Friday, January 20, 2017


Spinach has specific growing requirements and if you procrastinate you will miss out on this delicious  and nutritious green.

Spinach needs a good 6 weeks of cool weather.  It can be planted when soil temperatures are 55-65 degrees or as soon as your ground can be worked  It will not germinate well in soils that are above 70 degrees.  It is not a summer crops  It can be sown again in fall and protected under row covers for late fall harvests.

The spinach plant is daylength sensitive.  This means it waits until there are a certain number of daylight hours and that is the signal to bolt or set seed. When daylight hours reach 12-15, your spinach knows it's time to produce seeds. It is at this point that you can determine the sex of you plants if that is important to you.  If you save seed that will be a factor. You need both male and female plants.

 Keep in mind that spinach is wind pollinated and the pollen is very fine and travels far.  You can only save seed from one variety and must have both male and female plants.  Besides daylight hours, spinach doesn't like warm and then cold again weather.  Fluctuations in temperature between warm and cool will  encourage early bolting.

Types of Spinach

There are two types of spinach leaves:  smooth and savoyed or wrinkled.  Some people prefer the smooth, but I like both and plant some of both.  The seed  type can be used to determine the leaf type.  The smooth seed produces wrinkled leaves while the prickly seed produces smooth leaves.  

Planting Guides

Spinach should be seeded directly in the garden it does not like to be transplanted. It can usually be seeded 3-4 weeks before the last frost date which for me is May 14th.  If I count back 4 weeks, that means around mid April I can begin planting.  If weather permits and the soil has warmed up, I plant even early and use a low tunnel or floating row covers.

 Give the plants ample space.  No more than 4 per square foot.  It is a good idea to successive plant every couple weeks in early spring but stop planting if you do not have 6 weeks of cool weather remaining.  It does not like temperature above 75.

Plant in a soil with plenty of organic matter worked in and a dry organic fertilizer.  I use a mixture of bone meal and blood meal.  Fertilizing is not usually necessary after that as long as you prepared your soil.  Mulch around the seedlings and water regularly.  Spinach is very cold hardy and can survive in temperature as low as 15-20 degrees. Spinach planted in zone 5 in fall will die down in winter and come back early spring.


I usually harvest the outer leaves so I can have a continuous harvest but the entire plant can be harvested.  The younger the leaves, the more tender and better flavor. Harvest in the morning.  Slightly rinse the leaves and store in a plastic container or plastic bag.  Do not clean thoroughly until you are ready to use the spinach.  

Spinach is store with lettuce and sorrel  in a large plastic air tight container.

I enjoy spinach raw in spinach salads or mixed with other greens. It's also very good in place of lettuce on salads.  It is very nutritious with vitamins A, B6, C, folate, calcium, and iron. 

Pests and Disease of Spinach

Spinach can get leaf miners and Mosaic virus which is called spinach blight.

Leaf Miners

Brown  and tan blotches on the leaves are a sign of leaf miners.  The adult is a fly that pupates in the soil and lays white eggs on the under side of the leaf.  The larvae called maggots (yuck) enter the leaf and create leaf mines.  They are hard to kill with pesticides because they are inside the leaf.  I pull off infected leaves so that the larvae don't mature and feed to livestock or throw in the garbage not the compost pile.  To help control leaf miners, cultivate or turn over the soil where you plant spinach, chard, and beets to kill the pupae.  Row covers can also keep the adult from laying eggs on the leaves.

Plants infected with spinach blight just need to be pulled up.  There is no cure for viruses and they can be spread by insects feeding on various plants. Avoid planting spinach with cucumbers and tomatoes. I companion plant spinach with onions.

Varieties of Spinach

Bloomsdale Longstanding (OP):  This is the standard for spinach.  It's my favorite.  It has deeply savoyed (wrinkled leaves) and is deep green and wonderfully flavored for salads.  The leaves are upright off the ground.  

Space (F1):  A smooth leafed spinach with spoon shaped leaves. 

Tyee (F1):  This is slightly savoyed leaf.

Giant Noble (H):  Heirloom of 1926.  Very large leafed, tender

Melody (F1):  Also very large leaves with upright growth

Butterflay:  Another good variety but low to the ground and more susceptible to problems because of that.

There are lots of other varieties to try but my garden will always have Bloomsdale Long Standing along with a other varieties.  Be sure to try a smooth leaf variety.  It will make that spinach salad much more interesting.

Summer Spinach

After all the talk about cool weather, both New Zealand Spinach and Malabar Spinach that can be grown in the summer.  The reason is that neither are a true spinach.

Malabar Spinach is a perennial vine in warm climates.  It prefers hot humid weather.  The leaves are used like spinach in salads.

New Zealand spinach needs warm soil to germinate and does not tolerate frost .  The leaves can be substituted in cooked dishes for spinach.  It is very high in oxalic acid which causes a flavor many people do not like.

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