Why Is My Hardenbergia Wilting?

Basic Soil Requirements

• For the lilac vine to grow well, it needs a moist but well-drained soil. Sand, loam and clay soils that are not alkaline in pH all are acceptable garden soils. The key is a well-drained soil, even though lilac vine's roots are rather shallow, growing in the top 12 inches. If the soil is either bone-dry or soggy wet, wilting can result. Overly wet soils inhibit oxygen from reaching roots, which leads to root suffocation and often a bout with some fungal root rot disease. As the roots die, less water uptake occurs, causing above-ground foliage and stems to wilt. In the case of overly dry soil, the roots simply cannot locate ample moisture to keep the foliage from wilting.

New Plantings

• Newly acquired lilac vines, which are grown and sold in containers from nurseries and garden centers, need to be planted in appropriately moist but well-drained garden soil. The vine must be regularly watered to maintain an evenly moist soil until the roots in the original root ball mass finally grow outward into the garden soil. Water enough to maintain the original root ball as moist, but also keep the surrounding planting hole's soil equally moist. This creates a consistent profile for the roots to readily grow through to establish the plant in the new environment.

Drought Tolerance

• When newly planted, the lilac vine demonstrates little drought tolerance. Once its roots spread out from the original root ball, the plant tolerates moderate drought before it succumbs to wilting, premature leaf drop or vine die back. During the heat of summer in the southern United States, it's best to irrigate the plant to keep it looking its best. As long as the garden soil is well-drained, there is little concern for suffocating roots from over-watering.

Other Insight

• Few diseases and insect pests bother lilac vine. However, in hot, dry sandy soils, nematodes exist in greater numbers and will attack roots, damaging them and preventing water uptake to sustain the leaves and stems. This is seen as random wilting while other plants nearby seem to be fine. Also in hot weather, when humidity and winds are low, spidermites can proliferate in webbed nests on the undersides of leaves. These tiny red-bodied arachnids bite into stems and leaves, sucking juices from tissues that can cause wilting or widespread yellow and dying of foliage.