Rhododendrons are popular among gardeners with their evergreen shrubbery and early blooms.
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Planting, Growing, and Pruning Rhododendrons and Azaleas
Planting
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鈥6).
Azaleas and rhododendrons have shallow root systems and need moist soil and mulch to keep them from drying out. Amend planting areas with compost, peat moss, or a substitute, only if your soil is poor. Learn more about soil amendments and preparing soil for planting.
鈫 Not sure which hardiness zone you鈥檙e in? See the USDA map.
Planting in Cold or Temperate Regions (Zones 3 to 6)
- Plant in full sun to increase flowers and avoid mildew problems. Shrubs need a minimum of 6 hours of full sun daily.
- Plant on the sheltered side of a windbreak. If subjected to cold, dry winds, their leaves and buds dry out and die, especially during winter winds.
Planting in Warm or Hot Regions (Zones 7 to 11)
- Plant in a site that receives afternoon shade, especially in hot areas. In tropical zones, azaleas will bloom in full shade.
How to Plant Rhododendron & Azaleas
- Plant in spring or early fall.
- Space plants 2 to 6 feet apart, depending on their estimated mature size. Dig a hole as deep as the root ball and about twice as wide.
- Set new plants so that their top roots are at soil level or slightly below. If you plant them any deeper, the roots and trunks may rot.
- Fill the hole half full with soil, then water it well to settle the soil before filling it with the remainder of the soil.
Growing
How to Care for Rhododendron & Azaleas
- Mulch plants every spring with 2 to 5 inches of pine bark chips or pine needles to protect shallow roots and retain soil moisture. A lack of water reduces flower bud formation. Read more about using mulch.
- Tip: A common mistake is to create a so-called 鈥渕ulch volcano,鈥 where mulch is piled heavily around the trunk of the shrub. In fact, this can keep the trunk too wet and encourage rot. Always leave a few inches around the trunk free of mulch.
- See our guide to using mulch.
- Fertilize azaleas and rhododendrons sparingly and only when flower buds swell in the early spring, even if they are fall bloomers. Heavy applications of fertilizer will burn the plants鈥 roots.
- Water plants during the summer if rainfall is less than 1 inch per week.
- After flowering, deadhead where practical, to promote vegetative growth rather than seed production. Remove dead flowers from rhododendrons carefully; next year鈥檚 buds are just under the old heads and will start to develop shortly after flowering.
- Azaleas and rhododendrons may be transplanted at any time during the growing season, but they transplant most successfully during fall or early spring when they are dormant and temperatures are cool.
Winter Care for Rhododendrons
Rhododendrons are shallow-rooted plants; in cold regions, apply several inches of organic mulch around the base. In regions with severe winters, consider wrapping evergreen rhododendrons with burlap in the fall. Cold, dry winds will cause too much moisture evaporation from the leaves, which will wither and die. To help them recover from cold snaps, deeply water rhododendrons if there are warmer days. In the spring, prune out any dead or damaged branches and leaves.
Pruning Rhododendron & Azaleas
- In general, do not prune spring-flowering shrubs such as azaleas and rhododendrons. If you need to reduce height, prune after flowering in the spring.
- Otherwise, just remove dead, damaged, or diseased branches at any time of year.
- On young and old plants, simply snap off spent flower stalks by bending them over until they break away from their stems. Be careful not to damage growth buds at the base of each flower stalk.
Catherine Boeckmann
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Although rhododendrons like moist soil, they do not like it to be waterlogged, preferring well-drained soil. It sounds like even though the soil in the area you describe isn’t soggy at all times of the year, it would not be ideal for the rhododendrons, which might suffer. If you could find a drier place to plant them, they might be happier. Or if there is not one available, and you still would like to try planting these shrubs, then you might try planting them in a raised bed, to keep the soil drier (although in dry or hot weather, you’d need to water more often).
Can u start a tree from the bud
When I purchased my house, I was excited to see that there were two rhododendrons in the front flower beds; however, these plants are starting to take over the whole flower beds--most of my neighbors have fairly compact rhododendron plants, but mine are sprawling and definitely need to be cut back. I love them and don't want to do anything to hurt them, so I just wanted to see if there was any advice on the best way to trim them back without killing them. They haven't started blooming yet this year (winter's been hanging on in Ohio for a while and spring is just arriving), so I wasn't sure if I should wait until after they bloom or not. Thank you!
planted in fall of 2016.. bloomed in spring of 2017. ...after that and through the summer the plant started dying..tried to prune in fall..it now looks more dead than alive and has 2 buds..can you tell me what happened??
Do a soil test. It is highly likely that the plant is suffering in a too alkaline soil. It likes acid (see above) and here: /content/soil-ph-levels
You can do a soil test with a kit from a local nursery/home store (that sells gardening things); it’s quick and easy, and you can see if/how the pH may be 鈥渙ff.鈥 And/or, you can contact your local cooperative extension service and do a more thorough one for a bit more time and money (but not a lot): /content/cooperative-extension-services
On the pH link page you will find guidance for changing the pH. While you’re there, notice the plants and what they like: rhodos and azaleas like acidic soil while lilac likes sweeter soil. Look around your property (if this applies) and see what else in this list is thriving and, possibly, what is fading and notice their pH number.
My husband planted Azalea's last year in the spring. So far this year there have been no signs of blooms yet and some of the leaves are brown but there are also plenty green leaves as well. Not sure what could be wrong. What should we do? Thank you!!
The first season, it’s not unusual to find that a new azalea isn’t bloomoing. They are busy setting up a root system and getting established. But if the same thing happens next spring, that could be a problem. You should see some flowerbuds though. Also, if your azaleas bloom late, ONLY prune right after the flowers fade. Do not prune in ate summer, fall, or winter because you will remove the remove flowerbuds and keep them from blooming next spring. Care for them this summer and see what happens next spring.
It is Dec. 10th. I live in Conway, SC. I just purchased a Rhododendron/azalea from Loew's which looks healthy and has beautiful blooms on it. Someone in the store told me this is an "ideal" time to put this plant in the ground. I am hesitant. I wondered if (1) I should keep this potted plant outdoors during the day and bring it in at night (in the garage) as I have been; or (2) put the pot into the ground, cover around the plant with mulch and wait until Spring after the last frost to put it in the ground? I don't want to lose this one! PS someone told me if I keep the plant in the pot and keep it outdoors, it will die because the roots will get too cold. Thank you!!
The guidance on when to plant a rhododendron in South Carolina is fall, allowing the plant tome to acclimate and prepare for spring growth. The best thing might be what you are doing. Putting the pot into the ground鈥攁nd then pulling it out in a few months鈥攚ill only disrupt it twice. Once as it adjusts to the outdoors 24/7, and again when you lift it to make it start all over again without the pot. So plant it in the spring but be aware that as a shallow-rooted plant, it will need regular, generous watering鈥攂ut not be soggy鈥攁s the temps rise. Well draining soil and good mulch should keep it from drowning. Do not put it in a place that gets heavy, constant sun, especially from the south. It performs better under dappled shade. Get the soil right; see above. This is our recommendation. You might also inquire of the vendor from whom you bought it. And ask if they will replace it if it fails within the year. Some do. We hope this helps.
We had a very warm fall in north Georgia, and my huge rhododendron was starting to open it's spring buds. It was in partial flowering when we got hit by this snow storm and the entire top is buried. The half open blooms have shriveled up. Should I remove the half open blooms and hope new ones will form in spring? Or will I have a flowerless spring this year?
