Ilex crenata 'Mariesii' grows into a wonderfully congested form of small leaves held tightly to the stem.

WHAT: The Sky Pencil variety of ilex crenata is a narrow columnar Japanese holly that has dark, lustrous evergreen foliage. In the fall, it produces purple berries that attract birds.

When planting an Ilex crenata, he said it was important that the soil was patted down firmly to avoid creating air pockets. Love Your Weekend with Alan Titchmarsh airs Sunday on ITV at 9:30am.