a cool season crop and belongs to the goosefoot family
along with Swiss chard and beets. Spinach is low in calories,
and is a good source of vitamin C, vitamin A, and minerals,
After washing the leaves, cook
them in a covered non-aluminum pan using only the water
clinging to the leaves. After cooking, add just a little salt
and butter, vinegar, or mustard for added flavor. Fresh tender
spinach leaves make excellent salads.
Spinach is a very hardy crop and
can withstand temperatures as low as 20 F. It can be the first
garden vegetable planted in the Spring since the seed can
germinate at low temperatures. Spinach thrives in cool, moist
conditions. It does not tolerate hot weather well and
begins to ‘bolt’, or go to seed, as daylight lengthens and temperature
increases in June.
Fresh spinach seed germinates
readily at 38-40F and may be planted with good results when
soil temperatures are 50 to 60 F. Higher temperatures will reduce
seed germination. Soil temperatures above 85 F will inhibit
seed germination. Spinach seed loses viability rapidly and should
be purchased fresh each year. Spinach should be planted in rows
12 to 24-inches apart. The seed should be placed 1/2-inch deep
and planted to have one plant every 3 to 4 inches after thinning.
One packet of seed will plant 25 feet of row. One ounce of seed
will plant 100 feet of row.
Spinach requires a soil pH of 6.0 - 6.5
and will not grow well if pH is below 6.0. Indications of possible
soil pH problems include poor seed germination, yellowing and
browning of the margins and tips of seedling leaves, browning
of roots, and generally slow growth or death of the plants.
If soil pH is too high, leaves may show a generalized yellowing,
known as chlorosis.
Spinach is adapted to a range
of soil types, from light and sandy to silty clay loams. In
heavier soils, spinach should be grown on raised beds
to improve drainage for the shallow-rooted plants. Seedling
damping off can be reduced by using raised beds. After seeding,
the soil should be kept uniformly moist. When irrigating the
garden, water in the morning so that the foliage is nearly dry
before dark. Water sufficiently to moisten the soil to a depth
of about six inches. A uniform supply of soil moisture is required
to produce high quality, tender spinach.
Spinach varieties are separated
into types with flat leaves, leaves that are semi-savoyed
(crinkled), or those that are heavily savoyed. The
flat-leafed types are used primarily by the processing industry
since soil particles are easier to wash off. The thick leaves
and ease of washing also make this type attractive to certain
fresh market consumers. Whatever type, fresh spinach should
be crisp, succulent and dark green, with a minimum of stems.
Seven R is a standard, semi-savoyed
cultivar that is best for early spring and fall plantings. Plants
are large and quick-growing. The erect leaves are good for mechanical
harvesting. It is resistant to both race 1 and race 2 of downy
Marathon has a savoy leaf. It
is better than Seven R for spring plantings since it is slower
to bolt (form flower stalks) in warm weather. The leaves are
large, dark green, semi-erect and long standing. It is used
for both fresh market and processing from late winter and spring
Melody F1 is a semi-savoyed type.
Plants are large and quick growing with very deep color. Leaves
are thick and rounded. It is resistant to downy mildew and cucumber
Vienna F1 has large, savoyed leaves
forming an erect plant type. It is best planted in the fall
as it tends to bolt in spring plantings. Grandstand has semi-savoy
leaves, is long-standing and semi-erect. The leaves are medium
large and medium green. It is resistant to downy mildew and
mosaic and is used in the spring, primarily for processing.
Tyee F1 is becoming a new standard
for savoyed spinach. The leaves are dark green with an upright
growth habit that produces cleaner leaves. It is a bit slower
growing than some other savoy types but stands well in hot weather
because it is slow to bolt. It is good for a spring crop. It
also is tolerant to downy mildew races 1 and 3.
Long Standing Bloomsdale is a
heavy-savoy type, adapted for late spring and early summer harvest.
Leaves are dark green and medium large. Plants are medium large
and erect. It is an older variety. Other Bloomsdale types, such
as Long Standing Savoy #653, have been selected for earlier
maturity and slow bolting.
If growing spinach for shipping, the
savoy varieties are best because they pack less closely than
the smoother types and retain market quality better. They are
slower to wilt or turn yellow after harvest. Smooth-leafed varieties
are easier to clean and prepare for canning or freezing.
Diseases on spinach tend to be
those that develop under cool, moist conditions. One symptom
characteristic of downy mildew is light-yellow areas on the
leaves. Infected young plants may be pale green, stunted, with
leaves heavily savoyed. During periods of high relative humidity
or rainfall, sporulation will occur, appearing as a white mass,
which eventually turns purple. Most modern varieties however
are resistant to downy mildew. White rust is a serious problem
in spinach production in the southern Great Plains and Texas.
White, blister-like pustules appear, usually only on the lower
side of the leaf. Surrounding tissue browns and dies. A few
fungicides are available for use in spinach produced on a commercial
scale. There are no fungicides registered for use by home gardeners
Insect pests include the green
peach aphid, seed corn maggot, cabbage looper, cucumber beetles
and the spinach leaf miner. Aphids can be a major problem
because they transmit virus to the spinach and are difficult
to control, especially in the savoyed leaves.
Spinach is shallow rooted. Cultivation
to remove weeds must be shallow to minimize damage to the roots.
A few herbicides are available for commercial production. For
smaller plantings, hand weeding is recommended.
Harvesting and Storage
Spinach can be harvested until
seedstalk formation. Spinach planted for early harvest is subject
to bolting as daylight lengthens in late spring and early summer.
Spinach is harvested by cutting the stem below the head or rosette
of leaves. The crinkled leaves should be rinsed thoroughly in
cold water to remove any grit soil particles. The leaves are
then bunched. Remember that Fall spinach is very hardy and
not easily damaged by frosts. Harvest dark green, tender
leaves that are 3 to 6 inches long. In your home garden, start
by picking the outer leaves and then harvest the newer leaves
as they reach the desired size. Spinach not needed immediately
for eating is best left in the field until severe freezing is