Common periwinkle

Year-round

Lesser periwinkle is a low, trailing evergreen groundcover that spreads by rooting stems; in the Houston area it does best in shaded to part-shade beds where summer heat is less intense.

• Plant in part shade to full shade; Houston's hot, humid summer sun can scorch the foliage.
• Water regularly through the first growing season to establish; once rooted it tolerates dry spells.
• Shear or mow lightly once a year to keep growth dense and manage its spread.
• Reported toxic to dogs, cats, and horses if ingested, per the ASPCA, so keep pets that chew on foliage away from the bed.

Kept edged and mowed low, it reads as a tidy shaded groundcover rather than an unmanaged spread, which keeps it HOA-friendly.

Fall

Growth slows as temperatures cool; fall is a good window for a light trim and new plantings.

• Cooler, milder fall weather is a good window for planting new periwinkle divisions.
• Reduce watering as the weather cools and rainfall picks up.
• Clear fallen leaves off the bed so they don't smother the low foliage.

Winter

In the Houston area periwinkle stays evergreen through winter with only occasional frost damage during hard freezes.

• Foliage may brown after a hard freeze but typically resprouts as temperatures warm.
• Hold off on major pruning until freeze risk has passed for the season.
• Keep the bed on the drier side while growth is slow through winter.

A frost-browned patch can look ragged; a light shearing once freeze risk passes restores a tidy appearance.

Spring

Spring is bloom season and a good time to tidy up winter-tattered foliage and expand plantings.

• Shear back any winter-tattered foliage in late winter to early spring to make room for fresh growth.
• Watch for violet-blue flowers appearing through the foliage in March and April.
• Divide and replant crowded sections if you want to expand coverage elsewhere in the bed.

Summer

Houston's summer heat and humidity are the toughest stretch for periwinkle; consistent shade and moisture keep it from scorching.

• Water during dry stretches, especially in beds that get any afternoon sun.
• Watch for fungal leaf spot in humid weather; thin dense mats to improve airflow if it appears.
• Keep it edged back from walkways and turf so it doesn't spread past the bed.