Last updated on July 18th, 2019
What growing conditions do hydrangeas need? They are fairly simple requirements. Hydrangeas are very old-fashioned flowers in terms of the charm they provide to any garden. This shrub offers beautiful flowers and is tolerant of almost any soil. The range of colors you have access to is vast. They are excellent options for a range of garden sites whether you want to plant them as a shrub in pots or as a hedge.
Hydrangeas thrive in rich and porous soil but that soil must remain moist. The hydrangeas prefer full sun in the morning with shade in the afternoon. This is particularly true for bigleaf hydrangeas which are the most common hydrangea seen in regular gardens. The reason for this is that the morning sun gives an ample light but the afternoon sun can cause the roots to dry out too quickly and burn the leaves so you want to make sure that the hydrangeas are protected against direct sunlight. It is best to plant these in spring or fall, and if you choose to plant in spring you might luck out and see the flowers blooming that summer but if you wait you’ll have to sit tight until next season.
When you plant them you should dig a hole as deep as the roots. When you look at the roots they’ll typically come in the shape of a ball so whatever size that ball is should be the same size as the hole into which you place the hydrangea. The hole should be three or four times as wide as that root ball.
When you are ready, place the plant in the hole and fill it halfway with soil. Water the plant at this point so that the roots remain moistened and have the opportunity to establish themselves. Once you have watered at the halfway point, add more soil to fill the hole. Once that is done water the plants again to properly hydrate the roots.
If you are planting more than one hydrangea be sure to give them adequate space. They might seem small now especially if you just purchased a younger plant but as they mature they will expand so you want to give them approximately 3 to 10 feet apart.
How to grow from cuttings
If you want to give your hydrangeas the best possible start, you can grow them from cuttings. This is very effective if you already have a plant in your garden that has done well. Hydrangeas are one of the few plants that grow very quickly from cuttings and make for an easy opportunity to propagate at home. In order to grow from cuttings you should do the following:
- Find a branch on a well-established hydrangea which could be your hydrangea or perhaps that of a neighbour so long as you have asked permission. Look for a branch that is a new branch, one that is grown this season but hasn’t yet flowered. The way to identify new growth is by looking at the color. New growth will be lighter in color compared to old-growth and the stems won’t be nearly as rigid.
- Start at the tip of the branch and move downward approximately 5 in. Make a horizontal cut. When you do this be sure that there are at least three or four pairs of leaves on that cutting.
- Remove all of the lowest pairs of leaves from the cutting, removing them as closely to the stem as you can. Roots will grow much more easily from these particular leaf nodes so if you can remove two or three sets you’ll be able to cultivate more roots. However, you want to make sure that there are at least two pairs of leaves at the tip.
- If the leaves on your cutting are very large you can cut them in half and this will prevent them from being so large that they hit the sides of whatever plastic container you have over the cutting.
- Dip the leafless end of the stem into a rooting hormone. This will help to expedite the growth.
- Prepare a pot or container with potting soil. Make a hole using a pen or pencil straight down into the soil and place the root in it. Water the new plant lightly to get rid of any air gaps that might exist around the stem.
- With this point, you want to cover it with a plastic bag or plastic covering of some point so that you can create an insulated unit. There are plenty of containers you can buy specifically for this purpose which have a plastic top that affixes over the plant. Whatever you do just make sure that the covering no matter its form does not come into contact with the leaves or the top of the root. Give it enough room so that the plant can grow.
- Place the pots in an area that’s warm but sheltered from any wind or direct sunlight.
- You should check on the cuttings every couple of days to make sure that the plant isn’t rotting or showing signs of mildew on top of the soil. Concurrently make sure that the top layer of soil doesn’t get too dry if it does water it again. Within a couple of weeks and no more than one month, you should have roots perfect for transplanting. You can check this by gently pulling on the cutting. If there is any resistance when you gently pull, it means the roots have formed.
Caring for your hydrangea
For the first year or two after you have planted your hydrangea, and during any seasons where you have a lot of drought in your area, make sure that you water your hydrangea thoroughly. If at any point you noticed that the leaves are wilting it is indicative of soil that is too dry.
If the soil is very rich where you live you won’t have to worry about fertilizing your hydrangea or adding any food what is soil is very sandy or very light you might have to add some fertilizer about once a year. If you choose to do this it’s recommended that you add the fertilizer at the end of winter the very beginning of spring, right before the plants need it most. There is a fine line between the appropriate amount of fertilizer in too much. Too much fertilizer will give you beautiful, leafy plants but the trade-off is that you won’t get as many flowers.
When fall comes around it is recommended that you cover your plants with about 18in worth of bark mulch, pine needles, leaves, or straw to protect them from the winter. If possible you want to cover the entire plant and make some sort of cage around it was something like chicken wire to keep the loosely fitting cover of bark mulch or pine needles. The key here is loosely fitting. If it’s too thick it’ll get wet and suffocate your plant so give it a bit of circulation.
Changing plant color
With some hydrangeas, it’s possible to change the color of the flowers. This is only possible with the big leaf hydrangeas, specifically mophead and Lacecap varieties. With these quintessential hydrangeas over the course of a few weeks, perhaps even a few months, you can change the color of your flowers from pink to blue or from blue to pink. When doing this, however, you should wait until your plants are at least 2 years old before you try to change the soil. If you plant a new hydrangea and then immediately change the soil to change the flower color, it might be too much of a shock.
Acidic soils with a pH that is 5.5 or less will produce blue flowers while soils that are alkaline with a pH level higher than 5.5 will produce pink flowers. A good way to know if you can change the color is to simply look at the flower color you have now. If you are unsure the variety you have, check the color of the flowers and if they are already some shade of pink or blue they can likely be changed but if they are a shade of white they won’t be changed. And if you purchase new hydrangeas from a nursery or garden store, they might have a particular blue or pink color but that is usually a reflection of the soil in which they were cultivated at that facility so when you bring them home they may not produce flowers that are the same color over the subsequent years simply because of the soil you have your home.
How to prune your hydrangeas
When it comes to pruning and deadheading your hydrangeas it is important to know which type of hydrangea you have so that you can prune at the appropriate time. There is no hydrangea that requires excessive pruning and that most you want to cut them back before winter. It’s important to prune branches or stems that are dead or sickly. You can also deadhead the flowers if you so choose by removing mature flowers in order to make room for new growth.
Pests and diseases
With hydrangeas, the most common pests and diseases include leaf spot which can be brought about by problems with water and soil. There is also a risk of powdery mildew when the plant doesn’t get enough air circulation and there’s too much water in the soil. Another risk is mold and aphids such as hydrangea scale so be cognizant of where you live and what issues you might face giving your soil environment and weather.
Storing dried flowers
If you have hydrangeas you can always cut and store the dry flowers. You can use these to make beautiful decorations around your house. Wait until the flowers have matured. Once you feel a paper consistency on the flowers you can cut the flower heads off of the plant. Remove any leaves from the stem and then hang the stem upside down in a dry, dark area. It should take a few weeks but once it is completely dry you should store it out of direct sunlight. When you are ready, use it as decorations to create a wreath or anywhere else around the house that might need beautiful dried flowers. If you want to change the color you can always spritz the flowers with diluted fabric dye to enhance the natural beauty.
Using your flowers in a bouquet
You can, of course, place freshly cut flowers throughout your house. Cut them when they have reached proper maturity and put the stems immediately into cold water so that the flowers don’t wilt. It is best to remove any lower leaves from the stems and then arrange the stems as you see fit. When you are done, place the bouquet in a cool spot in your house and check the water in your vase on a regular basis. You can always mist the blooms with the water so that they don’t wilt as much.
Varieties of hydrangeas
There are two main groups when it comes to the varieties of hydrangeas.
These are plants that produce flowers on new growth which is to say produce flowers on the stems from this year. The hydrangeas that fall into this category will form buds at the beginning of summer on new growth and then they will continue to produce flowers every year without much special care. The panicle hydrangea is the first type in this category and it can grow up to eight feet tall. The smooth hydrangea is the second type and this is known for producing tight, symmetrical flowers at the end of summer.
Group 2 are the plants that produce flowers on old growth, meaning they produce flowers on the stems from last year. These are a bit more challenging for gardeners who live in colder climates and are better for people who live in warmer areas. The most common of these include the Oakleaf hydrangea which provides beautiful fall colors for the foliage in tandem with the brightly colored flowers. The bigleaf hydrangeas are the quintessential hydrangeas that you find in most stores or floral arrangements. These are the flowers whose colors can be altered by soil. Mountain hydrangeas have similar shapes and sizes as other varieties but different colors. Climbing hydrangeas, as the name suggests, will climb which makes them ideal for things like trellises or walls.