Consulting Rosarian Tips for May
Roses should be showing lots of
new growth after the April snows. First on the list of May tasks are pruning and
cleaning rose beds and then fertilizing. If you had to shovel prune roses, then
the purchase of new container roses from a local garden center might be on your
list too. By the end of May or before, you might meet up with aphids. If you
purchased any bare root roses, they should be planted by now.
Pruning — Sharp tools make
nice clean cuts and allow for more enjoyable pruning. Are your shears sharp,
oiled, and properly aligned? Long-handled loppers will give you more leverage
for cutting larger, thicker canes. A folding pruning saw will work on canes that
are too large for the loppers. Keep pruning shears clean by applying rubbing
alcohol or make a solution of 1-part household bleach to 9-parts water. After
cleaning is finished, rub a thin coat of oil on the blades and working parts to
prevent rust. When pruning is completed, clean up beds and remove all debris.
Don’t forget to seal canes with Elmer’s glue (not school glue) or colored nail
Planting — Choose an area
that gets at least 6 hours of sun daily with plenty of air circulation and space
around the plant with good drainage. Roses should not compete with other shrubs
or trees for nutrients. Container roses are grown in a greenhouse environment.
Before planting, they need to be hardened-off or acclimated to outdoor
temperatures by placing them in a protected area for a few days. The danger of
frost should be over by May 15.
Dimensions for digging the hole are 18 to 24 inches across and 14 to 18
inches deep. To determine the soil level, place potted rose in the hole and
lay a stick or handle of a tool across the hole. Grafted roses should be 1
to 3 or even 4 inches below the soil level; the branching point of own root
roses should be 1 to 2 inches below the soil level. If the rose was
purchased in a cardboard or plastic container, remove the container before
planting. Water well and begin to backfill. Using your hands, gently firm
the soil; do not tamp the soil down with your feet as it will destroy the
soil structure. Monitor the moisture level around the bush to avoid
dehydration from sun and wind.
When shoveling out a rose, can another rose be planted in the same hole?
Yes. After the rose is removed, check for roots that were left behind.
Enlarging the hole will uncover additional roots, rocks, or other debris. If
the previous rose was doing poorly in that location, perhaps a soil test is
needed. Amend soil before placing the new rose in the hole. Try to include
as much of the root ball as possible. If soil falls away from the roots,
then plant it as a bare root rose. The best time to transplant established
roses is when the soil is workable in March and April. Transplanting can be
done during warmer temperatures, but the prep work (watering rose the day
before, digging the hole, and amending soil) should be completed before
moving the rose. Frequent watering is recommended afterwards until the rose
has taken hold and there are no wilting leaves.
Fertilizing — The first
application of fertilizer is in early May with continued applications every 4 to
6 weeks afterwards. The last fertilization is in mid-August. Roses will need to
be watered the day before to hydrate roots and then watered afterwards. There
are several types of liquid and organic fertilizers. Read application
instructions to ensure that the correct amount is given and remember that
miniature roses require less than the regular amount of other roses. If the
garden center has not added fertilizer to their container roses, then organic
fertilizer like Mile-Hi Rose Feed can be added when planting.
Watering — When bushes
begin to leaf out, increase water cycles and apply mulch to keep plants cool.
Insects/Pests — As warmer
temperatures increase, watch for pests like aphids that can be controlled by
squishing or with strong water sprays.
For rose questions, contact
Consulting Rosarian in your area.
Roses in Review
Every year, the American Rose Society
conducts a survey of roses and how they grow in gardens around the
nation. The national results will be published in a future
edition of the American Rose Society magazine. The results for
the Rocky Mountain District (Colorado, Idaho, Montana, Utah and
Wyoming) are available now! The first file contains the
results sorted by variety, classification, garden rating and
exhibition rating. The second file contains the comments
provided by the reviewers.