What Plant Food Can You Give to Runner Beans?

Organic Amendments

• As strange as it sounds, feeding your runner beans begins before you even plant them. You must prepare the soil for the runner beans with well-rotted organic soil amendments, such as compost or manure. These amendments are primarily intended to help the soil maintain moisture while draining off excess water, so that the bean plants are kept damp but not soaked. However, as the organic matter deteriorates, it will release nutrients such as nitrogen into the soil, feeding the runner beans through the plants' roots.

Fertilizer

• Runner bean plants are great at using their roots to draw nitrogen from the soil, especially if you have properly prepared your soil. Therefore, only feed your runner beans balanced or low-nitrogen plant food for fertilizer. Too much fertilizer will overwhelm the plants, leading to stunted growth or even the death of the plant. Feed the plants either liquid or granular plant food designed with higher amounts of potassium, phosphate or other nutrients that will feed the needs of the plant while avoiding overwhelming them with nitrogen.

Mulch

• Mulching around the plants is another way to contribute to their food intake. Spread a 2- to 3-inch layer of organic mulch around the base of the plants after you feed them in the spring. The mulch will help the soil retain moisture and will help slow the intake of the fertilizer or plant food, ensuring that the food continues to nourish the plants for the whole growing season. If you have accidentally overwhelmed your beans with nitrogen, mulching can help cut back on the damage by controlling the release of the nitrogen and keeping the soil moist so the beans don't suffer more stress than necessary.

Roots

• A final way to feed your runner bean plants involves using old or spent runner bean roots. Even after the runner bean plant is spent up, the roots contain a lot of the nitrogen and other nutrients that they absorbed during the life of the plant. Dig up the roots of plants you will no longer use and compost them, then spread them into the soil when you plant your new beans to add a boost of nutrition. Just make sure the bean roots you use don't come from plants that suffered from any diseases or infections, as the roots will spread these to the new plants as well. Never compost diseased plant matter.