As the weather warms, spinach plants will bolt more quickly. Expect to stop sowing spinach seeds sometime in May or June, depending on your climate. You can extend the season slightly by planting in the shade of taller plants and keeping your spinach plants regularly watered.
Sow Giant Winter spinach seeds 1cm deep spacing plants about 30cm apart to allow room for growth. Sow a few spinach seeds weekly throughout the growing season to ensure a continuous supply of fresh spinach leaves. Sow spinach seeds directly where they are to grow as seedlings can be susceptible to transplant shock.
Over-wintering Spinach Plants: You can continue sowing spinach seeds late into the fall season. In warmer climates, you could quite possibly be harvesting well into winter. If the ground freezes before the plants mature, mulch them with hay and leave them be until the temperatures warm again in spring. Remove the mulch and the plants should resume growing, giving you an even earlier harvest.
In cooler regions of Australia sow Giant Winter spinach seeds from April to September. In temperate regions of Australia sow Giant Winter spinach seeds from March to May. This variety is unlikely to grow well in warmer areas of Australia.