Adam’s Needle/Yucca Gloriosa Variegata
At first glance, this Yucca looks very much like the similar Yucca recurvifolia ‘Marginata’: both have pointed leaves edged in gold, and both are native to the Southern USA. The differences become more marked as the plants age: the leaves of Yucca recurvifolia bend backwards (recurve), while those of Yucca gloriosa remain rigidly stiff and needle-like (although the outermost leaves do droop with age). Both of these evergreen plants are wonderful in the outdoor landscape, Adam’s Needle resembling a small tree in maturity, with leaves up to 50cm (18in) long. Although best planted in the garden border where it can reach its maximum potential, Adam’s Needle will thrive in a very large container. The flower spike appears on mature plants in late Summer and may reach a height of 2m (6ft): massed with bells of creamy white, it makes a very impressive sight.
Adam’s Needle is the most cold-tolerant species of all: the leaves remain coloured all year through and look good in any season – even if laden with snow. Keep the plant out of very cold winds if possible. Place this Yucca in full sun: the thick, fleshy leaves are able to withstand direct sunlight, and flowering is more likely on well-ripened wood.
Plants in pots or tubs should be watered thoroughly: then allow the surface of theto dry out before the next thorough watering. When the plant is not in active growth, give enough moisture to keep the compost moist without over-watering. Plants in pots will tolerate colder temperatures if the compost is on the dry side.
This tough plant has leaves with a waxy coating which prevents them from drying out. Therefore, it has no need of any additional humidity and thrives well in warm, dry-aired court-yard settings.
Feed established plants of Yucca gloriosa ‘Variegata’ every month during the growing period, using a proprietary plant food. If space is limited, use it at half the recommended strength.
Repot this plant in Spring until it is too large to handle easily. In this case, top-dress each Spring: remove the upper 5-7.5cm (2-3in) of old compost and replace with fresh compost to which has been added a small handful of slow-release fertilizer. Grow this Yucca in a free-draining, loam-based compost: add horticultural sand (up to a quarter by volume) to improve the drainage. The leaf tips of this Yucca are extremely sharp: take extra care when working around the plant, especially when repotting or top-dressing. Do not plant this Yucca, or place its pot, near where children play.
The lower leaves will die off naturally and should be allowed to fall of their own accord – only ‘help’ when they can be removed by gentle pulling.
Pests and diseases: Few attack these plants when grown outdoors, although sometimes Aphids can be a problem.