How to Care for a Cardinal Hydrangea

The cardinal red hydrangea, or cardinal mop-head hydrangea, is a crimson-colored variety of the hydrangea garden flower. Caring for a red hydrangea doesn't differ too much from caring for other hydrangea plants; it is an easy flower to grow and maintain, even for beginners. Paying extra attention to the care of your cardinal red hydrangea gives it the ability to produce vibrant, bold colors that accent your home landscape.

• 1

  Pack about an inch-thick layer of peat moss over the topsoil in which the hydrangea plant is established. Do this whether the plant is rooted in the ground or in a planter. Peat moss retains moisture, of which the hydrangea plant needs plenty.

• 2

  Keep the cardinal hydrangea plant in partial to full shade. It can tolerate direct sunlight in temperate climates as long as it has moist soil and is fertilized.

• 3

  Apply an acidic commercial fertilizer occasionally to supplement the growth of the cardinal hydrangea. Like other hydrangea plants, the cardinal mop head prefers acidic, moist soil. Keep the fertilizers from coming into contact with the stems, roots or foliage of the plants by sprinkling small amounts on top of the peat moss. Direct contact with acidic fertilizers can "burn" the plant and kill it. Water the peat moss liberally to dissolve granular acidic fertilizers so the soil can soak it up and benefit from its nutrients.

• 4

  Dust the foliage of your cardinal red hydrangeas with borax lightly. This keeps pests from munching on the attractive green leaves. Aphids are common hydrangea pests, and the borax will keep them away without destroying the plant.

• 5

  Administer long drinks of water once a week to the hydrangea. If you have any powdered or granular plant foods such as color boosters, sprinkle them on the moss as you would use fertilizer before watering.