When and how to prune a Bobo hydrangea to keep shrubs healthy and flowering at their best

The Bobo hydrangea is a compact panicle hydrangea that has all the glorious features that you want from a hydrangea but in a dwarf size. If you want to grow hydrangeas but do not have lots of space, then a Bobo hydrangea offers an excellent alternative to the traditional shrubs.

It is a very hardy compact shrub, down to US hardiness zone 3, and stuns with an abundance of large white flowers in summer. Due to its smaller stature, the pruning is very simple and helps keep the hydrangea healthy and putting on a fantastic show of blooms.

As with any hydrangea pruning, it is important to understand when and how to prune Bobo hydrangea correctly. If you are considering adding these unique shrubs to your backyard ideas, or are already benefiting from the joys they offer, we take a close look at Bobo hydrangea pruning.

Tools for pruning a Bobo hydrangea 

Only a few common cutting tools should be required for pruning. Before doing any pruning, it is important to make sure your garden tools are clean and sharp. 

Pruning shears and loppers that are sharp and sterilized will make clean cuts and not risk transferring diseases around the garden. 

Cutting with blunt and dirty tools is a pruning mistake that will make pruning harder and also jeopardize the hydrangea’s long-term health.

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When to prune a Bobo hydrangea

An important part of any hydrangea pruning is understanding the variety of hydrangea you have - as not all types are trimmed at the same time of year. Knowing the type helps you avoid making a hydrangea pruning mistake that can leave you without any blooms that year. 

Bobo hydrangeas are panicle hydrangeas, like the ever-popular, but a lot larger, Limelight hydrangea, and they flower on the new wood produced that year. Panicle hydrangeas can be pruned during their dormancy period to stimulate new growth that will carry that year’s flowers.

Lorraine Ballato, hydrangea expert and author of the book ‘Success with Hydrangeas’, says that means you can prune from late fall through to early spring. However, as for the ideal time, she recommends late winter or early spring, saying: ‘The best time to prune is when you see those buds swell and begin to open to little green stubs. Then it should be safe to cut away.’

The exact time your hydrangea starts to actively grow again each year will depend on your US hardiness zone, though Lorraine recommends judging when to prune the hydrangea by keeping a close eye on the plant and heading out to prune ‘as soon as you see it bud up’. Do not wait too long into spring to prune though, as then you do risk cutting off new growth that will be carrying the buds to produce the year’s flowers.

Lorraine Ballato

Lorraine Ballato is a hydrangea expert and the author of the international best-selling book 'Success with Hydrangeas', available at Amazon. She is also an in-demand speaker throughout the US and the resident hydrangea expert at the New York Botanical Garden.

How to prune a Bobo hydrangea

The compact Bobo hydrangea should not require lots of pruning each year and the scale of trimming you do may depend on the age of the shrub. Bobo hydrangeas tend to reach their full size within two or three years and trimming can keep it compact, healthy, and flowering profusely.

A Bobo hydrangea reaches just three feet in height and up to four feet in spread. Its compact nature means that you can gently trim it to shape the shrub, or it can tolerate harder pruning when required. 

‘How much to prune and how far down to go depends on the size of your plant and its age,’ says Lorraine Ballato. ‘If it is relatively young and small, you want to cut it back only a little. 

‘On the other hand, if it is over three years old and has gotten leggy, you can take out a third of it without worry. ‘

To prune your hydrangea, simply remove any stems that are dead, damaged, or diseased along with branches that are crossing or rubbing - as this rubbing can create entry points for hydrangea diseases. 

Following that, deadhead the hydrangea and then trim selected stems by pruning up to one-third of the branches. You can either cut back the tips of the branches to a bud or remove them down to just a few inches from the ground, depending on the shape you are aiming for.

FAQs

Can I prune a Bobo hydrangea in the fall? 

It is not recommended to prune in the fall. Lorraine Ballato, hydrangea expert, advises ‘hold off pruning’ in late fall and winter, even though the Bobo hydrangea will be dormant at that time. 

She says: ‘Winterkill will normally impact the plant so let Mother Nature do her work. If you cut prematurely and then winter does its thing, you may have a smaller plant at the start that still needs tidying up and that wouldn't give you much to work with.’

Any pruning in late summer or fall will result in the hydrangea putting out a flush of new growth that will not harden off in time for winter. Those new stems will be damaged by frosts and cold, making the shrub more susceptible to pests and diseases. 

Modern compact varieties of popular shrubs mean you can grow the likes of hydrangeas and roses in small backyards. For example, drift roses are a modern cross of miniature and ground-cover roses that grow to only two feet in height. Perfect for small gardens, or growing in containers, drift roses are easy to prune and maintain and open up opportunities for people with smaller spaces to enjoy the joys of growing roses at home.