How To Grow Spinach

Plant Type: Annual
Scientific Name: Spinacia oleracea
Light: Full sun (cool weather) to partial shade (hot weather)
Soil Type: Well drained, highly organic
Soil Temperature: 40°
ph Range: 6.0 – 7.0
Watering: Evenly moist
Plant (Payson): March 15 – April 20 / August 1 – September 15
Planting Method: Seed
Germination(days): 6 – 10 days @ 40°+
Transplant: Not recommended
Maturity(days): 40 – 50
Common Pests: Aphid, Leaf Miner, Spider Mites
Common Diseases:Damping-off/Seedling blight, Downy Mildew

Spinach is a cool-season vegetable that prefers sunny locations and fertile, well-drained soil.  Spinach tastes best when plants grow rapidly and mature before the heat of summer. It has a remarkably buttery, nutty flavor when eaten raw in salads or sandwiches or added to a smoothie.  Planting a range of different types makes salads more interesting.  Harvest spinach when the leaves reach full size.  Spinach is low in calories and has no fat or cholesterol.  It is a very good source of dietary fiber, vitamins A, B6, C, folate, calcium, and iron.  Spinach is a cool weather leafy green providing high amounts of vitamin A and C, folic acid, iron, potassium, and carotenoids lutein and zeaxanthin. 

There are 2 types of spinach—Flat leaf and Savoy or curly leaf spinach.  For fresh eating, harvest when young as they have more nutrients at that time.  Mature spinach is better for cooking. 

For a steady supply plant every 2 weeks until the temperature rises consistently above 70˚ (spring) then less than 75˚ (fall).   Bolting will occur with overly warm temperatures and inconsistent watering.

Choose an area that will receive some shade.  Spinach prefers fertile, well-drained soils rich in organic matter for best growth.

Before planting, loosen soil at least ten inches deep and incorporate 2-4 inches of well-composted organic matter and a high nitrogen, organic fertilizer (alfalfa, etc.). Till at least 6” deep, add good compost, Glen’s mix, Bone meal and Epsom salts.

Transplanting

Spinach can be transplanted when soil is about 40˚. Transplants provide an earlier harvest. Transplants should have 4-6 mature leaves and a well-developed root system before setting out. Generally, 5-6 weeks are required to grow transplants to this size.

Seed

Soak the seeds overnight to speed up germination.  Sow ½” deep in soil starting mix or direct seed in the garden.

Spinach seed can be sown after soils reach 40°F. Seeds germinate best at 55-65°F and require 7-10 days to emerge. Temperatures above 80°F reduce seed germination. Seeds should be planted ½ inch deep, 2 inches apart with 12 inches between rows. Thin when plants have 3-4 true leaves. 

As the plants grow, gradually thin them so the leaves of neighboring plants barely overlap. Dense rows will reduce weed pressure.  Plants removed at thinning can be eaten or transplanted to adjacent areas if some roots are maintained.

MULCHING

Light mulching will help suppress weeds, conserve soil moisture and keep the soil cool.

WATERING

Water spinach regularly. Water requirements depend on soil type and temperatures. Moisture fluctuations will cause leaves to become tough, slow leaf development and contribute to off flavors.

Keep the soil consistently and evenly moist.

Spinach is a heavy feeder of nitrogen.   You may use an organic fertilizer to supplement either as a side dressing or foliar spray every 2 weeks for best growth.

Keep the weeds out to avoid competition.

Spinach does not compete well with weeds. Weed control is particularly important during establishment. Cultivate shallowly and avoid root pruning to ensure uninterrupted growth.

Crop rotation and quick removal of infected plants will help control disease. For mildews, remove infected leaves and control with a spray of water and baking soda.

Aphids, Leaf Hopper, Leaf Miner, Spider Mites.
Floating row covers will effectively stop most of the insects that might chomp on your spinach.

The best time for picking is early morning because mineral content in the leaves in highest at that time.  Outer leaves can be removed to keep the plant producing or the whole plant can be removed.    

Individual spinach leaves may be picked any time before the flower stalk forms. Older leaves are often stripped off the plants first allowing the young leaves to continue to grow leaving the central rosette intact.  During long, warm spring days spinach tends to bolt.  Pull the plants when you notice them developing a tall central stem.

PRESERVING/STORING

Spinach can be stored in plastic bags in the refrigerator for up to 2 weeks.  It can be blanched and frozen, canned, or dried.