A Gourmet Diet for Bay Area Roses - Garden Club of Palo Alto

A Gourmet Diet for Bay Area
              Roses
            By Rayford Reddell

 In 24 years of growing roses, not a summer has
passed without gardening friends calling to report
that something is terribly amiss with their roses. “I
can’t imagine what’s gone wrong”, they lament,
“the first flowers were magnificent, and there were
armloads of them, but now there’s not a handful of
roses in the whole garden and the bushes look
exhausted.”

 When I ask when the plants were last fed, I’m
regaled with the formula used in early spring,
which often sounds delicious, horticulturally
speaking – bone meal, hoof and horn, and a
generous blanket of organic mulch that includes
aged manure. As patiently as I can, I explain that
the spring banquet was indeed grand and point out
that the roses obviously appreciated it as shown by
that magnificent spring flush of bloom.

 If you want more blossoms, you’ve got to feed
again’ and again after that – right through October.
And you cannot keep feeding them the same meals;
roses appreciate certain food at precise times.

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The conversation often slows here, but resumes
with whether or not I am willing to prescribe a rose
diet for their garden. After serving as a rose
dietitian for 24 years, I’m ready to offer a feeding
program for established rose bushes and shrubs
throughout the Bay Area.

 For new plants, sickly plants and miniatures, cut
all fertilizer dosages in half. There are other
caveats to my rose diet:

 First, it assumes that rosebushes have been well
mulched with organic materials such as compost,
wood shavings, and aged manure (chicken and
turkey are best, but steer will do, preferably a
combination). Mulch is not only nutritious on its
own, it provided the perfect medium over which
concentrated fertilizers should be applied.

  Second, gardeners must grasp the significance of
N, P, K – the three most essential elements in soil
fertility (always expressed in three consecutive
numbers on labels of all fertilizers, granular or
liquid).

 N stands for nitrogen, which is not only a growth
stimulant, but also essential in the formulation of
chlorophyll and a regulator in plants’ uptake of
other nutrients.

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P symbolizes phosphorus, which stimulates root
formation and flowering. Phosphorus also hastens
plant maturation by converting starches into sugars.

  K signifies potassium (potash), which is
important for the development of stems and leaves.
It also increases plants’ disease resistance and
hardiness.

  Next, understand that I am a pig when it comes to
rose blossoms; I want as many as possible from as
early in April as I can bring them to bloom until as
late in November when rain and chilling
temperatures take the upper hand. Consequently,
I’m a heavy feeder.

 As far as I’m concerned, winter is officially over
on the last day of February, after which I’m free to
put pressure on my roses to start performing. I
begin the first week of March, in full knowledge
that I’m rushing the season and that an
unseasonable late frost (not unheard of in Sonoma
County) may nip my efforts in the bud. The chance
of that happening in San Francisco, however, is nil.

  Finally, my suggested feeding schedule is for
modern roses only – those that repeat their bloom.
I use the identical program for once-blooming
heirloom roses, but only through June. Otherwise,
during:

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MARCH & APRIL
 First week – feed with granular, water soluble
fertilizer concentrated in nitrogen 31-0-0 (a slow-
release formula), 33.5-0-0 (ammonium nitrate), 21
0-0 (ammonium sulfate) or 15.5-0-0 (calcium
nitrate).

  Apply granular fertilizers in accordance with
manufacturers suggested rate and around the drip
line of rosebushes – that imaginative circle that
would exist if bushes were dripping wet. Granular
fertilizers can be spread directly on the ground (as
opposed to being diluted first) as long as they are
watered well.

 Third week – feed with ¾ cup Epson salts per
bush and water in well. Epson salts (properly
called magnesium sulfate) are activators for plant
enzymes essential to the growth process. In
rosedom, that translates to vibrant red growth
emanating from the base of rosebushes (basal
breaks, in rose lingo).

 If you have only a few rosebushes, buy Epsom
salts in the corner grocery or pharmacy; it’s
inexpensive. If you have more than a dozen roses,
you might want to invest in a bag of industrial
grade magnesium sulfate. Although it doesn’t meet
the purification standards of pharmaceutical quality

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Epsom salts, your roses will not know the
difference.

                   MAY & JUNE
 First week – feed with granular, water soluble,
balanced fertilizers such as 10-10-10, or 15-15-15,
or 20-20-20, whichever is on sale. During the bulk
of rose season, rosebushes need equal amounts of
nitrogen, phosphorous and potassium.
 Third week – feed with ½ cup Epsom salts per
bush.

                 JULY & AUGUST
  First week – feed with granular, water soluble,
balanced fertilizers such as 10-10-10, or 15-15-15,
or 20-20-20, more likely on sale now.
  Third week – feed with fish emulsion at the rate of
one tablespoon per gallon. Dissolve emulsion in
water and pour 2 gallons of mixture around the drip
line of each bush.

           SEPTEMBER & OCTOBER
 First week – feed with granular, water soluble 0-
10-10. This mixture is a favorite among garden
plants, not just roses, because it encourages no new
growth (the 0 signifies an absence of nitrogen).
The concentrations of phosphorous and potassium
assure continued bloom and harden wood in
preparation for winter pruning.

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Third week – feed with fish emulsion at the same
rate prescribed for July and August.

  Don’t apply fertilizers after Halloween, even when
seasons are extended, the soil around properly fed
rosebushes holds enough nutrients to bring those
last rose blossoms to buxom maturity.

 There are other foods that roses find tasty.
Chelated iron is considered by many rosarians basic
to a well-balanced diet. Not only is chelated iron a
quick greener-upper, it is touted to be a fine soil
penetrant. There are certain trace elements such as
zinc, boron and manganese that sometimes get
depleted from garden soil. A soil test will tell for
certain if this has happened in which case, the soil
should be punched up.

 Finally, if your roses still seem hungry in spite of
this hefty diet, you can fertilize to your heart’s
content with additional shots of fish emulsion,
which is not only thoroughly organic, but also
incapable of burning plants. However, I am willing
to bet that no gardener in the Bay Area will have to
supplement the feeding schedule suggested, no
matter how piggy they or their roses are.

 It all works for me.

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