Fertilizing
Roses
A
rose fertilization program involves applying a quality rose
fertilizer in spring and throughout the growing season.
Roses are heavy feeders; they
take lots of nutrients from the soil. On top of that, many
nutrients leach from the soil very quickly. So the trick
is to feed roses often and lightly. But, stop feeding 6 to
8 weeks before the expected first frost in autumn.
What and
When to Feed?
Feed roses often and
lightly. The big 3 nutrients are: Nitrogen
which promotes healthy green growth; Phosphorous,
which is vital to strong root growth and flower production; and
Potassium,
which is needed for vigorous growth.
For Hybrid Teas,
Grandifloras, Floribundas, Polyanthas, and Climbers:
Apply 1/2 cup of 10-20-20 or 10-20-10 per bush, three times per
year. First application in late March or early April; second
application in May; third application in late June or early
July. Alternatively, you can add 1/4 cup every two weeks
For Miniatures:
First
application in early April using 1 tablespoon of 10-20-20 or
10-20-10 scattered around each plant and scratched in lightly.
For the second application in early June use a soluble 20-20-20
fertilizer such as Rapid-Gro, mixed according to the directions
on the package; use 1 cup of this solution around the base of
each plant. The third application early in July is the same as
the second. Alternatively, you can use 1/2 the amounts
divided over 6 feedings.
Old Garden Roses and
Shrub Roses: Most of these don't need much
fertilizer. Once in the early spring with a general all purpose
20-20-20 will hold them for the year. For repeat blooming
types, a second feeding can be applied after the spring flush of
bloom is done.
The
Macronutrients
The secondary macronutrients
are sulphur, calcium and
magnesium.
Use of a high quality rose fertilizer will ensure that these
macronutrients are made available to the roses.
Of these secondary
macronutrients, magnesium is of substantial interest to the rose
gardener. Magnesium sulfate, provided in the form of Epsom
salts, is a time-honored secret for intensifying flower color,
increasing flower production, and flushing harmful salts through
the soil. Add epsom salts at the rate of 1/2 cup per plant
per month.
The
Micronutrients
The seven micronutrients are
iron,
manganese, zinc, copper,
molybdenum, chloride, and
boron.
Ensuring that your soil is of the proper pH for your roses will
ensure that plants can access micronutrients in the soil.
Especially in areas where soil is alkaline, you may need to
correct the pH and/or foliar feed with a fertilizer that
contains chelated micronutrients.
Both macro and micronutrients
are plentiful in compost and composted manures and leaf
mold. Topdressing annually with a good layer of compost
should be sufficient for most established roses.
American
Rose Society's "alfalfa tea" for roses!
Alfalfa tea is a great fall potion that
doesn't interfere with normal fall processes. Alfalfa tea
releases a growth hormone that makes everything work
better.
- Just add 10 to 12 cups of alfalfa meal or
pellets to a 32-gallon plastic garbage can (with a lid)
- add water, stir and steep for four or five
days, stirring occasionally.
- You may also "fortify" with 2
cups of Epsom salts, 1/2 cup of Sequestrene® (chelated
iron, now called Sprint 330) or your favorite trace element
elixir.
- The tea will start to smell in about three
days. Keep the lid ON.
- Use about a gallon of mix on large rose
bushes, 1/3 that much on mini's. And keep the water going.
- When you get to the bottom of the barrel,
add water to fill it up again! One load of meal or pellets
will brew up two barrels full, but add more fortifiers for
the second barrel.
You'll see greener growth and stronger stems
within a week.
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Watering
Roses
Water
roses less often and deeply. The key to watering roses
is to water deeply, with the goal of providing roses with one
inch of water per week (a rain gauge is very helpful in knowing
how much extra watering to supply to augment rainfall). If
you have properly prepared your rose beds with additions of
copious amounts of organic material, and inch a week is all you
will need.
Roses are deep-rooted plants,
and the goal is to encourage the development of roots which grow
as deeply as possible into the soil. If one makes
the mistake of frequent, light watering, the result will be a
plant with shallow roots, ill-prepared to handle the drying of
the upper layer of soil during droughts.
Note: monitor
newly-planted roses carefully, as they will not have yet
developed deep roots during the first growing season.
Water from below or in
the morning. Damp, cool conditions are a breeding
ground for the diseases which trouble roses. Your goal is
to ensure that rose leaves are dry by dusk. You can either water
in the morning, or water the soil around the plants using a drip
irrigation system.
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Grooming
Roses
Grooming
is a regular feature of rose culture. Removing faded flowers
after each flush of bloom improves plant appearance and prevents
fruit development. Flower buds should be removed for the first
two months after planting to encourage growth and help to
establish a new plant. The first flowers allowed to develop
should be cut with short stems to leave as much foliage as
possible on a new plant.
At any time, remove dead wood
and canes showing disease symptoms. Cut the affected part back
to healthy wood and remove it from the garden. Additional
pruning should be done each year in early spring just as the
growth buds start to swell. Vigorous shrubs may need
pruning twice a year for size control. To avoid dieback and
encourage rapid healing, pruning cuts should be made just above
a dormant bud. For details and examples on pruning, see
the Pruning Techniques
article.
Winter Care
Although old garden roses and
some shrubs roses defy even the frigid winters in the far North,
most modern bush roses are too tender to tolerate winter's
worst. In zone 5 or colder, you should protect rosebushes
from winter cold See Winterizing
Roses for various methods of rose protection.
Pruning Modern Bush Roses
If you live in places where
there isn't snow in winter, prune your rose about 4 to 2 weeks
before the last frost date (check the map).
Shorten healthy canes to 8 to
24 inches tall and cut out weak or damaged canes, keep only the
3 or 5 thickest and darkest green ones- these are the most
vigorous ones. Make cuts with clean, sharp handheld shears,
cutting at a 45 degree angle just above outward-facing buds.
Keep in mind that every time
you cut off a fresh or faded flower you actually prune the bush
and influence its growth. You must remove the faded blossoms
properly to stimulate new growth and thus more flowers. When
cutting a flower use sharp handheld shears and cut at a 45
degree angle just above the first large leaf with 5 leaflets
(not too close, not too far, about 1/4 of an inch). New growth
emerges from the axil of this leaf and produces more blossoms.
Hybrid Tea Roses and Glandifloras are pruned in this way.
Pruning Floribunda, Polyanthas and
Miniature Roses
Cut back canes to within 6
inches of ground every 3 years to renew vigor. Cut out dead
canes and prune weak canes to 6 inches every year.
Pruning Climbing Roses
In cold areas, remove oldest
and weakest canes at bases while dormant, leaving a total of 5
to 8 of the newest, strongest canes. Cut side branches back to 3
buds. Partially dig up roots, tilt plant, and lay canes on
ground, burying with soil to overwinter (See
Winterizing
Roses).
In warm areas, just let it grow
until it reaches the size that you want. Then, every year, when
it's time to prune, cut the excess if it grew too much.
Cut out the bad canes and prune one of the oldest canes to 8
inches tall, prune one of the oldest canes per year this way.
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Treating
Rose Problems
A
schedule of rose maintenance includes spraying and irrigation
each week, grooming and fertilization after each flush or
growth, pruning and mulching during each winter season. This
caring for the health of the rose plant can provide an abundance
of bloom that extends through the growing seasons for many
years.
If you grow hybrid teas, you
must resign yourself to an additional never-ending regimen of
spraying for fungus problems and insect pests. However,
any rose can be affected with powdery mildew or black spot
fungus diseases in particularly humid seasons.
Various beetles also have a
craving for rosebuds, but the key to this is to prevent them by
treating your lawn and flowerbeds for beetle grubs. The
trick is to kill them before they grow...See the
Plant
Problems pages for more details.
At the first sign of fungus
problems, or before any signs appear in areas where you know you
have a problem, start spraying every 7-10 days, and after rains,
with a mixture of a few drops of dishwashing liquid and a
tablespoon of baking soda to a quart of water. If that
doesn't nip it in the bud, so to speak, try a mix of 1/10
strength skim milk. It must be skim milk to work -
anything else will go rancid and attract more problems to your
garden. If that doesn't do it, then it's off to the garden
center for systemic fungicides. See the
Plant
Problems pages for more details.
The dishwashing liquid
treatment also works for most small insects. If you do get
a horde of rampaging beetles or other voracious types, check the
Plant Problems article
for information on insecticides and other insect controls.
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