The debate over hydrangeas pots or ground comes up with every new gardener. In-ground planting gives you stronger and larger plants with less work from you each week. But containers work well too when you pick compact types and commit to extra watering. Your choice depends on your space and how much care you want to give your plants each season.
The trend of container gardening hydrangea style draws in renters and patio gardeners. When I first tried this, I grew an oakleaf hydrangea in a large ceramic pot on my deck for three years. I kept the same variety in the ground nearby for comparison. By year three the ground plant stood 5 feet tall and 4 feet wide with dozens of flower panicles. The potted version reached about 3 feet tall with smaller leaves and half the blooms. Both stayed healthy, but the ground plant won by a wide margin.
Root space explains most of that gap for your plants. Your hydrangeas grow wide fibrous roots that spread far past the canopy in open ground. Those roots pull water and nutrients from a large soil volume around them. Container roots hit the pot wall and start circling. This limits their reach and the resources they can grab for your plant. Potted soil dries out faster and heats up more in the summer sun too. Your ground-planted roots never face those extra stresses.
If you want success planting hydrangeas in pots, start with the right variety and the right container for your space. Compact oakleaf types like Munchkin and Ruby Slippers stay smaller and adapt better to tight root space in a pot. Choose a container at least 18 to 24 inches wide and deep (45 to 60 centimeters) with drainage holes in the bottom. Use a potting mix made for acid-loving shrubs. Avoid garden soil because it compacts in pots and drains poorly for your roots.
Your care routine runs heavier with potted hydrangeas than with in-ground plants. You need to water your pots daily during summer because the small soil volume dries out fast in warm weather. Feed your plants with a slow-release fertilizer in early spring and again in midsummer for best results. Repot every 2 to 3 years to refresh your soil and give your roots more room before they get too crowded in the container.
Winter protection matters in colder zones for your potted plants. A pot sitting above ground exposes your roots to air temps that can freeze the soil solid inside the container. In zones 5 and 6 you should move your containers into an unheated garage. You can also wrap them with insulation to keep your roots safe. In-ground plants skip this problem because the earth around them acts as a natural buffer against hard freezes in your area.
Plant your hydrangeas in the ground whenever you have the space and plan to stay put in your home. Your shrub will grow bigger, bloom heavier, need less water, and survive winters on its own without your help. Choose containers when ground planting isn't an option for your situation. Treat the extra care routine as the price you pay for growing these beautiful shrubs in a limited space on your patio or deck.
Read the full article: Oakleaf Hydrangea Growing Guide
