Humidity and light keep a Boston fern in fine
Any tips on overwintering Boston Ferns indoors? I
trimmed their dead leaves and gave them a shower yesterday. They
look pretty happy now. How often should I water them? When they
were outdoors, I watered them everyday. Should I fertilize at
Give them the best light and humidity you can. The best place
for them may be in a bathroom with a south or east facing window.
Keep them away from heater vents. Even so, it's unlikely they'll be
receiving as much light or humidity as they would get outdoors or
in a greenhouse. They'll have to skinny down by losing some leaves.
Expect more shedding, and the need for more grooming sessions.
Standard rules for watering interior plants apply to Boston
ferns. How much water they need is determined by the size of the
pot and number of leaves there are to take up water.
Put water into a measured container and pour it slowly over the
soil surface until it begins to seep out of the drainage holes. Let
water sit in the catch tray for just twenty minutes, while light is
on the plant, to see if more water is taken up into the foliage.
Then pour off the excess. Note how much you used and how much you
poured off. Each time you water, apply that same amount
How frequently the plants need water is directly dependent on
how much light they get. The better the level and duration of
light, the more water they'll use. Unlike some plants that need
periods of warmth and drought, Boston ferns like steady moisture on
their roots, so don't let the soil dry down between waterings.
Water whenever the soil surface begins to feel warm and dry, or the
pot loses water weight.
Don't fertilize in winter unless you have the plants under
I planted an arborvitae hedge two years ago. Recently, I
noticed some of the bushes had brown spots on the bottom about 12
by 12 inches. I believe these are from dog urine. I think the dog
is cooperating now but what can be done about the brown spots? The
bushes are very healthy otherwise. Also, what fertilizer do you
recommend and how often should I apply it next year?
Dog urine burns foliage. Needles and twigs in those spots are
probably dead, but the plant can eventually fill those spots with
new growth from branches nearby. This coming March, cut out the
brown. That will allow light to reach into the gap to stimulate
adjacent buds. You can even bend and tie in a few flexible limbs,
to speed the process.
What kind of fertilizer you use isn't tied so much to the plant
as to the soil. If a soil test through shows that an area is
deficient in phosphorus or potassium, you'll use a formulation that
compensates for that. High phosphorus- and high potassium
fertilizers have relatively high second or third numbers -- 5-10-5
or 6-24-24, for instance.
However, don't use such fertilizers unless you have a soil test
that indicates a deficiency. Instead, use a balanced fertilizer
such as 10-10-10 or 2-2-2. If it's a fertilizer that indicates it
is slow release, or formulated with micronutrients for acid loving
plants, all the better in your alkaline soils.
No matter which fertilizer you use, apply it so it can be taken
up by the plant while it is in most active growth. Spread slow
release formulations such as Osmocote or Driconure in late winter
or early spring. They will then be dissolving or breaking down
throughout the April to June flush of growth. Spread water soluble
products, granular or powdered, two or three times at intervals
from mid-April to early June.
Whatever you use, scratch it into the top few inches of soil or
make sure it's covered by moist mulch so that it will melt or
Apply enough so that every hundred square feet of soil surface
over the root zone receives about two-tenths pound of nitrogen
during the shrubs' growth period. The nitrogen content of a
fertilizer is given in the first number on the three-part formula.
A 10-10-10 contains 10 per cent nitrogen, and two pounds of that
product supplies the needed two-tenths of a pound of nitrogen. A
2-2-2 has two per cent nitrogen, so you need ten pounds for each
100 square feet of ground.
Green thumbs up
to evaluating a landscape now. What looks good in December is
probably a keeper. What looks bad now will compromise that scene's
appearance for three months. Does that plant's spring bloom or
summer luster really compensate for this long spate of ugliness? If
not, start looking now for spring and summer bloomers that also
carry their weight in winter.
Green thumbs down
to that feline compunction that causes a cat to begin each
houseplant-eating episode with an attack on an undamaged leaf. I
could grant a cat one leaf at a time, to be chewed off in stages
over a week or so. What riles me is that wasteful progression to
the point where every leaf is just a little bit tattered.
Originally published 12/25/04