When to Plant Vinca Seeds for the Best Results

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

Also known as rose periwinkle or Madagascar periwinkle (Catharanthus roseus), annual vinca is a versatile little stunner with shiny green foliage and blooms of pink, white, rose, red, salmon, or purple. Although this plant isn’t frost-hardy, you can grow it as a perennial if you live in USDA plant hardiness zones 9 and above. Collecting vinca seeds from mature plants isn’t difficult but growing annual vinca from seed is a little trickier. Read on to learn how.

Vinca, also known as periwinkle, is a popular annual flowering plant that can brighten up any garden with its cheery blooms. But when is the best time to plant vinca seeds to ensure success? This guide will walk you through everything you need to know about timing your vinca seed planting for optimal germination and growth.

An Overview of Vinca

Vinca or Catharanthus roseus is a tropical plant that is native to Madagascar. It is an evergreen perennial in frost-free climates but is grown as an annual in colder areas. Vinca plants produce shiny green foliage and flowers in shades of white, pink, red, or purple. The blooms have five petals and often have an eye in a contrasting color.

Vinca does best in hot, humid environments and thrives in full sun. It can tolerate some partial shade but may produce fewer blooms. This heat-loving annual performs well in USDA hardiness zones 9-11 as a perennial but will bloom throughout the warm season in zones 2-8 when grown as an annual.

Factors That Impact Timing

Several factors impact when it is best to start vinca seeds indoors or sow them directly outdoors. Key considerations are the USDA zone you live in, your region’s last spring frost date, and whether you want to grow vinca from seeds or buy transplants.

USDA Plant Hardiness Zone

In zones 9-11, vinca can be planted in fall or early spring as a perennial. In cooler zones, it must be planted annually after all danger of frost has passed. Knowing your USDA zone is essential for proper timing.

Last Frost Date

The other crucial piece of information for timing is your area’s average last spring frost date Transplants or seeds should not be planted outdoors until after this date when nighttime temperatures will consistently remain above freezing

Seeds vs. Transplants

For earlier blooms, you can start vinca indoors from seed 10-12 weeks before your frost date. Or buy transplants and plant them outdoors 2-4 weeks after the last frost If sowing seeds directly in the garden, wait until 2-4 weeks after the frost date.

When to Start Seeds Indoors

Starting vinca seeds indoors gives you a head start on the season with earlier flowering. Follow these tips for timing your indoor seed starting:

Determine your last spring frost date and count back 12 weeks. This is when you’ll want to sow vinca seeds indoors.
Check the seed packet for the recommended soil temperature for germination (usually 70-75°F). Be sure you can provide warm enough conditions.
Plan to keep seedlings indoors for 8-10 weeks before hardening off and transplanting after all danger of frost.
Sow seeds in cell packs or trays with seed starting mix. Cover seeds lightly and keep the soil moist.
Move to full sunlight once sprouted. Pinch back tips for bushier plants. Harden off before transplanting.

When to Direct Sow Outdoors

If you prefer to sow vinca seeds directly in the garden, follow these guidelines:

Wait until 2-4 weeks after your average last spring frost date.
Check that soil temperature is at least 70°F for good germination rates.
Prepare the seedbed in full sun in advance by mixing in compost. Rake smooth and water lightly before sowing.
Sow seeds 1/4 inch deep and 6-12 inches apart outdoors once soil has warmed sufficiently.
Water gently to avoid washing away seeds. Keep soil moist for fast sprouting.
Thin seedlings or transplant to 10-12 inches apart when they are 2 inches tall.

Timing for Fall Planted Vinca

In zones 9-11, vinca can be planted in fall for gorgeous winter blooms. Follow these tips:

Start seeds indoors about 8 weeks before your average first fall frost date.
Harden off and transplant to the garden 4-6 weeks before the first frost.
Or direct sow seeds in the garden 6-8 weeks before your first fall frost date.
Give plants extra water as needed until they become established before winter arrives.
Mulch around the plants to protect the roots from cold damage during freezes.

When to Plant Vinca Transplants

For the easiest planting, you can purchase vinca transplants from nurseries and plant them in spring once the danger of frost has passed. Here are some tips:

Wait until 2-4 weeks after your last average spring frost date to plant.
Check transplants for disease, pests, or root damage before purchasing. Select stocky, green plants.
Harden off the transplants for 7-10 days by setting them outdoors in partial shade for a few hours each day.
Transplant into the garden in full sun, spacing about 12 inches apart. Water well.

Ongoing Care Through the Season

Proper care once your vinca is planted will keep it blooming happily all season:

Water when the top 1 inch of soil is dry. Avoid overwatering.
Fertilize every 2-3 weeks with a balanced flower fertilizer.
Remove spent blooms to encourage new flowers.
Scout for pests like aphids, whiteflies, and slugs.
In zones 2-8, replant annually after the last spring frost. In warmer zones, plants will return year after year.

Key Timing Takeaways

Following the right planting schedule helps ensure your vinca thrives and flowers abundantly. Keep these key timing tips in mind:

In zones 9-11, plant in fall or early spring. In cooler zones, plant as an annual after the last spring frost.
Start seeds indoors 10-12 weeks before your last frost for transplants. Move outdoors after hardening off.
Direct sow outdoors 2-4 weeks after the average last spring frost once soil is warm.
Plant fall vinca in zones 9-11 about 6-8 weeks before the first fall frost.
Transplant purchased plants after hardening off 2-4 weeks after the last spring frost.

With the right timing for your zone, vinca is easy to grow and will provide cheery blossoms from spring until frost. Pay close attention to your projected last spring frost date and plant vegetatively or sow seeds accordingly for best results.

when to plant vinca seeds

When to Plant Annual Vinca Seeds

Plant vinca seeds indoors three to four months before the last frost of the season. Cover the seeds lightly with soil, then lay a damp newspaper over the tray because germinating seeds of vinca require total darkness. Place the seeds where temperatures are around 80 degrees F. (27 C.). Check the tray daily and remove the newspaper as soon as seedlings emerge – generally two to nine days. At this point, move the seedlings into bright sunlight and room temperature is at least 75 degrees F. (24 C.).

How to Gather Vinca Seeds

When collecting vinca seeds, look for long, narrow, green seedpods hidden on the stems beneath blooming flowers. Snip or pinch the pods when the petals drop from the blooms and the pods are turning from yellow to brown. Watch the plant carefully. If you wait too long, the pods will split, and you’ll lose the seeds. Drop the pods into a paper sack and place them in a warm, dry spot. Shake the bag every day or two until the pods are completely dry. You can also drop the pods into a shallow pan and put the pan in a sunny (non-windy) location until the pods are completely dry. Once the pods are completely dry, open them carefully and remove the tiny black seeds. Place the seeds in a paper envelope and store them in a cool, dry, well-ventilated location until planting time. Freshly harvested seeds usually don’t do well because germinating vinca seeds require a period of dormancy.

Planting Vinca Seeds Periwinkle Catharanthus

FAQ

What month do you plant vinca?

Vinca/Myrtle/Periwinkle

Plant name	Zone	Plant seedlings/transplants outdoors (spring/fall)
Vinca/Myrtle/Periwinkle	9a	On/around March 15 (after last frost)
Vinca/Myrtle/Periwinkle	9b	On/around March 15 (after last frost)
Vinca/Myrtle/Periwinkle	10a	Not recommended
Vinca/Myrtle/Periwinkle	10b	Not recommended

How long does it take to grow vinca from seed?

Raise Seedlings

Seeds should germinate in around 10-15 days at a soil temperature of 24-26°C. Transplant seedlings to the garden once they have their first true leaves and are large enough to handle (usually 5-10cm tall). Plant out, spacing plants 30cm apart.

Do vincas come back every year?

Links

Annual Vinca:

Vincas, especially the annual varieties like Catharanthus roseus (Madagascar periwinkle), are commonly treated as annuals, meaning they are planted, grow, bloom, and then die back at the end of the growing season.
Self-Seeding:

However, many vinca varieties readily self-seed, meaning they drop seeds that can germinate and grow into new plants the following year.
Return the Next Year:

If you have vincas in your garden, you might see new seedlings popping up the following spring, indicating successful self-seeding.
Propagating Vinca:

If you want to ensure you have vincas every year, you can also propagate them by taking cuttings in the fall and rooting them indoors, then planting them out in the spring.
Vinca Minor (Periwinkle):

It’s important to note that there are also perennial vinca varieties, such as Vinca minor (periwinkle), which are evergreen and can survive through the winter.

How many vinca seeds per hole?

Sow seeds in rows in the container or 3 to 4 seeds per cell. Cover the seeds completely with 1/4 inch of the mix; press the mix down lightly and spritz the surface with water to moisten it and settle the seeds.

How do you plant vinca?

Prepare the planting container: Fill a planting tray or small pots with a well-draining potting mix. Vinca prefers soil with good drainage to prevent root rot. Sow the seeds: Place two or three Vinca seeds on the surface of the soil in each pot. Do not bury the seeds as they require light to germinate.

When should I plant vinca?

In colder regions, it is best to wait until all danger of frost has passed and the soil has warmed up before planting vinca outdoors. This is usually in late spring or early summer. If you prefer to start vinca from seeds, you can start them indoors about 10 to 12 weeks before the last expected frost date.

When do Vinca seeds grow?

Once the seeds have germinated, they will start to develop into seedlings. When should I plant vinca seeds? Vinca seeds can be planted indoors 8-10 weeks before the last frost date in your area, which will give them enough time to germinate and grow before the outdoor growing season begins.

Can you plant vinca seeds indoors?

To get vinca flowers blooming as early as possible in summer, the seeds need to be started indoors. Here is a complete guide to sowing and planting vinca seeds. Vinca seeds should be started indoors 12-15 weeks before your last expected spring frost date. This gives the seedlings time to develop strong root systems before being moved outside.

Can you plant vinca seeds before planting?

Before planting the Vinca seeds, you can pre-soak them in water for a few hours to help speed up the germination process. This step is optional, but it can be beneficial, especially if the seeds have a hard outer coat. Once the seeds are pre-soaked, you can plant them in the soil mix.

How long does Vinca take to germinate?

Vinca, also known as periwinkle or Catharanthus roseus, is a popular flowering plant that is often grown from seeds. Germinating Vinca seeds can be an exciting process, but it requires patience and careful attention to produce healthy seedlings. In general, Vinca seeds take about 10 to 14 days to germinate.