by Peggy
Burch
Colorado State University Cooperative Extension
Master Gardener
Larimer County
Q: Some of our tomatoes have a large dark spot
on the bottom. What is happening to them?
A: If the brown spot is restricted to the bottom of the tomato, it sounds like
blossom-end rot. This is a result of water stress in the tomato. The condition
may be aggravated by a calcium deficiency, temperature and inconsistent watering.
The condition usually affects just the earliest fruit and probably will not
appear on later-developing fruit.
Q: Some of my perennials didn't do well this summer. A friend told me
that they probably need dividing. What is the best time of the year to do this?
A: If a plant is blooming poorly, has a lot of dead plant material in the middle,
or is cramped and pushing out of the soil, it should be divided. Dividing perennials
can rejuvenate the whole plant and give you many new plants.
Plants that bloom in the spring or very early summer do best when divided in
fall. In our area, this should be early fall so the roots can become established
before cold weather sets in. Fall dividing can be done with plants such as iris,
daylilies and peonies. Summer to fall bloomers should be divided in spring.
Plants should not be divided while it is still in bloom. If you are unable to
do any fall dividing, it can still be done in the spring although you may lose
the blooms for the season.
Q: I have a very large rose garden. Something is eating circular holes
in the edges of the leaves. What is causing this and what can I do about it?
A: It sounds like leafcutter bees. They are native bees that look similar to
honeybees. Leafcutter bees prefer plants in the rose family and can cut out
near-perfect holes in a matter of seconds. They use the pieces of leaves to
construct nesting cells for their young. The pieces of leaves are rolled into
thimble-shaped cells and packed with pollen for the young to develop. These
bees do a great deal of pollinating and control is not recommended. The damage
is usually superficial and generally does not hurt the plant. If you live in
an area where there are large populations of these bees, the plants can be covered
with mesh screening. For more information, refer to Fact
Sheet #5.576, “Leafcutter Bees”
Gardening and Insect Fact Sheets are available on-line by clicking HERE.
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