Spring Cleaning in the Garden: How to Prune Shrubs

Globe Mallow (Sphaeralcea ambigua) before pruning

We had experienced a delightful spring with hot temperatures staying away for the most part. The weather has been so lovely that I’ve been spending a lot of time out in the garden. One garden task that has needed to get done is pruning back my winter/spring flowering shrubs.

What are winter/spring flowering shrubs you may ask? Well, they are those that flower primarily in late winter and on into spring. In the Southwest garden, they include cassia (Senna species), globe mallow (Sphaeralcea ambigua), and Valentine bush (Eremophila maculata). 

The time to do this varies depending on the plant and the region you live in, but generally, you want to prune them back once flowering has finished. 

I’ve decided to show you how I have pruned my cool-season shrubs and I find that using hedge trimmers make quick work of this job. Yes, I realize that I preach against using hedge trimmers for ‘poodling’ flowering shrubs into formal shapes, BUT they are very useful for corrective pruning for the health and beauty of your shrubs. I only use them ONCE a year.

Above, is a photo of my red globe mallow shrubs before I pruned them. They put on a beautiful show for several weeks, but have gone to seed, and they aren’t particularly attractive in this state. 

Newly pruned globe mallow shrubs

This is what they look like after pruning. As you can see, they have been pruned back severely, which is needed to keep them attractive and stimulate attractive, new growth. Don’t worry, while they may look rather ugly, in a few weeks; they will be fully leafed out.

Valentine bush before pruning

Here is one of my Valentine (Eremophila maculata ‘Valentine’) shrubs. This is one of my favorite plants, and it adds priceless winter color to my garden. One of the things that I love about it is that it needs pruning once a year when the flowers have begun to fade.

Valentine bush after pruning

I prune mine back to approximately 2 feet tall and wide, but you could prune it back even further. This pruning is necessary to ensure a good amount of blooms for next year. Don’t prune it after this as you will decrease a number of flowers that will form later.

Finally, it was time to tackle pruning my feathery cassia shrubs (Senna artemisoides). I love the golden yellow flowers that appear in winter and last into early spring. They add a lovely fragrance to the garden as well. However, once flowering has finished, they produce seed pods that will turn brown and ugly if not pruned.

I’ve created a video to show you how to prune these shrubs. Unlike the others, I only prune them back by 1/2 their size.

*As you can see in the video, my grandson, Eric was having fun helping out in the garden.

That is all the pruning that these shrubs will receive, which will keep them both attractive and healthy.

It’s worth noting that hedge trimmers aren’t a bad tool to use – rather, the problem is when they are used incorrectly to prune flowering shrubs excessively throughout the year.

I hope that this post is helpful to you as you maintain your shrubs. If you’d like to learn more about pruning shrubs in the desert garden, I invite you to learn more about my popular online pruning workshop. I’ve helped countless people just like you learn how to maintain beautiful, flowering shrubs with pruning twice a year or less! 

*What do you prune in mid-spring?

Ready to Prune? Here Are Common Pruning Terms Defined

Noelle Johnson, aka, 'AZ Plant Lady' is a author, horticulturist, and landscape consultant who helps people learn how to create, grow, and maintain beautiful desert gardens that thrive in a hot, dry climate. She does this through her consulting services, her online class Desert Gardening 101, and her monthly membership club, Through the Garden Gate. As she likes to tell desert-dwellers, "Gardening in the desert isn't hard, but it is different."