Growth habits and planting needs
Spinach is a fast growing leafy plant that is rich in iron and so a valuable vegetable to grow in home garden.
Select a position in the garden that receives full sun.
Spinach should be planted early in Autumn and grown when temperatures are cool as it is sensitive to heat and will bolt to seed if the temperature is too warm. In Sydney it is planted between March and May.
Spinach needs soil that is rich and well drained but constantly moist. It grows well in raised garden beds that increase drainage. As spinach has an extensive root system, large transpiration area through it s leaves and a rapid growth habit the need for plentiful consistent moisture is important to grow spinach well.
The following diagram shows the extensive root system of the mature spinach plant close to the surface and highlights the need for friable soil and moisture in the top 30 cm for proper root development.
Prepare the bed well by digging over the top 5 – 20 cms, removing clods to make the soil friable.
Dig through organic matter like well aged compost and well rotted chicken manure to enrich the soil for the plants to take up. Spinach needs to grow fast to be crisp and tender and nitrogen needs to be available to the roots for leaf and stem development.
Spinach should follow a legume crop in the crop rotation system to maximise the nitrogen fixed in the soils by the legumes.
Spinach tolerates slightly alkaline soils but is sensitive to acid soils. pH should be at least 6.0, but preferably in the 6.5 to 7.5 range. Test and amend the soil during bed preparation.
Soak seeds in water for 8-12 hours before sowing.
Sow the seeds 1.2 cm deep and 2.5 cm apart and cover lightly with soil. The seeds should germinate in 8-10 days. Seeds will not germinate if the soil is too warm
Spinach plants should germinate
When the plants develop at least 2 true leaves thin to strongest plants spacing them at 30-45 cm apart by clipping the excess seedlings to not disturb the fragile roots and use the clippings in salads.
When plants have 4 true leaves water with fish emulsion or compost tea. No extra nitrogen will be needed over the growing season if the garden bed has been properly prepared. Only amend the soil if the spinach plants show signs of leaf yellowing.
Mulch well around the plants to conserve moisture through evaporation and to suppress weeds.
Make succession plantings every week or two to maximise the crop harvest over the growing season.
Spinach will be mature in 35-45 days from planting and when the plant has developed its rosette of leaves. The younger the leaves the more tender.
To harvest the baby spinach leaves, cut using a pair of scissors and trim the outer leaves first . As you harvest work inwards leaving the central leaves to continue growing. Leaves can be picked this way and keep the plant growing.
Alternatively, cut the plant off at the base leaving the roots in and the plant will re sprout for a further but lesser harvest.
Consume spinach close to harvest to get the full nutrients that the plant can give and store in the refrigerator in plastic bags with moistened paper towel around the stems for 10 days.
When cooking or if eating fresh as baby spinach was in cold water thoroughly, rinsing a number of times to remove all the dirt from the leaves.