How to Grow Nova Zembla Rhododendron Like a Pro

Nova Zembla Rhododendron is an evergreen shrub distinguished by its leathery, green foliage and bright red trumpet-like flowers in the spring. It’s a hybrid cultivar introduced in the early 1900s by crossing Rhododendron 'Parsons Grandiflorum' with a hardy red rhododendron hybrid.

Nova Zembla Rhododendron has a reputation for hardiness and grows well even in cold climates. It does best with full to partial sunlight and needs rich, moist soil that has plenty of drainage. All parts of the plant are toxic to humans, as well as cats, dogs, and other animals.

Nova Zembla Rhododendron Care

These are the main care requirements for growing Nova Zembla rhododendron:

• Plant in rich, moist soil with plenty of drainage.

• Choose a location that receives partial to full sunlight.

• Water deeply as needed to maintain moist (but not soggy) soil.

• Feed with a well-balanced fertilizer if soil conditions are poor.

Light

While most rhododendrons can’t tolerate full sun, nova zembla rhododendron is the exception. Plant this shrub in a location that receives partial shade or full sun.

In very warm weather climates, you may need to choose a spot that has morning sun or dappled shade to avoid burning the foliage during periods of intense afternoon sun.

Soil

To support its prolific blooming activity and green foliage, nova zembla rhododendron needs nutrient-rich soil that has plenty of drainage to avoid waterlogged roots. It does best with acidic soil.

Water

Nova Zembla rhododendron should be watered regularly to ensure that the roots stay moist. Water deeply once per week or as needed but be careful not to oversaturate the soil. A layer of mulch can help the soil to retain moisture in between waterings.

Temperature and Humidity

This rhododendron cultivar is notable for its ability to withstand cold conditions. It can survive temperatures well below freezing; it’s suitable for growing in USDA hardiness zones 4 to 8. It also does fine in moderate to warm conditions, adding to the versatility of this plant in various locations.

Fertilizer

If the soil is nutrient-rich, nova zembla rhododendron may not need any additional fertilizer. But in less optimal soil conditions, you can apply a well-balanced fertilizer like 10-10-10 to support foliage and flower production.

If you are growing Nova Zembla rhododendrons in a cold climate, take note that it’s recommended that you avoid fertilizing the shrub from the end of June onward to avoid promoting late-season growth of tender foliage that might be damaged at the onset of cold temperatures.

Propagating Nova Zembla Rhododendron

Since Nova Zembla rhododendron is a cultivar it can’t be grown from seed because the resulting plant may not have all of the attributes of the parent plant. Propagation by cuttings is usually the simplest way to create a new shrub and it’s best done in the fall. Here’s how to do it:

1. Gather a pair of sharp pruning shears or scissors, a plastic bag, sterile damp potting mix (for example, a mixture of 60% milled sphagnum peat moss and 40% perlite), small pots or containers, and rooting hormone.

2. Take a few softwood cuttings below a leaf node. Each cutting should be 4 to 6 inches long with at least one set of leaves (but no flower buds). If there are more than four leaves, remove the extras.

3. Fill the containers with the damp potting mix. Then, dip the cut end into rooting hormone (tapping off any excess) and insert the cutting into the potting mix to a depth of about 2 inches. You can plant more than one cutting in each container.

4. Place the cuttings in a warm location with bright, indirect light and keep moist (but not soggy). Roots should develop in three or four months.

How to Get Nova Zembla Rhododendron to Bloom

Nova zembla rhododendrons are prized for their yearly display of scarlet-colored blooms. Like other species of Rhododendrons, the long-lasting blooms emerge in the spring and may peak in May or June.

Bloom Months

Nova zembla rhododendron blooms in the spring. May and June are the most active bloom months, depending on climate and planting location.

What Do Nova Zembla Rhododendron Flowers Look and Smell Like?

The flowers of this shrub are a bright red color, with a trumpet-like shape. The throat of the flower has spotty deep maroon shading.

While some rhododendrons have a notable, appealing fragrance, this cultivar doesn’t stand out on the merit of its scent. It has a very light, sweet smell that attracts pollinators, like hummingbirds and bees.

Deadheading Nova Zembla Rhododendron Flowers

You can remove spent blossoms from this shrub to keep its appearance tidy and to prevent self-seeding. Usually, it’s best to wait until the cluster has faded and remove the whole cluster at once by snapping off the stem that supports the cluster.

Common Problems With Nova Zembla Rhododendron

Nova zembla rhododendron is considered an iron-clad variety, meaning that it grows exceptionally well in cold conditions and can tolerate full sun better than some other types of rhododendrons.

Still, there are a few issues that can affect the vitality of this shrub; yellowing leaves is one of the most common symptoms to present itself.

Leaves Turning Yellow

If you notice that the leaves are turning yellow, it can be an indicator of a few different problems. The soil may be too alkaline; test the soil pH and amend as necessary to improve acidity. Overwatering may also cause the leaves to yellow as root rot sets in.

Check the health of the plant’s root ball and look for signs of rot, like slimy, pale roots with an odor. In addition, rhododendrons have a shallow root system. If you plant the shrub too deeply, it can also start to cause yellow leaves.

In the case of overwatering or a root system that is buried too deep, remove the shrub from the ground and amend the soil to improve drainage before replanting to an appropriate depth—just below the soil’s surface.

Frequently Asked Questions

How big does a Nova Zembla rhododendron get?

This type of large leaf rhododendron will grow to a height between 5 and 8 feet, with a spread of 5 to 6 feet. 

Is Nova Zembla rhododendron toxic to pets?

According to the ASPCA, the rhododendron plant is toxic to pets, including cats and dogs so you should not plant Nova Zembla rhododendron in a location where it’s accessible to your pet, especially while unsupervised.

Can Nova Zembla rhododendron grow in full shade?

Living up to its hardy reputation, Nova Zembla rhododendron is considered shade-tolerant but the location should still receive indirect light to prevent legginess and severely compromised bud and blossom production. A partial shade location is preferred.

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Read the original article on The Spruce.