Catharanthus (Catharanthus roseus) is commonly known by many different names including periwinkle, Madagascar periwinkle, rose periwinkle, annual vinca, and vinca.
It’s an evergreen (some varieties are annuals) spreading shrub that creates a 4-feet tall tidy mound that is covered throughout the summer with small colorful blooms.
When not in bloom Catharanthus has interesting glossy green foliage year-round (if an evergreen perennial).
This is a drought-tolerant flowering plant that makes an easy-care bedding or border plant that never needs dead-heading.
How To Grow Catharanthus
After the soil has been broken up, add 2-3 inches of compost on top of the soil and lightly turn it under the soil and rake the surface smooth.
If the catharanthus will be grown in a container, select a container that is at least 12-inches deep and wide to give the plant plenty of room to grow.
Use a good quality potting soil that contains compost and fill the container to within 1-inch of the top rim.
The compost will help keep the plant fed, prevent soil compaction, improve drainage, and invite earthworms to the soil to further improve the soil structure and fertility.
Plant seeds in early spring and space seeds 1-foot apart in all directions, cover with 1/2-inch of soil and water gently until the soil is saturated. Keep soil moist until the seeds germinate.
When planting seedlings, dig the hole two times larger than the root ball and deep enough that the plant will be at the same level in the ground as the soil level in the container.
Push the soil gently around the roots filling in empty spaces. Firm the soil around the plant by hand and water thoroughly.
Water, Lighting, and Soil Needs
Water the newly planted seedling daily for the first two weeks and keep soil moist if you’ve planted seeds for 2-weeks past germination.
After that, watering can be reduced to every other day or every third day depending on the weather conditions. Water at the base of the plant not from above to avoid getting the foliage wet.
Container-grown plants will dry out quicker than in-ground plants, so daily watering may be required throughout summer.
Catharanthus is drought and heat-tolerant and will survive if you forget to water it for a few days once the plant has become established.
This attractive plant is not picky about the lighting. It will thrive in direct sunlight or dappled sunlight. As long as the plant receives at least 4-hours of bright light each day it will be fine.
Catharanthus prefer to have their roots in slightly acidic soil but they will tolerate any soil conditions except poorly draining soil that remains soggy.
Use a plant food that is formulated to encourage blooms for the longest-lasting bloom season on your catharanthus. Whether it’s organic or synthetic, use one that comes close to a 5-10-5 ratio.
Over-fertilizing the plant will do more harm than good, so follow the recommended dosing instructions for best results.
How To Use In Garden Or Landscape
Catharanthus is typically used as a foundation plant and positioned among shrubs but that’s not the only way to use this colorful perennial plant.
Depending on the variety planted, this prolific bloomer is ideal for hanging baskets, planters, window boxes, and borders.
The plants can be pruned to keep them at the desired size and to encourage more blooms. Anywhere a pop of floral color is desired in the landscape, Catharanthus is a flowering plant that won’t disappoint.