Skip to Content

When To Prune Oakleaf Hydrangeas? (And How To Do It Right)

Oakleaf Hydrangeas have a special place in gardens, but many do not know how and when to prune these plants due to lack of information on the network. The most common method of pruning hydrangeas is deadheading (cutting off clusters of flowers), and also, there are other methods of pruning.

The best time for pruning (deadheading) Oakleaf hydrangeas as soon as the clusters of flowers start to fade. If you want to reduce the size of hydrangea or get the desired shape, you need to prune it in the spring. Pruning to ground level should be done in the spring or fall. Deadwood can be removed at any time of year.

When to deadhead hydrangeas?

You should follow the deadhead hydrangeas when the flowers begin to fade. Depending on the variety of flowering can occur at different times. By cutting off clusters of flowers, you free up space for new ones.

Starting in the fall, I do not recommend deadhead hydrangeas. It would be best if you left the old inflorescences until spring and only then cut them. This trick will help the plant to accumulate strength, and next year the flowers will be large and lush.

Use sharp, sterile scissors for pruning. It is better if they are long and thin, it will make accurate cuts.

Prune the clusters of flowers where they join the stem; if you cut them below this place, you can damage the buds from which new flowers will be formed, i.e., your hydrangeas will have fewer flowers.

When to prune for shape?

Very often, gardeners want to reduce their plants in size or give them some shape. However, hydrangeas bloom on old wood, so such pruning can reduce the number of flowers or inflorescences will not appear at all.

The best time to shorten the hydrangea or give it shape is spring when the plant has woken up from hibernation. This usually happens in March-April, depending on which Hardiness zone you are in.

The reason why spring is the best period is that during the growing season, the plant will heal wounds after pruning and have time to recover by next year.

You need to pay special attention to the pruning technique. If you want to slightly reduce the size of the plant or make it a large sphere, then cut the stems no more than a quarter or even less (1-2 leaf nodes from the top).

You should not damage the flower buds that are in the leaf nodes slightly above the middle of the stem length.

In this case, the hydrangea will bloom this year. However, the number of inflorescences may be less (it depends on how much you shorten the stems).

For this type of pruning, you will need quality pruning shears. Before pruning, sharpen them well and clean with antiseptic.

Trim the stems in the middle of the internode.

If you cut the hydrangea more than half, then most likely, you will lose this year’s flowering. The plant will grow and form flower buds that will bloom only next year. For the same reason, you should not shorten the hydrangeas in the fall because you will lose flowering next year.

When to cut to the ground level?

Another common practice is to cut the hydrangea to ground level. The reasons for completely pruning a hydrangea are different, so we will not talk about it now.

The best time to do this is spring. Make sure you do this before the leaves start to form. The beginning of March is the perfect period.

Unfortunately, as a result, you will lose this year’s flowering. The plant will grow new stems throughout the season and will bloom only next year.

The second favorable period is the beginning of autumn, but in this case, the hydrangea will not bloom next year. Prune the plant no earlier than early September and no later than late October.

In general, experienced gardeners do not recommend pruning hydrangea completely. However, if you still need to do it, make sure you do it right.

When pruning to full height, trim the stems 2 inches above the surface. This is necessary in order not to damage the crown because it can lead to its rot.

Use strong and high-quality bypass lopper. Always disinfect the tool before and after trimming.

When prune deadwood?

Throughout the year and especially in winter, the branches can be damaged or broken by the weight of snow or for some other reason.

Another common case is when young stems are damaged by disease. Usually, it occurs in the spring.

In all these cases, you will have to remove the deadwood so that the plant does not look ugly and to free up space for new growth.

Deadwood can be pruned at any time of the year except winter. This is due to the fact that almost all seasons, the wounds will heal, and the plant will be fine. However, in winter, the plant is dormant, and wounds can lead to wood rot.

You need to cut the deadwood completely, and you can even touch the living wood. Over time, the plant will heal wounds and recover.

Make cuts at an angle of 45 degrees to the stem. In this case, the water will drain from the wound and will not linger in it. As a result, you will avoid rotting in this place.

When working, use tools of the appropriate size. For larger branches, use a bypass lopper and use pruning shears for smaller ones.

And as in previous cases, sharpen and clean your tools before pruning.

Type of pruning When to prune
Deadheading After blooming
Pruning for shape Spring
Cut to the ground level Spring, Autumn
Removing deadwood In any time except winter

After pruning

After pruning, you need to take care of the plant properly, and this is no less important than the time of pruning.

The first thing you should do is spray the hydrangeas with an aqueous solution of the fungicide. This should be done for the reason that bacteria and spores of the fungus can enter the plant through the wounds. As a result, the hydrangea may get sick, or you may even lose it.

I recommend spraying several times after pruning with various fungicides at intervals of one week. Use different fungicides against the most common diseases.

The second thing to do is to water the plant properly. Hydrangeas are very like moisture because due to the large leaves, they evaporate a lot of water.

After you prune the hydrangeas, the amount of water they needed before pruning will decrease. However, new growth will require a lot of moisture.

Water the plants as often as needed. In the heat, it can even be daily watering. The soil around the bush should always be moist. The amount of water should be enough to saturate the plant, but you do not need to make a swamp.

To restore strength after shortening, the plant needs additional fertilization. Immediately after pruning, water the hydrangea with liquid fertilizer to give it a boost to grow.

The second type of fertilizer you need to apply is slow-release fertilizers. There are many good fertilizers on sale with the standard NPK formula.

For hydrangeas, I recommend using a fertilizer that contains more phosphorus and less nitrogen. In this case, the plants will have more lush flowers and less foliage.

In the spring, make a portion of granules that are recommended by the manufacturer, and that’s it. The fertilizer will do its job, and you will enjoy the beautiful flowers.

In the end, I want to recommend after pruning, be sure to spray the plants at least once with a systemic pesticide or Neem Oil. The fact is that after pruning, the wounds will release juice that will attract insects. As a result, plants can be damaged by pests.