No garden’s complete without this old-fashioned favorite, and new varieties make hydrangeas easier than ever to grow.

Generally speaking, acidic soil, with a pH lower than 6.0, yields blue or lavender-blue hydrangea blooms. Alkaline soil, with a pH above 7.0, promotes pinks and reds. With a pH between 6 and 7, the blooms turn purple or bluish-pink.

To lower your pH, add garden sulfur or aluminum sulfate to your soil. To raise the pH, use ground lime. Follow the directions on the product you use, and retest your soil to make sure the pH is in the range you want.

You may have to reapply the garden sulfur or lime several times, and it may take several months for a change to occur. Don’t be disappointed if the color stays the same. Some selections resist changing, and white hydrangeas tend to remain white.

And don’t be surprised if the hydrangea you bought in a foil-wrapped pot changes color when you plant it outside. Remember: the pH of the soil determines the bloom color.

There is a wide variety of hydrangeas: standard size shrubs, dwarf varieties, or taller tree shapes. There are four distinct flower shapes: the lace cap, the panicle, the mophead, or the snowball. Some species bloom on old wood, others on new wood, and some varieties grow on both.

Dimensions: The size when mature differs according to the variety. Some areas small as 3 feet high and wide, while others can reach 15 feet high and 12 feet wide.

Exposure: Most hydrangeas flower better in the semi-shade, but some tolerate shade or full sun. The amount of sun that a hydrangea can accept depends on your location – further north, they can get more sun, while further south, they prefer only a few hours of sun in the morning.

Flowering: Hydrangeas usually flower in summer, some bloom earlier in the season and others later (and if you are lucky, perhaps even in autumn).

Colour: Most of them bloom in shades of blue, purple, or pink, but there are also white, green and even some red varieties. Many hydrangeas change color as they age. In addition, the flower color of some hydrangeas (mainly large-leaved hydrangeas or mountain hydrangeas) can be modified to be more blue, pink, or violet depending on soil composition and soil pH.

Typology: There are six main types of hydrangeas:

• Large-leaf hydrangea (Hydrangea macrophylla)
  Two types of inflorescences: ball or flat head
• Mountain hydrangea (Hydrangea serrata)
  Much less sensitive to late frosts
• Hydrangea paniculata
  Very easy to grow. With conical floral stems
• Oak-leaf hydrangea (Hydrangea quercifolia)
  Remains decorative all year round. Flaming colours in autumn.
• Climbing hydrangea (Hydrangea petiolaris)
  Climbing shape, ideal for shade.
• Virginia hydrangea (Hydrangea arborescens)
  A great classic, very easy to grow. Blossoms on the wood of the year.

What pot for my hydrangea?

Size

The first step is to choose the right container for your hydrangea.

Hydrangeas do not like too small containers because their roots develop quickly. In addition, small containers dry too quickly. We, therefore, recommend that you choose a pot with a diameter and depth of at least 40 to 60 cm.

Drainage

Make sure there are drainage holes in the bottom of your container. Indeed, the roots will rot if the soil is not sufficiently drained. Add a layer of clay beads, covered with a vegetable film, to facilitate drainage. Good drainage is the most critical step for healthy plants.

Soil

Get good quality soil. Mix a slow-release fertilizer.  Leave at least 5cm between the top of the soil and the edge of the pot, so that you can water without the water overflowing. Push the soil around the plant to remove air pockets and hold it firmly in the pot.

How To Care For Hydrangeas In Pots

Caring for potted hydrangea is quite simple and very similar to caring for hydrangeas in the garden. To thrive, hydrangeas need 3 essential things

• Well-drained soil
• Enough sunlight
• High humidity

Here are some tips to help your potted hydrangea grow and flower again every year:

• Exposure: most hydrangeas prefer the morning sun and afternoon shade. Outside, place your hydrangea in half-shade and away from the wind. Inside, choose a bright and cool spot. Note that some varieties may have other requirements. Check carefully the specificities of the variety you will choose. Be careful, too much sun can burn the flowers.
• Watering: it is generally recommended to water twice a week. But it all depends on the size of the pot and the plant, the weather conditions if the plant is outside. A sign that does not deceive: if the leaves hang, your hydrangea is thirsty. In this case, water immediately.
• Feeding: use a slow release generic fertilizer in early spring. A single annual application is sufficient. Too much fertilizer encourages rapid growth with few flowers. Never fertilize hydrangeas in late summer to avoid promoting growth at a time when the shrub must begin to prepare for winter.
• Maintenance: cut the flowers after flowering to promote continuous flowering and maintain the general appearance of the plant.
• Winter: hydrangea needs a cold period to flower again. If it stays in the garden, protect it with a winter veil and keep it away from cold winds..

When and how to repot your hydrangea?

To keep a potted plant healthy, it should be repotted to give it the space it needs to grow, especially in the case of larger plants such as hydrangeas. All varieties should be repotted every year or two and will give you signs when repotting becomes necessary.

Hydrangeas purchased in containers should be planted in the spring or fall. Make sure there is no risk of frost when you plant your hydrangeas outdoors.

The flowering of hydrangeas is particularly long and rewarding: 5 months. It is advisable to wait until the end of flowering, in autumn, to repot your hydrangea in a larger pot. At this point, you should ensure that you comply with the usual instructions for potting potted plants:

1. Soak the root ball in water at room temperature;
2. Gently air the roots and place the hydrangea in a larger pot;
3. Fill the pot with a layer of clay ball, vegetable film and compost, leaving a few centimetres to the edge of the pot;
4. Compact the soil, add slow-release fertilizer, water.