The leaves of this fast-growing hardy shrub also feature attractive fall foliage, becoming tinged with deep red. This color show is as elegant and thrilling as it is reliable and looks great in a variety of landscape design styles. The flowers also look very nice in the vase as cut flowers, and can be dried for long-lasting decor. Wait until they start to turn blush pink before cutting them for drying. Plant Limelight hydrangea in the early spring or fall. Like all hydrangeas, the plant is toxic to humans, and toxic to pets. Limelight hydrangeas make a good landscape specimen plant but they do need room to spread. The shrub does not like to compete with other plants at its base so it’s best to avoid planting aggressive ground cover plants around them (like vinca or pachysandra). Give them a good natural mulch like shredded pine bark.
Light
The ideal amount of sunlight depends on your climate. In warm climates, it is best to choose a planting location with partial sun in the morning and not afternoon, as hot afternoon sun in the summer can cause the blooms to dry out. If you live in a colder zone, you can plant your hydrangea in full sun, but avoid a windy spot.
Soil
Hydrangeas in general prefer a rich, well-drained soil. For paniculata hydrangeas, a slightly acidic with a pH between 6.1-7.0 works well. Unlike other hydrangea types, the soil pH does not affect Limelight’s bloom color. If the shallow roots become exposed over time, add more soil and compost to keep them protected.
Water
Hydrangeas have moderate watering needs once they are established. They do best in evenly moist soil. In a dry spell, give your hydrangea a good deep watering once or twice a week as needed to mimic rainfall.
Temperature and Humidity
This is a very hardy variety of hydrangea that can withstand winters down to USDA zone 3. However it’s best to plant it where it won’t be vulnerable to damage from high winds. Hydrangeas don’t require any special humidity conditions. A muggy hot summer day may cause blooms to droop a bit.
Fertilizer
Hydrangeas benefit from light fertilization. Apply a granular flower food fertilizer in the spring, and again in late summer. For the amount to use, follow the product label instructions. Alternatively, some composted manure as a top dressing in autumn is also a good way to feed hydrangeas and keep roots healthy.
Types of Limelight Hydrangea
In addition to original Limelight hydrangea, two other cultivars have been developed:
‘Limelight Prime’, a smaller variety that only reaches 4 to 6 feet in height.‘Little Lime’, the smallest variety with a compact, mature height of 4 feet.
Pruning
Like all panicle hydrangeas, limelight hydrangea blooms on new wood (growth from the current year) so any pruning should be done in the late winter or early spring before new growth starts. Remove any dead wood and broken branches and cut down all the healthy stems by about one-third.
Propagating
Limelight hydrangea is a registered trademark and propagating it by cuttings or seeds is prohibited.
Potting and Repotting
The smaller varieties of Limelight hydrangea are suitable for container growing. A terracotta pot is ideal because it lets excess moisture evaporate and the soil stays cooler than in plastic. The material is also heavy enough so the plant does not topple over easily. Choose a container that is one or two sizes larger than the current pot, with a wide, flat base and large drainage holes. Fill the container with loose, well-draining potting mix. Roots growing out of the drainage holes will indicate when the hydrangea needs repotting to a larger container.
Overwintering
Limelight hydrangeas are hardy plants that do not need winter protection when planted in garden soil although a layer of mulch around the base insulates the roots against the cold. The roots of container-grown Limelight hydrangeas, on the other hand, are highly susceptible to frost damage and need protection. Either place the container in a larger pot or box and fill the space with mulch or sand for insulation, like a silo, or wrap the sides of the container with bubble wrap or burlap and an additional layer of plastic wrap.
Common Pests & Plants Diseases
Generally, Limelight hydrangea is a trouble-free shrub but it can get bud blight, rust, leaf spot, powdery mildew, and bacterial wilt. These fungal diseases are more likely in humid weather and when there is lack of air circulation. The shrub might get aphids and mites but they don’t affect the overall plant health.
How to Get Limelight Hydrangea to Bloom
The two main reasons why your Limelight hydrangea is not blooming are lack of sunlight and removal of the flower buds. Shrubs that do not receive sufficient sun will bloom poorly; sometimes it helps to cut back other trees or shrubs nearby to improve the light situation. As for pruning, if it’s done too late in the season and the flower buds have already formed, the chance of accidentally removing them is higher, so make sure to prune your hydrangea before the new growth starts.
