Nitrogen is a major plant nutrient needed by all plants in relatively large amounts. Luckily, it is part of just about every plant food, so it is easy to prevent and to remedy by feeding.
Nitrogen determines plant growth and plays a major part in making leaves green. It is very soluble in the soil, so is easily lost or leached out of the soil through winter rains or regular watering.
Pale leaves and slow, spindly growth.
Treatment and control
Replace nitrogen in the soil by applying a balanced feed in spring to raise general nutrient levels. Liquid plant foods are fast-acting, so a good choice if nitrogen deficiency is noticed.
Mulching the soil will help maintain soil moisture levels, reduce leaching.