Everything You Need to Know About Hydrangeas

Types of Hydrangeas: Which One Is Right for You?

There are so many types of hydrangeas. The right hydrangea for you comes down to choosing a type that will thrive in your climate and fit your space.

Let us look at the most popular varieties:

• The classic bigleaf hydrangea is probably the most well-known type with its big, fluffy flowers. With blue, pink, or white flowers, these hardy shrubs do best in shade and acidic soil. More alkaline soil gives you pink petals, while acidic conditions yield blue blossoms.
• Panicle hydrangeas, like “Limelight”, have cone-shaped flowers that go from green to white. They can handle more sun and warmer climates. These fast-growing hydrangeas make a great privacy hedge.
• Smooth hydrangeas are also sun-tolerant, with sturdy stems and serrated leaves. Their lacy white flowers turn pinkish in fall. “Annabelle” is a popular cultivar.
• The climbing hydrangea vine can reach up to 50 feet high. It produces fragrant white lacecap blooms in late spring. While slow growing, this hydrangea vine makes an elegant cover for fences or trellises.
• Dwarf hydrangeas, such as “Little Lime” or “Bobo”, are perfect for small spaces. They grow only 3 to 5 feet high but have the same bold blooms as their bigger cousins. Plant them in containers on your patio or at the front of a flower bed.

The Truth Behind Common Hydrangea Myths

Have you heard that hydrangeas only bloom on old wood or that their flower colour depends entirely on the soil pH? As Singapore’s award-winning florist, we are here to dispel those myths and give you the facts about hydrangeas.

• Myth: Hydrangeas only bloom on old wood. False.
  While some hydrangeas do bloom on old wood, many popular varieties like Endless Summer bloom on new wood and old wood. That means you will get flowers even after pruning.
• Myth: The soil pH solely determines flower color. Not quite.
  Soil pH does affect the colour of some hydrangea blooms, especially for varieties like macrophylla. However, for some hydrangeas, the flower colour is also determined by the plant’s genetics. Even if you alter the soil pH, the bloom colour may stay the same if it is in the plant’s DNA.
• Myth: Hydrangeas need lots of fertiliser. Only occasionally.
  Too much fertiliser can reduce blooming. During the growing season, liquid fertiliser once a month or biweekly at 1/2 of the recommended strength is plenty. Slow-release fertiliser in early spring is also a good option.

The Meaning Behind Hydrangea Colors

The colour of a hydrangea sometimes depends on the pH level of the soil it is planted in. The flowers can change colour over time as the soil pH changes. This is because hydrangeas absorb aluminium from the soil, which affects their petal colour.

• Blue flowers mean the soil is acidic, with a lower pH. Hydrangeas absorb aluminium in acidic soil, which turns the flowers blue. To get blue blooms, plant hydrangeas in acidic soil with a pH between 5 and 6.
• Pink flowers indicate alkaline soil with a higher pH. Without much available aluminium, the flowers turn pink. For pink blooms, aim for a soil pH between 6 and 7.
• Purple flowers happen when the soil is somewhere in the middle around neutral. At a pH of about 6.5, hydrangeas absorb some aluminium to produce purplish blooms.

The flower color can also be influenced by adding supplements to the soil like aluminium sulphate to lower the pH and make the blooms bluer. Garden lime will raise the pH and produce pinker flowers. With some testing and adjustments, you can get the colour you want!

Hydrangeas are nature’s pH testers. Their blossoms act as indicators of your garden’s soil acidity or alkalinity. Some gardeners plant hydrangeas of different colours together for a stunning display and as a simple way to monitor soil conditions.

The next time you see a hydrangea, know that its vibrant color is not just for show. It is a glimpse into the invisible chemistry happening in the earth below. A little botanical magic if you will.

Care for Your Hydrangeas to Make Them Happy and Healthy

• Watering: Give your hydrangeas about an inch of water per week. Stick your finger a few inches into the soil and if it feels dry, it is probably thirsty. This can be done with soaker hoses or low-pressure tubing with attached emitters.
• Fertilising: Feed your hydrangeas every few weeks during the growing season. Use a balanced fertiliser with equal parts nitrogen, phosphorus, and potassium. Follow the directions on the product packaging and dilute to 1/2 of the recommended strength. Fertiliser will fuel new growth and increase blooming. Stop feeding by late summer so your plant can prepare for winter.
• Pruning: The time of year you prune hydrangeas depends on the type. Bigleaf and oakleaf hydrangeas bloom on old wood, so prune them after flowering in summer. Panicle hydrangeas bloom on new wood, so prune them in late winter or early spring before new growth starts. Pruning hydrangeas involves removing dead or damaged branches and cutting the plant back to shape it. Never cut more than 1/3 of the branches at a time.
• Lighting: Most hydrangeas do best in dappled shade or morning sun. Too much intense sun can burn their leaves. If your hydrangea is not blooming well, it may need more sunlight. Move it to a spot with a few hours of direct sun per day and see if that helps boost flowering next season.

Following these guidelines and providing the proper amount of light, water, and nutrients while pruning judiciously will keep your hydrangeas looking their best and flowering abundantly. Pay close attention to your plant and adjust as needed based on the results you see.

Hydrangeas are quite easy to care for if you give them what they need – follow the tips in this article and you will be enjoying the beauty of hydrangeas for years to come. Spread the knowledge and help others nurture these wonderful flowers. Your garden and your neighbours will thank you!