Snapdragons are easy to grow and will add vibrant color to any flower bed. So named because the many individual blooms on their lavish flower heads look a bit like the snout of a mystical dragon, they stand out beautifully in any spring or fall garden.
Beautiful snapdragon flowers will bloom profusely in cool weather. These gorgeous flowering plants often stop blooming in the intense heat of mid-summer. But if you keep watering them consistently, and keep the soil moist, they will flower again in the fall. In cool climates, they will bloom throughout the summer.
What time of year do snapdragons flower?
The snapdragon, Antirrhinum majus, is native to North Africa, parts of the Middle East, and the Mediterranean region.
They are winter-hardy flowering plants in the U.S. Department of Agriculture (USDA) Hardiness Zones 7-10, and technically an herbaceous perennial. But most U.S. home gardeners grow them as an annual rather than a perennial.
Snapdragons are available in a wide range of varieties, sizes, and colors.
Some tall varieties will reach up to 4 feet tall, while dwarf varieties seldom grow more than 6-10 inches tall. Medium-sized plants will often grow about 2 feet tall.
They come in every possible color except for a true blue. Bicolored flowers usually have a white throat while the bottom lip of the flower, which pollinators open when they reach inside for pollen, is another color.
They usually bloom in spring, from April until there is frost in late fall. In warmer zones 9-11, if plants set buds before the first frost, they will often bloom throughout the winter months.
Factors that affect snapdragons from blooming
There are many factors that come into play, starting with when and where you plant your snapdragons. If you get this right, you are halfway there.
But, of course, conditions in your garden should also be right to ensure your snapdragons grow into healthy plants that produce as many blooms as possible for as long as possible.
When to Plant Snapdragons
The best snapdragon planting months in warmer climates are April and September if you live in USDA zone 7, and February, March, and October to December in zone 9. February, November, and December are the best snapdragon planting months for those living in zones 10-11.
If you live in a colder region, it’s a good idea to sow seeds indoors. When snapdragon seeds are started indoors, you will be able to transplant them in your flower bed when the danger of heavy frost has passed.
You will see the seed starting to sprout in about 8-14 days.
Snapdragons can tolerate light frost but will need to be protected from hot sun and wind until they are established.
Where to Plant Snapdragons
Snapdragon flowers do best in locations that get full sun for most of the day. They thrive in rich, moist, organic soil that drains well.
Young snapdragons do best in cool weather, which is why it’s best to plant them in winter in very warm regions. But they bloom best in the cool temperatures of late spring or early summer.
Generally, they do best when daytime temperatures are in the low 70s (°F) and night temperatures are in the low 40s.
Some people maintain that the right amount of sunlight is the key to getting snapdragons to flower. They suggest adjusting the amount of sun!
Of course, unless you have chosen the perfect spot for your snapdragons that gives some sun and some shade, the only way to do this is to grow them in pots and move them around. Our advice is to play it by ear, and if they don’t flower well, rethink their location for the next growing season.
Snapdragons need light to germinate. Once they have sprouted and are growing, they prefer full sun that provides lots of light but will usually bloom in partial shade.
In warm areas, if you plant them in partial shade and keep them watered well, they will usually stop flowering in summer but will bloom again in the fall.
It’s important to keep the soil in your snapdragon flower beds evenly moist. You don’t want it to become waterlogged.
Generally, they need about an inch of water per week, either from rain or irrigation. It’s a good idea to use a rain gauge to check how much rain you have had.
The best way to water snapdragons is to use a drip or trickle system, or to lay your hose flat on the ground. If you do water from above, water early in the day so that the foliage dries off. This will help to minimize disease problems.
Once your snapdragons are well established, you can let the top inch of soil dry out completely before each watering – although obviously, you won’t be able to control this if you experience rainy weather.
Snapdragons aren’t heavy feeders. They do best in soil with a neutral pH of between about 6.2 and 7.0 that is fertile and drains easily.
Adding compost and any good quality organic matter will help to keep them blooming.
Fertilizer & Mulch
Apply a standard, all-purpose fertilizer like a 10-10-10 product once the plants start to produce flowers. Usually, 3 lbs for every 100 square feet of groundworks well.
Be sure to water well after applying the fertilizer to help it reach the roots of your flowering plants and minimize any risk of nitrogen burns.
Adding a nice thick 3-4 inch layer of mulch will help to keep the soil moist and will also help to stop weeds from growing. Weed-free straw is a good option.
Clean up the Flower Bed After the Growing Season
After the growing season, cut the plants down to the ground. If you leave some of the spent flowers in the flower bed you will encourage reseeding without having to sow seeds.
In more moderate climates, you can leave the plants that don’t die back. They will usually develop into strong, healthy plants in spring.
How long do snapdragons bloom?
This depends on your local climate and garden conditions. In most areas, they will continue to bloom until temperatures rise above 80°F (26.6°C).
In cool climates, they often bloom from late spring throughout the summer into the fall. In mild, warmer climates, they will sometimes bloom throughout the winter months.
If you want your snapdragons to keep on flowering, cut them back a little once the first flowers stop blooming. Also, remove spent blooms by deadheading them as soon as the flowers start to fade. This will encourage more flowers rather than the plant expending energy on producing snapdragon seeds.
How do you get snapdragons to bloom?
When your snapdragons are about three inches tall, pinch the foliage back to encourage them to branch and promote the growth of new leaves. Be sure to trim any dead bits too.
After your first batch of snapdragon flowers, cut the plants back by one- to two-thirds so that they are only a few inches tall.
Why are my snapdragons not flowering?
If your snapdragon plants stop flowering suddenly, it may be because the weather is too hot. Or it may be because your flower bed gets too much shade.
It is very common for them to stop producing flower heads with the onset of hot summer weather. Even though they will usually tolerate light shady conditions, they do much better in full sun.
Another reason snapdragons stop flowering is that, as mentioned above, they start to set too much seed.
The National Garden Bureau advises snapdragon growers to remove dead or spent flowers to ensure that the flowers keep setting (or initiating). As they say, if the plants set too much seed, they will tend to peter out and stop flowering.
The snapdragon was one of the Bureau’s “Year Of” plants in 2019.
What to do if your snapdragons don’t bloom?
Usually, snapdragons will flower again when the weather cools off towards the end of summer. Cut back the old flower stalks to encourage this.
Also, be sure to keep them watered throughout the heat of mid-summer.
When they do bloom, cut the flowers often. You will always have a fresh vase of flowers in your home, and they will encourage them to keep on blooming.
If snapdragons are happy and healthy, they can potentially flower all year long. But this seldom happens because climatic conditions play a role.
Nevertheless, these snapdragon garden tips for 2023 will give you a good idea of when yours should flower and for how long.
Certainly, there are factors that affect whether snapdragons will bloom and when they will bloom. By familiarizing yourself with these factors before you plant your snapdragons, you are more likely to have a colorful fragrant flower bed packed with beautifully blooming snapdragons.
Whether you grow them for cut flowers or to have an ongoing display of color in your garden, our tips will help you achieve your goals.