Early Spring!
This past winter seemed hard to people but it was
ho-hum for plants
Dear Janet,
I grow Crocosmia, having very good luck with them
although I learned recently that they aren't normally hardy here. I
do wonder if this very cold winter is going to be the death of
them? Actually I'm kind of worried about quite a few of my
perennials, after such a long cold winter. Guess you can only wait
and see on something like that.
I've collected Crocosmia seeds, strewn them on the
ground, and tried to get them to germinate indoors, but always
without success. Do they require stratification to
germinate?
D.
Dear D.,
I'm not worried for the majority of perennials. We were colder
this winter than in the recent past but still within the norm for
USDA hardiness zone 5 -- meaning our minimum winter temperature
stayed above -20 degrees F. So any plant hardy to zone 5 that was
healthy going into fall should be fine now.
The ones to cross your fingers for are plants hampered by
debilitating factors such as poor drainage or drought stress, or
species like Crocosmia and dusty miller that were overwintering
here recently because our winters have been more like the warmer
zone 6.
Crocosmia is marginally hardy in zone 5 so it's at risk even in
a normal winter. Don't lose sleep over it, but don't waste time
either. If it doesn't show growth by mid- to late April, buy
more.
Crocosmia seed doesn't need a cold period before it sprouts. It
germinates in just 14 to 28 days, at about 70F. However, seedlings
are more tender than established plants. If you sow the seed as it
ripens in fall it will sprout during November's Indian summer and
the seedlings will die during winter. So collect the seed in fall,
store it inside and sow it in spring. After a season's growth the
plants are more likely to survive winter.
Dear Janet,
In summer of 2002 we planted three PJM Rhododendrons.
These were planted in July when our home was professionally
landscaped. At planting time we were told not to fertilize during
2002. We have clay soil beneath a layer of top soil and we are
careful not to overwater. The question is: when should we fertilize
and what is recommended. I know they require an acid soil and we do
have Miracid on hand. Do we use only this or is there a better
product? Also how often should we apply?
Final question: When is best time to prune, if at all
during this coming season?
K.B.
Dear K.B.,
Minerals essential to vigorous rhodo growth don't dissolve when
the pH is so high as it is in Michigan, above 7.0. What won't
dissolve, the plant can't absorb. So rhodos and azaleas wither
away. This may not be apparent to you but it is very clear to the
practiced eye. I regard most such shrubs here as examples that
could be featured in the horticultural equivalent of an ad asking
for donations to feed starving children.
For that reason, the rule about not fertilizing during a woody
plant's first season can be disregarded for rhodos and azaleas --
they will not root out readily into the native soil, so will always
rely on supplements. Once a month, April through July, use Miracid
or another water-soluble formula for acid-loving plants. Better
yet, apply it weekly at quarter-strength, sprinkling it onto the
leaves as well as the soil. Also spread an acidic mulch or
slow-release fertilizer under each plant every year. The mulch
might be an inch of cocoa hulls or coffee grounds. The fertilizer
could be a quarter-cup of Osmocote or dusting of cottonseed meal
under the mulch.
The best time to prune spring blooming shrubs such as these is
right after they bloom. Start pruning once they reach the size you
want them to be, shearing them back by the same number of inches
they have shown they are likely to grow each year in your garden.
After shearing, cut every fourth or fifth branch back a few inches
further, to keep new growth coming from well within the sheared
outline.
Short reports:
The sap's up!
You can still prune the "bleeder" species such as maple, beech,
birch and grape but be prepared for the flow. It doesn't harm the
plant but does affect the soft-hearted gardener, and can gunk up
your clippers or saw.
Launder your gloves or buy new, regularly.
It's worth the price to keep your hands healthy. Plain cotton
gloves are probably best to avoid the all-too-common fungus
infections under the nail. If you use rubber gloves against the
dampness of spring, wear thin liner gloves under them to keep
moisture from building up in the finger tips.
Green thumbs up
to my first glimpse this year of a foraging groundhog. Much as I
dislike your irreverent snacking and prodigious digging in my
gardens, Mr. G, it is thrilling to know that our seasonal interplay
is about to resume!
Green thumbs down
to walking where it's wet or the snow melted last. The air may
be 70 degrees but the soil a few inches down is still frozen. Let
it thaw and drain a few more days, or you'll pulverize the soil
between foot and ice.
Originally published 3/22/03