Seeds from
a red Rhododendron are likely to flower pale lavender. Cuttings insure a
duplicate of the parent plant. How do you prune Rhododendrons and what
does pinching a Rhododendron mean? These are frequently asked
questions.
Pinching
is a low impact form of pruning that is very effective for creating
nice, tight full plants when you are growing small plants from seeds or
cuttings. Typically a Rhododendron forms a single new bud at the tip of
each branch. This new bud will develop into another new branch, another
bud will form and the process will continue. If left alone this will
produce a very lanky plant with a lot of space between the branches
forming a very unattractive plant.
So if you
are starting with a plant that is nothing more than a rooted cutting all
you have to do is pinch off this new growth bud as soon as it is about
3/8” long. Just grab it between your fingers and snap it completely off.
When you do this the plant usually responds by replacing that single bud
with two, three, or even four new buds in a cluster around the bud that
you pinched off. Each one of these buds will develop into branches and
eventually a single bud will appear at the tip of each of these
branches, and of course you should come along and pinch each one of
those off forcing the plant to produce multiple buds at the end of each
of these branches.
The more
often you pinch off these single buds, the more branches the plant will
form, making a nice, tight, full plant. This is especially helpful with
young plants such as rooted cuttings or young seedlings.
But what
about larger plants, how do I prune them? I prune mine with hedge
shears!!! I just have at it and trim them like I would a Taxus or a
Juniper, and guess what? The result is a very tight compact plant loaded
with beautiful flowers. My Rhododendrons are so tightly branched that
you can not see through them, and that is the result of vigorous pruning
with hedge shears. Sure you can use hand shears, and you’ll have a nicer
plant because of it, but I just use the hedge shears because that’s the
tool that I happen to have in my hand as I am going by.
Keeping
Rhododendrons and Azaleas healthy and happy is a simple as understanding
what they like. First of all they like to grow in a climate that suites
their tastes. Many varieties of both don’t like it in the north, and to
prove the point they will up and die as soon as extreme cold weather
hits. Buy plants that are known to be hardy in your area.
Here in
zone 5 (northern Ohio) the following Azaleas seem to do well. Hino
Crimson (red), Stewartstonia (red), Herbert (lavender), Cascade (white),
Delaware Valley (white), and Rosebud (pink). Hardy Rhododendrons include
Roseum Elegans (pinkish lavender), English Roseum (pinkish lavender),
Nova Zembla (red), Lee’s Dark Purple, Chinoides (white), and
Cunningham’s (white).
How should
you fertilize Rhododendrons and Azaleas? These broad leaf evergreens are
laid back and like to take it slow and easy. Do not fertilize them with
quick release nitrogen fertilizers, it could kill them. Instead give
them an organic snack, like Millorganite or well rotted cow manure or
compost. Millorganite is an organic fertilizer made of granulated sewage
sludge.
No it
doesn’t smell any worse than other fertilizers, and plants like it
because it is plant and soil friendly. It won’t burn the plants, and it
actually reactivates the micro-organisms in the soil. That’s a good
thing. Most full service garden centers carry Milorganite.
A long
time ago somebody let the word out that Rhododendrons are acid loving
plants, and people are always asking me if I think their struggling
Rhododendron needs more acid. The answer is no. Your struggling
Rhododendron probably needs a great big gulp of oxygen around it’s root
system.
Rhododendrons do not like wet feet. They don’t even like high humidity
let alone wet soil around their roots. They like to be high and dry, and
like an unobstructed flow of oxygen to their roots. You can accomplish
this by planting them in a bed raised at least 10” with good rich
topsoil. They will be smiling from branch to branch.
A few
years back my friend Larry and I had several hundred small Rhododendrons
that we were going to grow on to larger plants. We planted most of them
in Larry’s backyard which is fairly good soil, but a little sticky. We
didn’t have room for all of them so we planted the last 105 down the
road from my house in a field we were renting. (Never heard of anybody
renting a field? You should get out more.)
This
location had absolutely no water for irrigating and the soil was very
dry and rocky. Other plants at that location often struggled during the
dog days of summer due to the lack of water, but those Rhododendrons
were as happy as pigs in mud. They out grew the ones at Larry’s house by
twice the rate and we sold them years earlier than the others.
My point?
Rhododendrons don’t like wet feet. They do well in the shade, but
contrary to popular belief they do even better in full sunlight.
Michael
J. McGroarty is the author of this article. Visit his most interesting
website,
http://www.freeplants.com
and sign up for his
excellent gardening newsletter. Article provided by,
http://gardening-articles.com
