Azaleas can be either evergreen or deciduous.
Deciduous Azaleas are known as Mollis or Exbury Azaleas. They
bloom in the early spring with vivid orange and yellow colors.
They can be grown from seed if the seeds are collected in the
fall and sown on top of moist peat at about 70 degrees F.
Evergreen Azaleas are known as broad leaf evergreens
because they are do not have needles. They bloom later in the
spring, and are usually propagated in the fall over bottom
heat, discussed in detail at http://www.freeplants.com Rhododendrons are also broad leaf evergreens and are
also propagated over bottom heat in early winter.
The best time to prune Rhododendrons and Azaleas is in
the spring right after they bloom. These plants start setting
next years flower buds over the summer, so late pruning will
cost you some blooms next year, so get them pruned as soon as
they finish blooming. It's also a good idea to pick off the
spent blooms so the plants don't expel a lot of energy making
seeds, unless of course you'd like to grow them from seed. But
keep in mind that they don't come true from seed. 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
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.
About The Author
If you have questions for Mike McGroarty visit his website,
http://www.freeplants.com and post them on the message board
where you can learn lots of gardening tips and communicate with
other gardeners. While at his website you can learn how to
start your own profitable backyard nursery. If you would like
a copy of Mike's booklet, "The Secret of Growing Landscape
Plants from Scratch", send .00 to: Garden Secrets, P.O. Box
338, Perry, Ohio 44081
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