Newsletter 2(9): 8-9 (Fall 1971)
ON ROSE SEED GERMINATION
By Paul E.
following conclusions are based on hundreds of experiments over a four year
green hips may produce some viable seed, proper ripening is necessary for good
- Seeds of
hardy varieties-tend to ripen quicker than those of tender varieties. Some
varieties may never color up, especially some yellow hybrid teas.
hips threatened by a severe freeze can be cut with some foliage on
6"-12" stems and ripened in damp perlite under artificial lights. By
this means the hybridizing season can be extended about a month.
general, "floaters" will not germinate, but this is not true of small
seeds of such varieties as The Fairy and the hybrid rugosas.
- Of a
given variety, large seeds germinate better than small ones; and seeds sticking
well out of the pod so that they are easily rubbed off, germinate poorly.
germination has consistently given me better results than any indoor system I
have been able to devise, so far. Seeds planted outdoors were always protected
from extreme. cold by some insulation.
germination is improved by an after-ripening treatment of the seeds in a
plastic bag at 35°F. Such treatment in the pod is not effective,
after-ripening duration is dependent on the cold-hardiness of the variety.
Hybrid teas require about 30 days, floribundas about 60 days, and hardy
climbers and shrubs about 90 days.
content during after-ripening is very important. Optimum moisture content can
be obtained by lightly "blotting" off excess moisture with a paper
towel after the floatation test. Air drying for 3 hours drops germination to
near zero, and adding 50 drops of water to 100 seeds does likewise.
after-ripening shortens the time from planting to germination.
- Dropping the temperature to 16°F. or lower during after-ripening drops the
germination drastically. This is true whether the seed is in the hip at the
time or in a plastic bag.
- Germination of open-pollinated seeds varies tremendously, depending on the
variety. In a test of 15 varieties with 90-day after-ripening, germination
varied from 66.7% for "The Fairy", to 0.5% for "Sunday
Best". With a 60-day treatment "Chuckles gave a 79.5 germination.
treatment of seed (normal dental photographic exposure) drastically reduces
germination and induces large percentage of deformed seedlings.
following observations cannot be considered absolutely conclusive because of
the limited scope of my experiments:
in "Chlorox" solution showed no advantage over floating in water.
of. small amounts of "Spergon", "Rootone" or "Rapid
Grow" during after-ripening showed no advantage.
with. "Gibrell" (potassium gibberelate) drastically reduced
- After-ripening in an air-tight bottle appeared to drastically lower
experimentation has enabled me to improve my germination by about 300%, there
is still room for improvement and I realize that my conclusions may not be
valid under different test conditions. Your comments and suggestions will be
most gratefully received.