How to Be a Gardener episode 6: However good a gardener you are, there are always outside agencies that do their best to prevent you succeeding. That’s life. Weeds will invade your beds and borders, pests will fly in to nibble leaves and suck sap, and diseases will spread death and destruction in their wake. But grow your plants well, and know what steps to take when you spot a weed, a pest or disease, and you can stay one step ahead.