How to grow hydrangeas – everything you need to know

How to grow hydrangeas – everything you need to know

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Hydrangeas are full of old-fashioned charm with the large flowerheads. These elegant and beautiful shrubs are easy to cultivate, they tolerate most soil, and most interesting of all is that the abundant blooms come in all colors ranging from clear blue to frosty white, all the way to vibrant pink, and you can even control to some degree the colors that you get on one plant. Growing hydrangeas is much simpler than other plants in the payoff is much bigger and brighter.

Types of Hydrangeas

Hydrangea macrophylla, colloquially referred to as bigleaf hydrangeas are the most common hydrangea. Also known as Mophead hydrangeas, they have puffy flowers in blue, pink, or purple. Lacecap hydrangeas have tiny flower buds in the center and larger flowers outside. Mountain hydrangeas, known as Hydrangea serrata, have flattened heads and the smaller flowers.

Smooth hydrangeas are a larger shrub otherwise known as Hydrangea arborescens. The flowers are green, but turn white. Their flowers take on a snowball shaped appearance.

Hydrangea paniculata, referred to as panicle hydrangeas, have long cone-shaped panicles and giant bulb shaped flowers that change from white to pink.

The oak leaf hydrangea, or Hydrangea quercifolia, has foliage similar to oak trees but the leaves will turn color in the fall and they are the only hydrangea which does this. They offer cone shaped flowers and a range of bright red, orange, and mahogany colored fall leaves.
The Hydrangea animola ssp. Petiolaris, or Climbing Hydrangea is a distinct type because it is a climber and will provide beautiful cover, shade, and decoration. However, it can take between three and four years to reach full growth at which point it produces white lacecap style flowers.

How to plant hydrangeas

Most hydrangea plants will thrive in rich, moist soil so when you start planting your hydrangeas it is important that you add compost to the soil to keep it as healthy as possible.

These plants prefer sunshine in the morning and shade in the afternoon but there are many varieties that will grow in partial shade especially the big leaf varieties with some even doing well in shadey areas all day.

  • When you are ready to plant, do so in the spring or the Fall.
  • Start by digging a hole as deep as the roots themselves but make the whole two or three times as wide as the root.
  • Place the plant inside the hole and then fill it half way with soil.
  • After that, water it and wait for the soil to drain.
  • Once that is done fill the rest of the hole with soil.
  • Finish it off by watering thoroughly.

If you are planting your hydrangeas in a garden, space them out approximately 3 to 10 feet apart.

If you are planting a Climbing Hydrangea these require a very strong and sturdy fence or wall to climb. As it gets larger and stronger the limbs will be heavier so make sure that you give it a location where it can grow securely.

How to cultivate from cuttings

Once you have thriving hydrangeas you can use the cuttings from an existing plant to grow more, saving you money and time going to be nursery or garden centre nearby. These plants root readily from cutting so once you have a well-established hydrangea, you want to look for a branch that has new growth on it but that new growth cannot yet have flowers. The stem will be a bit more flexible and the color will be much lighter.

  • Cut from the tip of the branch down word in length approximately four to five inches with a horizontal cut.
  • You can typically use the same branch to cut multiple sections but you have to make sure that there are at least three or four pairs of leaves on the cutting.
  • Trim off the lowest pair of leaves leaving just the top pair. Roots will grow out from these nodes so long as you do not damage the section of branch while you are removing the excess leaves.
  • It is in your best interest to get some type of rooting hormone and dusting the bottom of the stem with it. This will help protect against rot and encourage root growth.

Much the same as germinating other plants from seeds, you want to fill a pot with the potting mixture and place the section of branch all the way down until the top pair of leaves sticking out. Cover the pot with a plastic bag or with Saran Wrap and a rubber band around the top. The key is to make sure that whatever plastic you are using does not touch the leaves of the cutting. You can use things like Chopsticks to prop up the bag so that it doesn’t actually touch.

Place your pots in a place that is warm and sheltered from wind or direct sunlight. Make sure those soil remains moist and continue to check on the cuttings regularly. After approximately one month roots should be cultivated adequately enough to transfer to your garden. Some perfer to let the plant establish in the pot for 12months before repotting or planting out in spring.

How to keep hydrangeas healthy and happy

For the first year after you have planted your hydrangeas make sure they get plenty of water. If the soil is too dry you will notice the leaves start to wilt. If you live in an area with very rich soil you might not need to fertilize your hydrangeas. However, if you test your soil and it’s too sandy or too light you can always feed your plants in the late winter or the early spring with fertilizer to encourage growth. With fertilizer is important to read the instructions on the fertilizer you are using because too much will cause an excess of leafy growth on your plant but, at the expense of the beautiful blooms.

Once fall comes around, you want to cover your plants with things like straw, pine needles, or bark mulch. If possible, cover your entire plant by making some sort of cage from chicken wire and then loosely filling it with leaves. This will protect it from the cold winter and any permanent frost damage.

How to change the color of the blooms

You can change the color of the flowers you get from your hydrangeas but it will take weeks, if not months for the color correction to take place. Just be patient. On the hydrangea plants, you can change the color of the blooms from blue to pink or from pink to blue. It is easier to change blue flowers to a pink flower then it is to go from a pink flower to a blue flower. But this is not true of every variety. The mop heads and the lace caps can be changed in color but if you’re planting varieties other than these with beautiful white flowers, you won’t be able to make the change.

Acidic soil with a pH balance of 5.5 or less will produce blue flowers. Alkaline soil with a pH that is higher than 5.5 will produce pink flowers. So, you can use soil testing kits to verify the pH levels of your soil and add compound to alter the alkalinity or acidity in order to obtain the color you want.

How to properly prune

Most people plant big leaf varieties, the ones whose flower colors can be altered. The big leaf varieties and the oak leaf varieties should be pruned after the flowers have faded in the summer. You want to avoid pruning earlier than that because some flower buds can actually form at the end of summer and flower later in the season. When you do start to prune the plants you should only cut away dead wood in the early spring or fall.

The best way to encourage fullness and you plant is to cut one or two of the oldest stems all the way down to the base. If your plant has been neglected, if it was damaged during the last season, or it is getting older, you can prune the stems all the way down to the base to help rejuvenate it. Understand that doing so will have long-term benefits but you will lose any flowers for the upcoming season.

If you have other varieties you can prune them in the late winter, when the plant is dormant, before flower buds have formed.

Regardless of the variety in general it is best to only prune the dead branches and not to try and cut branches away to shape the bush.

Pest control

Hydrangeas are typically resistant to a great deal of the pests and diseases that affect other plants but you can still be on the lookout for leaf spots, powdery mildew, or slugs

Keeping cuts at home

Once your flowers have bloomed you can dry the flowers to create decorations in your home. To do this wait until the flowers have matured to such a point that they have a papery consistency. At that point cut the flower heads and remove the leaves from the stem. Hang the flowers upside down in a dark, dry, warm room and wait a few weeks for them to dry completely. It is best that you store them away from direct sunlight during this process. You can use diluted fabric dye to occasionally spritz the flowers once they have dried so as to enhance the color when they are decorating your home.

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