For Christmas and Chanukah: Oranges as Houseplants 

Sara Williams


Oranges first found their way into Europe from Asia during the
Renaissance.  They became the status symbols of the yuppies of
the day and were wintered in what were appropriately called
"orangeries" - the prototype of the modern greenhouse.  Each
summer the container-grown trees were cumbersomely removed from
the orangeries to summer in proud geometric array in the formal
gardens of the estate.

Although few modern homeowners can afford the luxury of housing a
full-grown orange tree, there are several dwarf varieties which
are well adapted to life as a houseplant, given a sunny,
south-facing window.

What to Expect
All have lovely white, star-shaped flowers with 5 petals and
prominent stamens.  Depending on the variety, the flowers are
produced either singly or in clusters of up to 5.  An added bonus
is their fragrance and waxy texture.

The handsome foliage is dark green and leathery.  Both thorny and
thornless types are available.  Most are under 1.8 m(6 ft) in
height.  All produce fruit but the fruit may take up to a year to
develop.  

Oranges abound with what are called "aromatic oils" which give
them their typical citrus smell and taste.  The presence of these
oils is indicated by what appear to be transparent patches in the
leaves and stems.

The Dwarf Varieties
The Calamondin orange (Citrus x citrofortunella mitis) is
probably the most popular citrus in North American homes.  A
hybrid from the Philippines, it will begin flowering and fruiting
when only 30 cm (1 ft) high.  The fruit is 2.5-3 cm (1-1.5 in.)
in diameter, bright orange, and very bitter to eat out-of-hand. 
However, it is ideal for marmalade or preserved in syrup.  Once
ripe, the fruit will remain on the plant for many months!  It
flowers profusely and will bear flowers and fruit at the same
time.  It is slow-growing, thorn-less, and makes a branching
shrub 1-1.2 m (3-4 ft) when mature.  It is probably the most
satisfactory variety to grow indoors in that it fruits reliably
and its size and shape are suitable for the average home.

The Meyer lemon (Citrus limon 'Meyer') is 1.2 m (4 ft) in height
with 10 cm (4 in.) leaves.  Its fruit is pale yellow,
thin-skinned, and 7.6 cm (3 in.) in diameter.  It, too, begins
blooming when quite small.  The flowers are pink in the bud
stage, white when open, and exude a pleasant lemony scent.

The Otaheite orange (Citrus x limonia otaitensis or Citrus
taitensis 'otaheite') is a Chinese hybird between a lemon and a
Mandarin orange.  The flowers are white with a purplish tinge. 
The fruit is yellow-orange, 5 cm (2 in.) in diameter, and
produced in time for Christmas.  The plant itself is small and
thornless.

The Ponderosa lemon is orange-yellow with thicker-skinned,
rougher fruit up to 11 cm (4 1/2 in.) in diameter.

Finally, the sweet orange (C. Sinensis) is the only dwarf variety
with sweet-tasting fruit.  It is 1.2 m (4 ft) in height with
stronger stems, large leaves, and (alas) sharp spines!  On the
plus side, the fruit is solitary, 6-7.6 cm (2 1/2-3 in.) in
diameter, and smooth-skinned.


Care of Citrus Plants
Citrus plants are not difficult to care for.  They do well in
standard potting mixtures with good drainage.  They should be
repotted when they become root-bound, about every 2 years.  Place
them in good light with a minimum of 4 hours of direct sun daily. 
A south- or west-facing window is ideal.  Artificial lighting may
also be utilized.  Citrus like it relatively cool in winter
(10-15M-!C) and about 21M-!C in summer.  They may be placed outdoors
during the summer months. 

During the summer, citrus plants should be kept evenly moist.  In
winter they should be given less water but should never be
allowed to dry out.  Moisture should be even while fruit is
developing and plants should be misted while in flower.  Too much
water during the winter months may cause leaf discoloration, leaf
drop, or root rot.

Fertilize every 2 weeks during the summer months, when they are
actively growing, with 20-20-20 mixed according to directions. 
Plants may be pruned in spring to keep them smaller or to improve
their shape.  Growing points may be pinched to encourage a more
bushy growth.  Excessively long branches may be pruned.  Scale
insects and spider mites may sometimes be a problem.

Propagation
Citrus plants may be propagated by seeds or cuttings.  The seeds
are called pips and should be planted about 2.5 cm (1 in.) deep. 
They should be kept evenly moist with a soil temperature of
21-23C.  Seeds should germinate in 4-6 weeks and should be
transplanted when 10 cm (4 in.) high.  Seeds from store-bought
oranges are fun to experiment with but will seldom grow true to
variety.  The majority will take 7-10 years to flower and fruit
and even then may do it poorly or not at all.  Eventually, they
will outgrow your home.  Seeds from limes, lemons and grapefruit
are more likely to grow true to variety, but large mature size
and late flowering and fruiting are still disadvantages.

Tip cuttings are an easy method of propagating the dwarf citrus
varieties mentioned above.  Ten cm (4 in.) cuttings of new growth
should be dusted with a rooting compound and placed in a
perlite-peatmoss mixture.  This should be kept evenly moist (but
not overly wet) in good, direct light.  A plastic bag placed over
the pot will hold in the humidity.  Bottom heat of 21-23C is
helpful.  The cuttings should root in 6-8 weeks.