool temperatures inhibit the growth of bacteria. Bacteria thrive in warm, moist conditions, so keeping the water and surrounding air cool slows them down.

Your flowers also wilt more slowly when you keep the air and water cool. They continue to breathe after cutting, and this process occurs more slowly in cooler temperatures. This helps to reduce moisture loss and aging, keeping your blooms hydrated and fresh.

During the day, you’ll want to keep your flowers in a location where you can enjoy them. This isn’t always going to be the coolest room in the house. At night, you can move your flowers to a cooler room, such as a basement, garage, or refrigerator, to maintain their freshness for longer.

Be cautious about refrigerators, as fruits release a gas that shortens the lifespan of your flowers. If you have a second fridge that you don’t use for storing fruit, this is perfect. Otherwise, the refrigerator is a bad idea.

Stay Away From the Window

Finally, to make cut zinnias last longer, keep them away from direct sunlight, such as near a window. This is even more important in the summer.

Direct sunlight increases the temperature of both the air and the water around your flowers. It increases respiration, accelerating water loss and causing them to age faster. Warm water encourages bacteria to grow in the water, clogging stems and inhibiting water intake.

Similarily, warm air causes the flowers to dehydrate faster. Warm air and direct sunlight will dry out delicate petals, causing them to wilt and fall sooner, which is exactly what we want to prevent.

Apply this to the location in general. It’s not limited to windows. Always keep cut flowers away from heat sources. Appliances, such as the stove or a coffee pot, can put off heat and speed up the wilting process. Also, keep them away from ripening fruits, which emit ethylene gas.