Put inoculant next to the seed or the transplant root

Root fungi start when a living root sends a signal. Product scattered on dry topsoil, or mixed into a tray that never meets a root, does little.

Coat seed, dust or dip transplant roots, or put a small amount in the hole against the root ball. Nursery mixes that were sterilised or heavily fertilised often have no living partners left — add them at sowing, not after the plant is already stressed.

Read the label for storage and crop match. Heat in a shed can kill a packet before you open it.

Early contact with the root is the farm job. Compost heat usually kills these fungi, so do not expect compost alone to replace inoculation.

In this series

• Fungi need living roots, air, and moisture — a bag is not a soil
• Put inoculant next to the seed or the transplant root
• Too much phosphorus can turn the partnership off
• Host crops keep fungi; long brassica or fallow sequences starve them
• Tillage, compaction, and waterlogging break the network
• Match the fungus type to the plant — vegetables are not pines