Growing a Hydrangea on the Patio

Container Culture

• 1

  Choose a species of hydrangea that is best suited to your climate for growing in a container. Consider bigleaf, oakleaf, arborescent and paniculata species for a variety of flower color and form, leaf shape, and seasonal bloom times. Contact your local cooperative extensive service for their suggestions if you’re unsure of recommended plants in your plant hardiness zone.

• 2

  Select a container that is large enough to hold your hydrangea, with room on both sides and at the bottom for roots to expand. Purchase as large a container as possible to allow for optimal root growth and moisture retention. Ensure that your container has a drainage hole at the bottom; if not, use a ceramic bit to drill one.

• 3

  Fill patio pots with bark-based loamy potting soil to a depth that allows hydrangea placement on top of the mix with the top of plant’s soil level a couple of inches below the rim of your pot. Backfill potting soil around sides of the hydrangea until it fills your container. Tamp slightly to press potting soil into container and add a little more, if needed, to raise soil level to the top of the plant’s soil level.

Plant Placement and Maintenance

• 4

  Provide light levels appropriate to the hydrangea species you choose. Place the patio pot in the morning sun and afternoon shade for most hydrangeas. Give paniculata hydrangeas more sunlight but still protect plants from harsh midafternoon sun.

• 5

  Water your hydrangea in the morning so that it has sufficient uptake time to hydrate itself before enduring heat stress later in the day. Direct a watering source at the base of your plant without using overhead irrigation, which can facilitate fungal diseases on wet foliage. Provide deep waterings instead of shallow sprinklings so that water flows from weep holes at the bottom of the container.

• 6

  Fertilize your hydrangea twice yearly -- once in spring as foliage buds open and once in late summer after blooming has ceased. Use a fertilizer packaged for acid-loving flowering plants. Follow label recommendations for container plants instead of landscape plants. Alternatively, blend your own organic fertilizer, using components and proportion recommendations from your local extension service.

• 7

  Prune your potted hydrangea to control growth, if desired. Cut back bigleaf hydrangeas, such as Nikko Blue and lacecaps, and oakleaf hydrangeas, such as Alice, no later than August so that next season’s blooming is unaffected. Cut back arborescent hydrangeas, such as Annabelle, and paniculata hydrangeas, such as Tardiva, in late winter or early spring to promote flowering on new wood.

Winter Protection

• 8

  Mulch container patio plants to conserve moisture, control splashback of possible soil-borne pathogens, suppress weeds and protect roots. Add a 2-inch layer of pine straw or pine bark mulch for acid-loving hydrangeas. Refresh mulch once a year as it decomposes.

• 9

  Leave containers outside during winter for hydrangeas to experience dormancy, which prompts flower bud formation. Insulate pots by wrapping them in burlap or canvas before the first hard freeze. Leave drainage holes unobstructed so that the hydrangea's roots do not rot. Stack straw bales around pots in very cold climates for further protection.

• 10

  Protect ceramic pots from cracking because of winter freezing and thawing by applying weatherproofing sealant. Use wooden planter boxes or lightweight molded terracotta-look pots instead of pottery containers for greater durability in harsh winter climates.