Sometimes called the Vinca flower, periwinkles have a reputation for being easy to grow. They thrive in many conditions, making them accessible to gardeners of any skill level.
I wanted to figure out how I could grow periwinkle in a pot in my container garden. Below you’ll find all the details that can help you grow them as well.
Choose the best time to grow periwinkle
Periwinkles are a versatile plant that’s easy to grow. In fact, the plant grows so abundantly that many consider it to be invasive.
Most of us associate the periwinkle with the colorful purple flower and evergreen foliage. However, there are several distinct periwinkle species. Some will grow short, making it good for ground coverage. Others will have trailing vines that look great in baskets.
Whatever you choose to grow, the needs of these plants are very similar.
Generally, periwinkle plants are best when started in the spring or fall. There’s no exact timeline to guarantee success. Most recommend that you start early in the year as soon as the soil is workable. That means after your last frost when temperatures are more stable.
Where Does Periwinkle Grow?
Here’s the beauty of the periwinkle: it grows just about anywhere. It does best in hardiness zones 4 through 11. However, many gardeners report success as far north as Canada.
Another interesting thing is that the plant’s lifespan will vary based on where you live. In colder regions, the plant acts more like an annual. It will grow fast and complete its growth cycle within the year.
But in hotter regions, your plant may continue to grow beyond a year. In those areas, the plant acts more like a perennial.
Understand how long it will take to grow
These plants don’t take very long to grow. Periwinkles will fill a pot and have lengthy vines within a year. Most of the growth will occur during the spring and summer months. But, they are also drought tolerant and can resist cool weather.
Thus, continued growth is very common.
Periwinkle plants are not climbers. Contrary to popular belief, the branches and vines will not grow up a lattice or wall. Instead, the vines will spread out wide. Only a few months after planting, the vines should start to drop off the sides of the pot. If planted in the ground, they will start to spread and cover the soil.
All that said, you may experience different results depending on how you start your plant. These days, most gardeners opt for propagated plants from a nursery. That’s because growing from seedlings extends the growth cycle significantly.
Even germinating the seeds can take as long as three weeks. In those cases, you’d have to start early and wait a bit longer to experience significant growth.
When Do They Bloom?
The broad-leaf vines of the periwinkle plant are beautiful in their own right. But when do those gorgeous flowers start appearing?
In most cases, periwinkles will start to bloom in early spring. March and April are the most colorful months. If you live in a temperate region, you may also see an additional blooming period in the fall.
While these plants love the summer heat, the flowers are a bit more delicate. So, they typically don’t bloom in the summer.
Choose the right pot to grow periwinkle
Perwinkle thrives in containers and pots. These plants can spread quite rapidly. For this reason, it’s best to not grow them in a garden. On the ground, the plant can quickly spread and overtake other plants. But in a pot, the beautiful plant stays contained and manageable.
The first thing you’re going to need to do when starting a periwinkle plant is to choose a suitable pot. Here are some important factors to consider.
When it comes to pot size, periwinkles are quite versatile. Generally, these plants need about 8 inches of space between them when planted in the ground. That’s enough space to ensure that the roots do not mingle and impact plant growth.
A pot that’s 8 inches wide and roughly 6 inches deep will do just fine. The base of the plant will only grow to about 6 inches tall. However, the vines can stretch 18 inches or longer. So, you need to consider the plant’s spread.
Despite the vine growth, there’s no need to support them with a larger pot. They do just fine hanging off the side of the container.
Any standard pot will work for periwinkles. But, the nature of the vines can present some problems if you’re not careful.
I recommend finding a pot that can sit off the ground. You can plant it in a pot with a stand or even use a hanging basket. The goal here is to ensure that the vines don’t sprawl across your deck or rooftop terrace. Lifting the pot off the floor ensures that the vines fall down rather than out. Plus, it creates a beautiful display.
There’s no hard requirement when it comes to pot material. Standard plastic, terracotta, or ceramic pots are fine. However, you may see better success with organic material like coconut coir.
It all comes down to drainage. Periwinkle does not tolerate sitting water. With a coir basket, you can rest easy knowing that the soil can drain adequately after watering.
Prepare the pot for planting periwinkle
Once you have your pots, there is still some preparation to do.
As I mentioned earlier, proper drainage is a must with these plants. Take a moment to ensure that your pot can get rid of excess water without any problems.
There should be a few drainage holes on the bottom. A single hole in the center will not suffice. It’s a good idea to drill a few more around the perimeter to be on the safe side. Otherwise, you run the risk of experience fungal issues and root rot.
Next, figure out where your plant is going to live. I’ll go over sun requirements in a bit. For now, think about elevation.
Setting the pot on the ground is not a good idea. Not only will the vines get in the way, but the flooring surface could seal the holes up. Find a stand to prop your pot up. If you have a hanging container, ready your anchors or brackets.
Thanks to the hardy nature of periwinkles, you don’t have to do any major prep work with the soil. These plants can grow in standard commercial potting soil. Go for a formula that focuses on flowers or houseplants.
If you want to start your plant off with a boost of nutrients, you can amend the soil with compost. Just add some organic compost and work it in.
Whether you add compost or not, it’s good to till the soil a bit. Loosen it up with your hands or a garden trowel to make sure that there are no hard bits. The last thing these plants need is compact soil that can’t drain properly.
Plant the periwinkle from cuttings
Now it’s time to start planting. How you will proceed depends on the planting method you choose.
Planting from Bare-Root Plants or Cuttings
The easiest and most common method is to use bare-root plants or propagated cuttings. You can find young plants and roots at most nurseries.
This planting method is quick and easy. At this point, the propagation has had some time to develop a bit at the nursery. As a result, there are fewer risks of issues.
Start by filling the pot with soil. Then, dig a hole that’s about 3 to 4 inches deep. The hole should be just as wide.
For bare-root plants, you’ll need to work fast and keep the root system hydrated. Gently remove it from the bag and give the root a good spritz of water.
Place the root mass into the hole and position the tiny tendrils so that they face downward and outward. Fill the hole around the root with loose soil. Use your hands to lightly pack the soil. You don’t want the soil to be a bit firm to keep the root and existing stem in place.
For young periwinkle plants, the process is very similar. The only difference here is that you’re going to transplant it rather than moving the bare root.
Dig a hole that’s about the same size as the container the plant came in. Gently remove the plant and its soil. Then, place it in the soil and give it a good watering.
Starting from Seed
Starting your periwinkle plant from seed is not easy. It takes longer and requires more attention. But, this method does offer greater control.
It’s best to start seeds about 12 to 15 weeks before the last frost. You need to germinate the seeds indoors where temperatures are between 75 and 78 degrees Fahrenheit.
I recommend planting the seeds directly in the pot you want to grow. It just makes things easier and eliminates some work later on. You can grow in seed trays, but you will need to thin the plant and transplant it once it gets bigger.
Place the seeds on the surface of the soil. Then, cover them with a fine layer of your potting mix. Keep the seeds moist and warm as you wait for them to germinate. Seedlings should emerge in 14 to 21 days depending on the growing conditions.
Provide the required sunlight to the plant
Here’s where growing periwinkle can get a little tricky. These plants can thrive with full sun. But, they can also do very well in partial shade. The right amount of sun for your plant will depend entirely on your goals.
In partial shade, the plant will produce healthier and greener foliage. Periwinkles are evergreen plants, so the quality of the foliage is more important than most plants. You want it to look good all year long, right?
For partial shade, put the plant in an area that gets 3 to 6 hours of sun each day. Typically, plants in hanging baskets will always get partial shade. At some point, the wall or pole the basket is on will cast a shadow.
Now, if you want full sun, put the plant on the south side of your home. Pick a spot that has full exposure to the sun’s rays regardless of the time of day.
In full sun, the periwinkle plant will produce more flowers. The quality of the foliage may suffer, resulting in a more yellowish hue. But, the pop of color from the blooms will make up the difference.
Many gardeners like to move their periwinkle plants to get the best of both worlds. You can put the plant in the full sun early in the spring to develop more flowers and move it to partial shade for the rest of the year.
Water the periwinkle in the pot
Periwinkle plants do not need as much water as most people think. They like to stay hydrated, but they are surprisingly drought-tolerant.
One thing these plants do not enjoy is overwatering. They are susceptible to root rot and can quickly develop fungal problems if you go overboard with the hydration. For this reason, it’s best to err on the side of caution when watering.
There’s no exact science to watering periwinkle plants. It all depends on the weather and the quality of the soil.
You want the top 2 inches of soil to dry out before you water the plant. Use your finger to check. It’s better for the soil to be on the dry side rather than over-saturated with water. Chances are, you’ll only have to water the plant once every other week or so.
When the soil is dry enough, water the plant to a depth of about 6 inches. Aim for the base of the plant and do your best to avoid getting any water on the foliage.
The best time to water the plant is before dawn or in the very early morning hours. The plant needs plenty of time to take advantage of the water. But, the excess water should have all day to evaporate. If it’s already past noon, wait until the next day to water the plant. Late waterings will increase the chances of fungal diseases attacking the plant.
Prune the periwinkle plant
Pruning is an essential task that can help your plant reach its full potential. Periwinkle plants grow rapidly, so they require more pruning than other plants.
The first pruning session should occur in the early spring. Prune the plant immediately after the last frost to about 4 inches tall. Use sharp shears and cut the lengthy vines at an angle.
This pruning job will keep the spread of the plant more contained. The vines will still grow. But, pruning will help to prevent overgrowth and ensure that blooms occur throughout.
Throughout the spring season, trim off spent flowers. This process, known as deadheading, will tell the plant that it needs to continue blossoming. If you fail to remove dead flowers, the periwinkle may stop producing flowers much earlier in the seasons.
If your plant gets a bit too unruly for your liking, you can also trim back vines as they grow. The plant is hardy and usually doesn’t respond negatively to pruning during the spring. Cut the vines at their origin. Doing this will make the plant more full, which is always a nice plus.
Finally, the last pruning session can occur in late summer. This pruning job is only necessary if the plant gets too overgrown. Just trim the vines and stems back to about 6 inches.
Never prune in the Fall or Winter. Doing so will make the plant more vulnerable to the colder temperatures.
Fertilize the periwinkle plant
Chances are, your periwinkle won’t need a ton of fertilizer to grow. These opportunistic plants will spread regardless.
However, regular fertilizer applications can benefit the plant in many ways. After the first prune of the year, fertilizer can kickstart new growth and ensure that the plant develops enough to produce blossoms.
Not only that, but fertilizer can improve the quality of the foliage and flowers. The goal is to have green waxy leaves and vibrant blooms. Proper fertilization will help you get there.
You don’t need a fancy or complex fertilizer product. A balanced product works just fine. Balanced fertilizers contain an equal amount of nitrogen, phosphorus, and potassium. You may see these products labeled as 10-10-10.
Choose a water-soluble formula and prepare the mixture according to the instruction. Then, water your plant like you normally would. It’s that easy.
Monthly applications are best for periwinkle plants. This is especially true during the spring when the plant experiences the most growth. You can cut back a bit after the summer. But, continued applications will help maintain the foliage after blooming stops.