Rhododendron 'Nova Zembla'
Rhododendron 'Nova Zembla' · Ericaceae Popular
One of the hardiest and most heat-tolerant large rhododendrons, with trusses of true red flowers in late spring over bold, dark evergreen leaves.
- Size
- 6½ ft tall, 6½ ft wide
- Zones
- 4 to 8
- Light
- Part sun to part shade
- Flowers
- Late May to mid June
- Pets
- Toxic (severe)
- Job in a bed
- Anchor
A bed built around rhododendron 'Nova Zembla'
The planner designed this bed around rhododendron 'Nova Zembla' when this page was made: a 16 × 8 ft (4.9 × 2.4 m) English border in zone 6, part sun. It chose the other plants from the 708 that suit those conditions, and says below why rhododendron 'Nova Zembla' stands where it does.
The plants
- 1 Rhododendron 'Nova Zembla' × 1, red
- 2 Leadwort × 24, blue
- 3 Bloody cranesbill 'Max Frei' × 9, pink
- 4 White mugwort × 3, cream
- 5 Siberian iris 'Caesar's Brother' × 5, purple
- 6 Virginia bluebells × 8, blue
- 7 Easter lily × 4, white
- 8 Asiatic lily × 4, yellow
- 9 Camassia × 5, blue
Why this plant
- The only bold leaves here. The rest are medium and fine. A change of leaf keeps plants distinct when nothing is in flower.
- The bed's only structure. Shrubs and grasses keep their shape when the perennials die down, and it is the only one here.
- The only red.
Why here
- Anchors a back corner. At 6½ ft it is the tallest plant here, and the tallest close the ends of the bed, where they stand in front of nothing.
- A step in the back row. Next to Siberian iris 'Caesar's Brother' (3½ ft): no two neighbours there are the same height, so the back steps up and down like a skyline.
- One plant, alone. A shrub is seen as an object, and needs clear ground around it.
Why now
- In flower for four weeks. From late May to mid June.
- Part of the bed's peak. With bloody cranesbill 'Max Frei', Siberian iris 'Caesar's Brother' and camassia in late May: 4 kinds at once. No week has more.
- The only leaves in winter. From November to March it is what there is to look at.
Planned as an English border: 7 of the 8 groups (88%) are drifts, longer along the bed than they are deep. The bed is tied together by its repeats: three kinds come round again along it, among them leadwort and bloody cranesbill 'Max Frei'. The most in flower at one time is 4 kinds, in late May.
The planner's own design check: 10 Excellent, 6 Good, 1 Satisfactory.
Open this bed in the planner Change its size, the sun or the style, move plants about, or swap one for another.
Where rhododendron 'Nova Zembla' goes in a border
At 6½ ft it belongs at the back of a bed. In the planner's ten height classes it is very tall (5 to 6½ ft).
Its job: anchor. A shrub that gives the bed permanent structure. Planted singly, as soon as the front edge is laid; everything else is arranged around it.
An 'ironclad' hybrid that succeeds where fussier rhododendrons fail. The red is strong; keep it away from orange and magenta, and near white or dark green.
- Red flowers in part shade
- Evergreen screening
- Cold-climate gardens
What to plant with rhododendron 'Nova Zembla'
Plants recorded as good partners for it, and what each pairing does:
- Christmas fern: its dark green leaves are a setting for the flowers, before and after; medium leaves against its bold ones; low enough (20 in) to stand in front of it.
- Hosta: its green leaves are a setting for the flowers, before and after; spires rising out of its mound; low enough (18 in) to stand in front of it.
- Lady fern: its green leaves are a setting for the flowers, before and after; fine leaves against its bold ones; low enough (2½ ft) to stand in front of it.
Questions about rhododendron 'Nova Zembla'
Does rhododendron 'Nova Zembla' need sun or shade?
Rhododendron 'Nova Zembla' grows in part sun (4 to 6 hours of sun, including some afternoon sun) and part shade (2 to 4 hours of sun, mostly in the morning).
It wants soil that stays evenly moist, rich in organic matter, and a good soak in dry spells.
What zones does rhododendron 'Nova Zembla' grow in?
USDA zones 4 to 8. It is hardy to zone 4, which means it survives winter nights down to about −20 °F (−29 °C).
Above zone 8 it struggles: the zones measure winter cold, but a plant's top zone usually means the summers are too hot or the winters too mild for it to rest.
Gardening in Canada? Use the USDA zone for your town: Canada's own zone map uses different numbers.
When does rhododendron 'Nova Zembla' flower in my zone?
In zone 5 it flowers late May to mid June. As a spring flower it moves about a week for every zone: earlier where it is warmer, later where it is colder.
| Zone 4 | Late May to late June |
|---|---|
| Zone 5 | Late May to mid June |
| Zone 6 | Mid May to mid June |
| Zone 7 | Early May to early June |
| Zone 8 | Early May to early June |
Worked out from Hopkins' bioclimatic law: spring arrives about four days later for each degree of latitude north, and one zone is roughly two degrees. A warm spring or a cold one moves any garden two weeks either way.
How far apart should rhododendron 'Nova Zembla' be planted?
5 ft (150 cm) apart, from the middle of one plant to the middle of the next. That is a little closer than its full width of 6½ ft (200 cm), so a group knits into one patch.
It grows 6½ ft (200 cm) tall. Give it the full distance from anything taller, or it will lean out towards the light.
How many rhododendron 'Nova Zembla' plants do I need?
Usually one. At 5 ft (150 cm) across, it is a plant you place, not one you mass. For a hedge or screen, set them 5 ft apart: three plants for a 10 ft run.
In the bed above, the planner used one in one group.
Is rhododendron 'Nova Zembla' poisonous to dogs and cats?
Yes: severe toxicity to people, dogs, cats and horses. All parts, including the nectar, are highly poisonous if eaten and can affect the heart.
Rated from the ASPCA. Where references disagree, the more cautious rating is used.
Is there a pet-safe plant like rhododendron 'Nova Zembla'?
These come closest to doing what rhododendron 'Nova Zembla' does, and no toxicity is recorded for them:
- Siberian dogwood: the same job in a bed, the same size and the same flowering time; white, not red, medium leaves, not bold.
- Witherod viburnum 'Winterthur': the same job in a bed, the same size and the same flowering time; white, not red, medium leaves, not bold.
Matched the way the planner's Swap button matches plants: the same job in a bed, then size, then flowering time.
What flowers after rhododendron 'Nova Zembla'?
Rhododendron 'Nova Zembla' is over by mid June. These start as it finishes and carry the same spot on, so it never goes flat:
- Foxglove: from early June to mid July, 4 ft tall, to stand in front of it and cover its fading stems.
- Feather reed grass 'Karl Foerster': from late June to early October, 5 ft tall, to stand in front of it and cover its fading stems.
- Smooth hydrangea 'Incrediball': from late June to early September, 5 ft tall, to stand in front of it and cover its fading stems.
What does rhododendron 'Nova Zembla' look like in winter?
Rhododendron 'Nova Zembla' keeps its dark green leaves all winter, so it is one of the plants that hold a bed together from November to March, when the perennials have gone.
More Rhododendron
- Azalea 'Delaware Valley White' Rhododendron 'Delaware Valley White'
- Azalea 'Hino-Crimson' Rhododendron 'Hino-Crimson'
- Catawba rhododendron Rhododendron catawbiense
- Evergreen azalea Rhododendron (Kurume hybrids)
- Flame azalea Rhododendron calendulaceum
- Korean rhododendron 'Cornell Pink' Rhododendron mucronulatum 'Cornell Pink'
- Northern Lights azalea Rhododendron (Northern Lights Group)
- Pinxterbloom azalea Rhododendron periclymenoides
- Reblooming azalea Rhododendron (Encore Group)
- Rhododendron 'Cunningham's White' Rhododendron 'Cunningham's White'
- Rhododendron 'Olga Mezitt' Rhododendron 'Olga Mezitt'
- Rhododendron 'PJM' Rhododendron 'PJM'
- Rhododendron 'Purple Gem' Rhododendron 'Purple Gem'
- Rhododendron 'Roseum Elegans' Rhododendron 'Roseum Elegans'
- Rosebay rhododendron Rhododendron maximum
- Royal azalea Rhododendron schlippenbachii
- Swamp azalea Rhododendron viscosum
- Yak rhododendron Rhododendron yakushimanum
In these guides
Every fact on record
- Type
- Shrub
- Size
- 6½ ft (200 cm) tall, 6½ ft (200 cm) wide
- Plant
- 5 ft (150 cm) apart
- Height class
- Very tall (5 to 6½ ft)
- Place in the bed
- Back
- Flowers
- Late May to mid June; dense clusters; red
- Leaves
- Bold texture, evergreen; dark green
- Shape
- Rounded, clumping
- Hardy in
- USDA zones 4 to 8
- Light
- Part sun, part shade
- Soil
- Rich, evenly moist
- Water
- Moderate
- Feeding
- Light, in spring
- Family
- Ericaceae
Checked against ASPCA poison lists. Flowering times are for zone 5: later in colder zones, earlier in warmer ones. Toxicity and spread information is a general gardening guide, not veterinary or medical advice, and invasive status varies by region. If a person or pet eats a plant, contact poison control or a vet. Check your local invasive species list before planting anything with a spread warning.