Rhododendron

There’s been at least two or three rhododendron bushes in every place I’ve ever lived. I used to think it was a shrub that once planted, you just let it go and grow. When I moved to Bradford, I learned that with a little care, rhodies can be even more beautiful.

This past week I had a couple sections of stockade fence installed and decided to get new rhodies to go in front to pretty up the blank wall. (Later I will add my flair of painting – purple, of course! – along with some other decorating.)

Rhododendrons (rhodies) are a familiar spring blooming shrub that usually stands out because, not only the size of the plant itself, but for the large clusters of showy flowers. Rhodies belong to the genus of rhododendron and are the largest genus in the Ericaceae family. There are over 1,000 different species in the genus. The Ericaceae family also includes azaleas, heather, cranberries, blueberries, mountain laurel and more. Rhododendron is from the Greek and means rose tree.

All azaleas are in the rhododendron family but not all rhodies are azaleas. It depends on the subgenus and types of leaves. The leaves for the smaller azalea are usually pointed and narrow; the leaves of the rhododendron are generally large, leathery and paddle-shaped, although that can depend on the particular species/subspecies.

Note: Rhododendron are toxic to humans and pets. Do not eat any part of the plant! There is a lot of talk about the toxicity to bees and what is called “mad honey.” The websites I checked had some pros and cons. From what I can tell, the bottom line is rhodies attract bees, but as long as there are many other flowering plants and trees in your yard, there is no worry.

Rhododendrons can be evergreen or deciduous. The blossoms are usually tubular, funnel or bell-shaped, and often fragrant. Individual blossoms form in a ball-shaped truss. The flowers come in colors of white, red, pink, yellow, blue, purple, magenta, orange and various shades thereof.  The shrubs come in a variety of shapes and sizes and leaf shapes vary in size, shape and texture.

Rhodies prefer environments where it is neither too hot nor too cold (Zones 5 to 8) and need a certain amount of chilling to develop strong flower buds. Though most flower in the spring, there are also summer-blooming varieties that add color and charm to any garden.

Planting

Most large-leaved varieties require dappled shade; avoid deep shade or full sun. They do not like full morning sun in winter. Choose a sunny spot that receives a few hours of shade is perfect. Soil should be well-drained, humus-rich, moist, and acidic (pH 4.5-6). Soggy and waterlogged roots are the main causes of failure. The north side of a building not under the eaves is best, protected from the wind. If you’re planting in a more open area, make sure to choose a more tolerant species.

If you can prepare the soil in the fall for planting in the spring. (Of course, I never plan that far ahead, ha ha.) Amend the planting area with compost, peat moss or a substitute. Oak leaves are good, too. If the shrub has a root ball, soak before planting by placing it in a tub of water until air bubbles disappear.

Plant the shrub in loamy fertile soil so the top roots are at soil level or slightly below. If you plant them any deeper, the roots may rot. If the plant was in a pot, plant it so the crown is the same level as it was in the pot.

Regular rhody care

Rhodies have a shallow root system and need consistent moist soil and at least two inches of mulch to keep them from drying out.

Tip: When the leaves curl and twist, water immediately. Do not allow the stress of wilting. Shade loving annuals, such as the annual impatiens, may be planted near the rhody and will also indicate when water is needed.

Fertilize in the fall with an acid loving material. Pine needles make a good mulch. Wrap rhododendrons with burlap in the fall if winters are severe. Winter burn results from frozen soil, freezing winds and cold winter sun.

Pruning

Snap off spent flower stalks by bending them over until they break away from their stems. Remove dead flowers carefully because next year’s buds are just under the old heads. Be careful not to damage growth buds at the base of each flower stalk. Deadheading, where practical, promotes vegetative growth rather than seed production.

Heavy pruning will help rejuvenate a plant but may take a couple years before it will bloom again. I personally experienced this. The first year I lived in Bradford some of the rhodie leaves turned brown during the winter. My brother, who did landscaping for years, said it was winter burn. He suggested early in the spring pruning back the parts/branches that were damaged. It would not harm the plant to cut it back to within a few inches from the soil.

I was hesitant but trusted him. I trimmed up some of the shrubs and cut the most damaged one almost entirely to the ground. By mid-summer, there was signs of new life and yes, it took a couple years to bloom again. As I had never seen this one in bloom before, I was pleased to see a beautiful shade of cream (not like the standard purple-pink color of the most the others).

Also, one of the bushes in a closed-in corner between the sunroom and garage was so well-protected that it grew huge; covering almost the entire corner width-wise and up over the roof. Again, Don said to cut it right back, not to the ground, just to give it better shape and allow more airflow through the shrubbery. Soon it began showing new life. How exciting!

This week someone saw one of my Facebook photos of my newest rhododendron (rhodies). He asked how to get rhododendrons to bloom.

Some people are lucky enough to just have the right spot for their rhodies to blossom well. For others, their rhodies may take a little care, especially with the hybrid varieties.

Know which type of rhodie you have. Some require more sun while others prefer shadier areas (but not total shade). Realize too, as the trees around your yard grow and change, that could change the amount of sunlight your garden gets.

So here are a few tips:

If the shrub is new, was it planted too deep? Rhodies have shallow roots. Only plant the new shrub as deep as the root ball. Tip: A straight handled tool placed across the ground of the newly planted shrub should lie level with the area around it.  

New plants need to get established and may take a couple of years to bloom.

Adding 2-5 inches of mulch will help keep in moisture in the soil. Mulch or pine needles permit needed air but mounding the plant roots and stem with soil may prevent blooming.

In the spring, fertilize lightly when the buds swell. Cut back on fertilizing and watering in late summer. Coffee grounds worked into compost or into the soil will boost the acidity level required by rhodies.

If you prune off the spent blossoms, do so right after they fade. Next year’s buds begin forming quickly and waiting too long to deadhead will remove next year’s growth. Try to remove spent blooms before it goes to seed by holding the stem and carefully snapping off the flower head without damaging the new buds.

After the blooming period, check the plant for health and cut away any parts that are dead. A rhodie pruned back a lot, may take more than one season for it to blossom again. In this case, be patient.

Some rhodies bloom a lot, some may not bloom every year.