Developed by James Wong - If you want to add a bit of fire to liven up your salad this mixture of varieties of wild rocket, mizuna and spicy mustards will tingle your tastebuds. Sow: April-October. Harvest: April-November. Salad leaves are relatively expensive to buy yet are quick and easy to grow If you want to add a bit of fire to liven up your salad this mixture of varieties of wild rocket, mizuna and spicy mustards will tingle your tastebuds Sow April-October. Harvest April-November With their short shelf life and delicate constitution, salad leaves are some of the most expensive items on the fruit and veg aisle. Yet rather convieniently they are some of the quickest and easiest to grow.if you want to add a bit of fire to liven up your salad this mixture of varieties of wild rocket, mizuna and spicy mustards will tingle your tastebuds. Height 11-20cm.