Rhododendrons For Zone 4 Gardens - Types Of Cold Hardy Rhododendrons

Cold Hardy Rhododendrons

Northern Hi-Lights – White blooms.
Golden Lights – Golden flowers.
Orchid Lights – White flowers.
Spicy Lights – Salmon blooms.
White Lights – White flowers.
Rosy Lights – Deeply pink blooms.
Pink Lights – Pale, soft pink flowers.

What is the hardiest rhododendron?

Slightly fragrant and exceptionally cold hardy, Rhododendron 'Karens' is a very eye-catching, dense and compact, semi-evergreen Azalea.
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Hardiness	5 - 9
Season of Interest	Spring (Mid,Late) Fall Winter
Height	3' - 5' (90cm - 150cm)
Spread	3' - 5' (90cm - 150cm)

How cold can rhododendrons take?

Certain rhododendrons and deciduous azaleas can survive temperatures as low as -35°F (-37°C). It is normal for some rhododendrons to exhibit leaf droop and curl at around 32°F (0°C).; the lower the temperature the tighter the curl. Leaf movement occurs rapidly and it is reversible as temperature warms.

Where is the best place to plant a rhododendron?

Unlike many blooming plants, rhododendron does not like full morning sun in winter and does best when planted in dappled shade on the north side of a building. Growing rhododendrons are happiest in a location protected from the wind and not under eves of a building.

Do rhododendron keep leaves in winter?

Bursting with vibrant blooms in the spring and retaining their leaves through the colder months, rhododendrons are the perfect "evergreen" for your winter landscape.

Are rhododendrons OK in shade?

Choose a site with dappled shade in sheltered conditions. Avoid deep shade beneath other trees. Most rhododendrons will tolerate a more open site if sheltered from cold, drying winds. Dwarf alpine species will tolerate full sun provided the soil does not dry out.

Do rhododendrons like sun or shade?

Most large-leafed varieties require dappled shade; avoid deep shade or full sun. A sunny spot that receives a few hours of shade is perfect. See regional guidelines below. Soil should be well-drained, humus-rich, moist, and acidic (pH 4.5–6).

Should you cover rhododendrons?

PJM type rhododendrons in most years will not require extra winter care. For the other years protection from the winter sun and wind is the most important measure you can take. This is best accomplished by wrapping the plant in burlap, or enclosing it in a burlap tent.

Will frost hurt rhododendrons?

Camellias, rhododendrons and other broadleaf evergreens will likely have fewer flower blooms this coming spring if the developing buds freeze. To get an idea of the extent of freezing damage, cut forming buds open. If they are green, the flower is still okay. If they are brown or black, the flower bud has been killed.

What's a good fertilizer for rhododendrons?

At planting time, use 10-10-6 fertilizer before you water the plant in. In early spring, the rhododendron buds swell. At this time, apply a complete 10-8-6 fertilizer. Apply another light dose of this fertilizer when the leaves emerge.

What time of year should you plant rhododendrons?

In mild climates rhododendrons and azaleas can be planted almost any time of the year with reasonable success. In colder areas, early spring planting is recommended, with early fall planting being a second choice.

Are coffee grounds good for rhododendrons?

Fresh Coffee Grounds for Acid-Loving Plants

Your acid-loving plants like hydrangeas, rhododendrons, azaleas, lily of the valley, blueberries, carrots, and radishes can get a boost from fresh grounds. ... Fresh coffee grounds still have most of their caffeine content as well as the acid.

Why do rhododendrons turn yellow?

If your soil is alkaline, you've found one reason for rhododendron leaves turning yellow: a mineral deficiency causing chlorosis. These shrubs take up too much calcium and not enough iron in alkaline soils. Chlorosis is very likely when the yellowing is mostly between the veins of new leaves.

How do I protect my rhododendrons for the winter?

Avoid exposed southern or western sites where winter sun and wind will cause the most damage. Other important measures include mulching or using physical barriers such as burlap to block the wind. Mulching rhododendrons, especially those that have been newly planted, insulates the soil and protects the plant's roots.

Do rhododendrons have deep roots?

Rhododendrons do not have thick, deep taproots; their roots are fine and grow very superficially. Therefore, they may need reliable moisture to avoid damage from drying out. That said, once established, most rhodies are relatively drought tolerant (and slow growing).

Why do the leaves curl on my rhododendron?

Leaf curl on Rhododendrons is most frequently seen when the plants are under stress from drought, stem injury or cold temperatures. ... If heavy snows break branches, so that they can no longer take water up to the leaves, this too causes foliage to curl and die.

Are rhododendrons poisonous to dogs?

All parts of the rhododendron plant are toxic for dogs. Symptoms include gastrointestinal upset followed by weakness, paralysis, and abnormal heart rhythms.

Can you cut rhododendrons to the ground?

In severe cases, you can sometimes cut your rhododendron to within 6 inches of the ground. Rejuvenation pruning is best used to restore shrubs that have become leggy, overgrown, or otherwise unattractive. ... It's best to perform this type of pruning in winter, while the plant is dormant.

When should rhododendrons be pruned?

According to most professional landscapers, the ideal time for pruning rhododendrons is late winter, while the plant is dormant. However, any time between the first frost in fall and the last frost in spring (while the sap is low) will work.

Are rhododendrons difficult to grow?

Rhododendrons need moist, acid, loose, well-drained soil that contains a good bit of organic matter. This is why they're hard to grow here. Most Southerners have either acid, clay soil or alkaline, clay soil. Rhododendrons hate both, because clay drains slowly and roots rot.

Do rhododendrons need a lot of water?

Rhododendrons are shallow-rooted plants that require water twice per week during the first growing season. ... Though rhododendrons need consistent moisture, they do not do well when sitting in wet soils, so always allow the soil to dry between waterings.

Do rhododendrons grow well in pots?

Rhododendrons grow best in acidic soil, says Stephen. They like dappled shade or even full shade. . ... But they do well in pots, so if your soil isn't right for them, you could grow them in a pot. Either wedge it in a border or put it on a terrace.