Periwinkle in May: monthly care

Periwinkle thrives in partial or full shade, making it an excellent choice for difficult areas under trees or along north-facing borders where many other plants struggle. It tolerates a wide range of soil types but performs best in loam or clay soil that retains some moisture without becoming waterlogged. Before planting, clear the area thoroughly of perennial weeds—once established, periwinkle's dense mat makes weeding difficult. Plant periwinkle in March, April, May, September, or October, when the soil is workable and temperatures are moderate. Autumn planting is particularly successful, as it allows roots to establish before winter. Space plants 30 cm apart; they will spread steadily to form a continuous carpet, with individual plants eventually reaching 60–150 cm across. Dig a hole slightly larger than the root ball, ensuring the crown sits at the same level it was growing in the pot. Firm the soil gently around the roots to eliminate air pockets. Water thoroughly immediately after planting to settle the soil and encourage root contact. For the first growing season, keep the soil consistently moist but not saturated, especially during dry spells. Periwinkle has moderate water needs and will establish more quickly with regular attention in its first year. Apply a 5 cm layer of organic mulch around the plants, keeping it clear of the stems, to suppress weeds, retain moisture, and improve the soil as it breaks down. Once the plants begin to spread and knit together, they will suppress most weeds themselves and require far less intervention.

Once established, periwinkle is remarkably low-maintenance and tolerates neglect better than most groundcovers. Watering is rarely necessary except during prolonged dry spells in summer, particularly in the first year or two. Periwinkle has moderate water needs and copes well with typical rainfall in temperate climates. If the leaves start to wilt or look dull, give the planting a thorough soak rather than frequent light sprinkles. Feed periwinkle once a year in April with a balanced general-purpose fertiliser or a light dressing of well-rotted compost or blood, fish, and bone. Scatter it evenly over the foliage and water in if rain isn't forecast. Avoid overfeeding, which can promote excessive leafy growth at the expense of flowers and make the plants more prone to disease. Periwinkle grows well in relatively poor soil, so a single spring feed is sufficient. As an evergreen hardy to zone 4a, periwinkle requires no special winter protection in our region. The foliage remains green throughout the year, providing valuable ground cover and weed suppression even in the coldest months. Top up mulch in autumn if the layer has thinned, but keep it away from the stems to allow air circulation. Periwinkle is generally pest- and disease-free, though it can occasionally suffer from rust or leaf spot in very damp, poorly ventilated conditions. Remove and bin affected leaves promptly. Slugs and snails rarely bother it. The main "problem" with periwinkle is its vigour—it can become invasive in small gardens, so site it carefully and be prepared to trim back spreading stems annually to keep it in check.