How and when do I prune oleanders?
- Oleander Oleander Photo: BethinAZ, Http://flickr.com/creativecommons/by-2.0/
Photo: BethinAZ, Http://flickr.com/creativecommons/by-2.0/ Image 1 of / 1
Image 1 of 1 Oleander Oleander Photo: BethinAZ, Http://flickr.com/creativecommons/by-2.0/ How and when do I prune oleanders? 1 / 1 Back to Gallery
Oleanders, which are flowering shrubs, have many landscape uses since plants vary from dwarfs under 4 feet tall to intermediates in the 4- to 6-foot range to those that reach 6 to 25 feet if unpruned.
Ideally, the oleander (Nerium oleander) is pruned after blooming. All types — spring or free-bloomers – should be pruned by the end of August or early September to give any new growth sufficient time to harden off before winter.
Oleanders have a globular shape, and in this billowy, full form a single shrub makes a handsome specimen; several make an evergreen hedge.
Little pruning is required to maintain this natural shape.
Broken, weak, crossing or dead branches should be removed. An unwanted stem may be removed at ground level or where it joins an older stem.
A rule of thumb is not to prune more than a third of the existing foliage and to carefully prune stems so that removal is evenly distributed for a balanced look.
Oleanders should be cut back just above the leaf nodes. This is the section where three leaves come out of the branch. By cutting it here, you will be forcing new branching at each of the leaf nodes (joints). Three new branches will grow from the section that once had three leaves. If you allow these new branches to grow a little and then prune them also (at the leaf nodes), you will force new branching to occur at these points. By doing this, you will increase the branch threefold.
This is how you get round, bushy plants.
Oleanders can be shaped into conical, multistem bouquets. This form is similar to the natural multistem, globose shape of the oleander, but is pruned to have a more narrow base. Oleanders also may be pruned into multistem forms or single-trunk small trees, but those require more pruning maintenance.
The oleander is a relative of the periwinkle and is available in red, pink, coral, yellow and white. The blooms may be shaped like stars, pinwheels or cups and may be singles or doubles.
Some varieties are spring bloomers, while others flower freely through the summer. Some have a vanilla fragrance.
All have evergreen, willowlike foliage.
A newly planted oleander will need some care, but once established, maintenance is minimal. A good candidate for a xeriscape, the oleander accepts alkaline, sandy soils found on Bolivar and Galveston as well as heavier Houston soils. The oleander tolerates soils with salt, too.
Plant oleanders in a well-draining soil enriched with some compost. Full sun is best for a profusion of blooms; you’ll find fewer blooms in partial shade. Varieties vary in cold-tolerance, but many are root-hardy.
Galveston gardeners say oleanders require little or no fertilizer. Plants with light green foliage and / or few flowers will benefit from an application of a balanced fertilizer in early spring and another in early fall. Water well after fertilizing.
Ole! Ole! Oleander!
“Oh, that won’t grow here.” How many times have aspiring gardeners had their hopes dashed by such a blanket statement? The fact is just because you don’t see something growing in your neighborhood doesn’t mean it won’t. Oleander (Nerium oleander) is a good example.
Native to the Mediterranean region, this shrub has so much going for it. It’s evergreen. It’s easy. It’s tough. It offers weeks of beautiful single or double flowers in a huge range of colors, including red, pink, peach, yellow, and white. The only thing that holds it back is tenderness to cold.
Because many people see oleander growing at the beach, they think it won’t take frost. They are wrong. More than 25 years ago, I bought a small pink oleander at a garden center on Pawley’s Island, South Carolina while on a family vacation. I took it home to Maryland. When I moved to Alabama, that oleander came with me. It’s blooming this very day (see photo below). And I’ve learned how much cold oleanders can really take.
Twenty degrees. That’s how cold it can get without causing any damage to flower buds or foliage. At 10 degrees, flower buds die and leaves get burned. At 0 degrees, the plant will probably die to the ground and then regrow. Because mine grows in a big pot, I take it inside the garage when night temps drop into the teens. But especially hardy selections, such as ‘Hardy Pink’ and ‘Hardy Red,’ do bend the barriers. I’ve seen an established, 10-foot tall, pink oleander in full bloom growing in front of a house in Moundville, Alabama. I know it’s been there for years.
Growing conditions. Other than winter cold, almost nothing bothers oleander. Just about any well-drained soil will do — acid or alkaline. Once established, it’s very drought-tolerant. It also withstands wind and salt spray, which is why it’s a favorite for beach planting. It needs little fertilizer. Give it full sun. Very few pests assault it, except for oleander caterpillars (see below).
Pests. Moths lay eggs on the undersides of the leaves. The eggs hatch into voracious bright orange caterpillars with tufts of black hairs. Severe infestations can defoliate a plant. To prevent this, spray your plant according to label directions with Bt (Bacillus thuringiensis), a bacterium that is harmless to people, pets, and most insects, but lethal to caterpillars.
Pruning. Oleanders can grow 10-20 feet tall if you let them, so here are some basic pruning guidelines. Prune these shrubs immediately after their flowers fade. This will encourage new, fresh growth and you may get more flowers. Older oleanders may get woody and bare at the bottom. Rejuvenate them by cutting off 1/3 of the oldest trunks at ground level in spring over a three-year period. Don’t want to prune? Buy a dwarf selections, such as ‘Turner’s Carnival.’ It grows only about 4 feet tall.
Where to buy. You’ll often find oleanders for sale in local garden centers and nurseries. Top Tropicals is a good mail-order source.
Isn’t oleander poisonous? Why, yes, the sap is. Despite this, hardly anyone gets poisoned, because the leathery leaves and stems are thoroughly unappetizing, unless you’re an oleander caterpillar. The Grump did hear of Boy Scouts getting poisoned by toasting marshmallows over a campfire using oleander sticks for skewers. My expert advice? Don’t do this.
Thanks to kellyv, mccheek, and cjewell for photos.
Rejuvenating Overgrown Oleanders: Tips For Pruning An Overgrown Oleander
Oleanders (Nerium oleander) accept severe pruning. If you move into a house with an unruly, overgrown oleander bush in the back yard, don’t despair. Rejuvenating overgrown oleanders is largely a matter of pruning and patience. Read on for information about rejuvenation pruning of oleander and when to prune oleanders to rejuvenate them.
Pruning an Overgrown Oleander
The good news is that you can do rejuvenation pruning of oleanders and get old, overgrown plants back into shape. You’ll have to evaluate the health of the oleander shrub and determine if it can withstand drastic pruning all at one time.
The problem with one severe pruning is that it can induce excess foliage growth and encourage basal sprouting. If the plant is in fragile health, its vigor can be reduced
and a very weak plant may even die.
When you consider pruning an overgrown oleander severely, you may be better off to do it little by little, over a number of years. When you are rejuvenating overgrown oleanders over three years, you do about one-third of the requisite thinning every year.
How to Trim Overgrown Oleander Shrubs
Generally, you’ll want to keep a shrub’s natural shape when you start pruning, even when you are pruning an overgrown oleander. The oleander’s natural shape – a clumping-type shape – is almost always more attractive in oleander hedges and screens.
Here are tips for how to trim overgrown oleander shrubs over three years:
- The first year, snip one-third of all mature stems to the ground.
- The second year you are rejuvenating overgrown oleanders, trim half of the remaining mature stems to the ground, and shorten the long shoots resulting from the prior year’s growth.
- The third year, trim back the remaining older stems to a few inches, and continue heading back new shoots.
When to Prune Oleanders
Generally, the time to prune most spring flowering shrubs is late summer or autumn, or just after blooming. This gives the plants a chance to develop the new growth on which next season’s blossoms will grow.
However, summer flowering shrubs, like oleander, should be pruned in late winter or spring. Don’t prune in fall or mid-winter since this encourages frost-sensitive new growth.