Zucchini Blackjack is probably the most prolific and famed Zucchini variety with very dark green fruit. Harvest regularly when about 15cm long to encourage higher yields. Keep well watered and feed regularly.
Sow 12mm deep, direct in final position. Sow 3 or 4 seeds in clumps, later thinning to the two strongest seedlings. Allow 100cm between rows and space plants 90cm apart. Keep the plants well watered and prepare the soil well by adding organic material and fertiliser.
Sow in spring and summer.