Garlic (Allium sativum) is an herb related to onion, leeks, and chives. It is commonly used for conditions related to the heart and blood system. Garlic produces a chemical called allicin. This is what seems to make garlic work for certain conditions. Allicin also makes garlic smell.Garlic bulbs prefer light, nutrient-rich soil and they don�t tolerate water-logging, so dig in plenty of organic matter such as compost, well-rotted manure or recycled green waste before planting.Carefully split the bulb into individual cloves.Plant each clove just below the surface of the soil (about 2.5cm deep) with the pointed end facing up. They should be 10-15cm apart.For several rows of garlic, space the rows roughly 30cm apart. This will give them plenty of space and help with weeding.Garlic needs a cold period to grow successfully but, during the winter, if you have heavy clay soil, start your cloves off in module trays. If the ground is too wet, your cloves could rot. Fill the tray with multi-purpose compost and place one clove 2.5cm deep in each module, covering the cloves with more compost afterwards. The trays should be kept in a sheltered position outdoors.