Most houseplants resume growth in March. Some broke their torpor
in late February. Water them to support the change, and fertilize.
Water
Since a plant uses water based on how many leaves it has and how
much light there is to break water into its basic elements, a pot
that didn't dry down for 3 to 4 weeks in the dead of winter may
once again need water weekly as spring begins. Check for water
needed by pot weight or the limpness or firmness of the plant's new
growth.
We water the jade at right and most other houseplants
according to the plant's water use, not a calendar count. The more
hours of light there are each day and the more leaves it has, the
more quickly it uses up the water its pot can hold. So we water
when the pot begins to lighten and the jade leaves change from
plump to thin. That's every month or so in winter but more often
beginning in March. (The history of this jade's cut-back...
... and the whole story in short: Cold killed its top one
fall, so we cut it back, and it grew back. Three years later, cold
killed it back again, more extensively. Then, we decided to divide
it as well as cut it back hard. Photos are below, left to right:
From the beginning of the story, after the first cold caused us to
cut, after the second cold and division and cut, and finally one of
the sections one year later.
Water
thoroughly every time a plant needs water.
A pot filled with roots and loose potting soil can hold about 1/3
its own volume of water. For this jade's pot that's about as much
water as is in the bottle next to it in these pictures. Once it has
been given that much water it can hold no more and the excess
begins to seep out the drain hole.
Gradually dropping oldest leaves: A cry for fertilizer
When we see the older leaves of a plant turning pale and
withering away even though they're in good light we know the plant
is cannibalizing its own older tissues to build new. Time to
fertilize.
Below: This Kalanchoe 'Chocolate Soldiers' hasn't
had any fertilizer in the year it's been growing on from a cutting.
Only now has it begun to steal from its lowest leaves to create
new. Time for fertilizer.
Note: The photo's not fuzzy! The plant's covered with
fine hairs, a defense against hot dry seasons in the species'
homeland. Read the fuzz on a plant as a cue: like succulents, they
need to dry down a bit between waterings.
The sugar (carbohydrate) a plant
makes from carbon in the air and
hydrogen in water turns into
cellulose that builds new cell
walls.
Other essential building blocks
including as nitrogen, phosphorus,
potassium and "micronutrients"
(iron and others) come from
what's already in the plant or from
soil minerals or from fertilizer.
Since the potting mixes we use
to provide good drainage do not
contain mineral soil but bark and
peat, fertilizer's important to
support new growth.
Which
fertilizer? Balanced formula with micronutrients
For potted plants we use fertilizer that contains micronutrients
as well as the big three elements -- "trace" elements such as iron
and copper as well as nitrogen, phosphorus and potassium. Read the
fertilizer label to learn if it contains not only the big three but
the others, too. Some organic fish- or seaweed products are good.
7-7-7 African Violet Plant Food and Miracle Grow for
Acid Loving Plants fit the bill, too. (Even though fertilizer
is not "food." It's more like vitamins. Only the plant can
make its food -- sugars and carbs from sun, water and air.)
Below: 7-7-7 means 7% each of the big three nutrients
nitrogen, phosphorus and potassium.
