The lilac is a flower renowned for its springtime blooms, beloved for its scent and notorious for not lasting very long. Lilacs tend to droop within a few hours if not properly taken care of, but with a bit of extra love, you can extend that life.
This post will explain how to keep cut lilacs from wilting in a vase and in other arrangements, and then offer a lilac FAQ with some suggestions for longer-lasting varieties to try.
How to Keep Fresh Cut Lilacs from Wilting
The first step to keeping your lilacs looking great is to cut them at the right time. UMass Extension states that the ideal time to cut any flower depends on “pre-harvest” factors like flower maturity stage, “weather conditions and plant environment.” Even the time of day you cut a flower will affect its vase life.
They explain that flowers should be “properly watered” beforehand “so that the cell walls are turgid.” Water-stressed flowers won’t last as long, while flowers that have been through a recent downpour could be splattered with soil and microbes that could lower their vase life.
How to Harvest Lilacs
Harvest flowers in the morning or evening, but preferably in the morning, “when temperatures are low and plant water content is high,” says UMass. As soon as they’re cut, place them in water to reduce stress.
Stephanie Lindemann of the Chicago Botanic Garden suggests taking a cool bucket of water with you when you cut so you can immediately put your stems in water.
The bucket should be disinfected so no bacteria or fungi can contaminate your freshly cut blooms. Aim to have at least a few inches of water in the bucket, depending on how many flowers you plan on cutting.
Cut lilacs with clean, sharp shears. Choose long stems, since you’ll be recutting these at least a couple of times. Cut the stems at a 45-degree angle and put the flowers right in the bucket. Soak them “for at least an hour,” says Lindemann, keeping the bucket somewhere cool and dark while the stems soak.
How to Prepare Lilacs
Once soaked, prepare the flowers. Remove any leaves that will sit below the water line. Leaves below the water line will quickly decay, attracting all kinds of unhealthy microbes and clogging up the water. If you like the look of the leaves, keep a couple of them near the flower itself or cut a separate stem just made up of leaves so your flower stem can focus on hydrating the flower.
Next, trim the stem to increase water intake. Some gardeners and florists recommend making two perpendicular 1-2 inch vertical cuts in the stem end so the stem end forms 4 pieces. Some recommend smashing the stem end with a hammer, although not everyone agrees on that method.
Lindemann suggests making one vertical cut to the stem end and then twisting it back. Whichever method you choose, cut the stem underwater to minimize air bubbles that can block water and nutrient uptake.
How to Keep Lilacs from Wilting in a Vase
Cut lilac care is similar to any cut flower care—keep the environment clean and keep the flower drinking. Your goal is to keep bacteria and other microorganisms at bay and to make sure your lilacs can stay hydrated as long as possible.
Choose a clean vase to start with. Dirt particles and bacteria can clog flower stems, limiting the amount of water cut flowers can uptake, while microorganisms in the water can speed up decay. Rinse your container with vinegar or bleach prior to using it to kill any lingering bacteria.
Place your finished arrangement in a cool, relatively humid environment. Keep lilacs away from direct sun and heat, especially in the form of registers and baseboard heaters, which will dry them out.
Lilacs are sensitive to ethylene gas (the gas that fruits and veggies release as they ripen). As with most cut flowers, ethylene will speed up decay in your lilacs, so if you keep your flowers in the kitchen, store your fruits and veggies in the fridge.
Lilacs are thirsty flowers, so keep the water level high. Check the water every day and change it often—ideally, every day. Trim the stems every other day using one of the methods outlined above.
There are a few additives you can use to keep lilacs fresher longer. The first is an additive to lower the pH of the vase water. UMass states that “flowers absorb more water in acidic solutions than those at higher pH levels,” which is why many florists use citric acid or another chemical to keep pH levels lower.
Analyze your water first to determine your starting pH. Then follow the directions of any product you use to get the dilution right.
In addition, many folks use a touch of bleach or an antibacterial agent, which acts as a biocide for microorganisms. You can also find slow-release chlorine tablets on the market, as an alternative.
The third additive is a carbohydrate like sugar. Sugar gives plants the energy they need to maintain their basic health and to develop flowers.
Commercial flower foods will contain all three of these additives (carbohydrates, biocides and acidifying agents). Many people prefer to DIY their own additives because it’s more cost-effective, but there is a convenience to having the guesswork taken out of the recipe.
How Do You Make Cut Lilacs Last Longer Outside of a Vase?
For weddings and special events, your lilacs might need to hold up in less than ideal conditions. In addition to the care and cutting tips above, there are a few tips and tricks to making your lilacs look fresh when you need them.
First, keep them in water as long as possible. Make removing them from water the last thing on your to-do list, if you can.
Second, if you plan on a wedding bouquet or a boutonniere of lilacs, have a few strategic vases of cool water mixed with flower food scattered around your venue so you can give your flowers a quick drink whenever possible.
Third, keep a pair of sharp shears next to the vases so you can trim them up before letting them drink.
Finally, keep them out of sunlight and away from heat as much as possible. Tuck those strategic vases somewhere shady and cool.
Common lilacs (Syringa vulgaris) have the longest blooming season, blooming for 16-20 days, according to Montana State University Extension.
The average vase life of a lilac can be anywhere from 3 days to 2 weeks. Exactly how long lilacs last depend on the species and the cultivar, as well as the care the lilac gets.
Gardening guru Sarah Raven casts her vote for Syringa vulgaris ‘Madame Lemoine,’ which she says lasted 9 days and won her vase life trial. She says the “complexity” of double lilacs make them more durable when they’re cut.
As an alternative, the Missouri Botanical Garden proposes Syringa vulgaris ‘Président Grévy’ as a good cut flower.
Not really. Lindemann explains that once cut, lilacs don’t open very much, so she recommends choosing “stems that have at least three-quarters of the flowers open.”
And now you know how to keep lilacs from wilting after cutting. Best of luck with your lilac blooms!