Basic Pruning & Deadheading Techniques For Common California Native PlantsClick here to view a printable copy of this guide.
Preface to Pruning
Deadheading PerennialsDeadheading is the simple pruning of spent flower stalks and seed heads to clean up and rejuvenate the plant. While unnecessary for most shrubs, this treatment always benefits flowering perennials. (A perennial is a small flowering plant that does not get larger and ‘woody’ after a year or two, such as Columbine, Penstemon, Seaside Daisy, etc.
Typically deadheading is done shortly after the plant stops producing new flowers. With some natives, such as Penstemon and Monkeyflowers, removing spent blossoms will encourage the plant to re-bloom again the same season! Others such as Sages typically do not bloom again but look more attractive with this treatment.
Whatever the plant, the basic procedure involves finding a spent flower stalk on the plant, and clipping the stalk back to the first set of healthy leaves below the flower stalk.
An important note about deadheading - by cutting flower stalks as soon as they fade, you are preventing the plant from producing seed, and so its energy goes back into producing new growth, and sometimes new flowers.
Leave trimmings & seeds in your garden for wildlife. Many garden visitors of the non-human kind rely on seeds for their meals, though, so to strike a balance between a neat garden and a garden with high wildlife value, we don’t go overboard pruning back every spent blossom - we allow a fair amount of perennials in our garden to go to seed, then cut them back and place the seed-containing refuse in an area where birds and other animals congregate. This pile of branches and seeds is irresistible to quail and other small birds in late summer!
For many native perennials, and a few shrubs, a decent deadheading may be all the pruning they need! It is remarkable what a difference this simple technique makes in the attractiveness and longevity of some plants. Plants that have a woody base to them but produce lots of lush growth each season, such as Monkeyflowers and Penstemon seem to respond especially well to this technique.
We recommend deadheading all native perennials - either at the end of their blooming cycle or in early fall. A calendar for these isn’t really necessary - just watch the plants’ flowering cycle and they will tell you when it’s time. For perennials with particular requirements, a short table is below - otherwise follow instructions above. Shrubs that appreciate deadheading are included in the calendar at the end of this article.
Perennials with particular pruning requirements
ShearingThis is the type of pruning you should use least often. It essentially involves removing the outer layer of foliage, so that the foliage grows back denser. While appropriate for certain plants, many respond negatively to this treatment, especially if used as a long term strategy to keep a shrub small.
Plants you can Shear
Selective PruningOften the best technique to use, this method involves what it sounds like: carefully removing particular branches to achieve the shape you desire. This method can open up a shrub, allowing more light through, it can limit the size of the shrub and, done well, it works to highlight the shrub’s natural beauty. Most of the shrubs mentioned in our pruning calendar respond best to this technique.
CoppicingA somewhat radical pruning technique, coppicing involves cutting the plant down to the ground! This naturally is given serious thought before we go ahead with it. While a very rare occurrence when applied to the right species, this method can kill the plant. But if a shrub has gotten far too large for its area, or all the foliage and flowers have migrated to the upper third of the plant, it can work wonders. Also keep in mind that you are only pruning the upper half of the organism, not the roots, so it will grow back in a surprisingly short time. Most of the plants we have done this to are full grown again in two to three years, only they look way, way better.
Plants you can Coppice
Pruning to Control SizeOver the long term, pruning most native shrubs to limit their size does not work. The plants end up growing faster to compensate for their lost foliage, until they begin to lose vigor and you are left with a twiggy exterior. There are exceptions to this (see the section on Shearing for examples), but in general it is not a good strategy - far better to choose appropriate sized plants for a given area, or, when things get crowded, take a deep breath and choose which plants to take out entirely.
Having said that, when plants do need to be taken back a bit, clipping the plant back to the size you wish it to remain at is usually not the best strategy. Rather, find the branch that is growing too tall and trace it back into the interior of the shrub where it meets with a major branch. If you remove it there the shrub will have a bit of a hole in its canopy for a while but will usually fill in. The same method can be employed to maintain spreading shrubs’ width. Don’t shear it off at the edge of the sidewalk - lift up the branches till you find the lowest layer, and clip that back to the fork. Take a look, and remove another layer if you need to. This is better for the health of the plant and looks much more natural.
Grasses and FernsGrasses and ferns are very easy plants to maintain. Since they possess similar growth habits - outer foliage withering as new growth is produced from the center of the clump - pruning them is very similar. With the grasses, late summer or early fall is the best time of year to prune. Scissors often work better than pruners for this soft, flexible material.
The first step is to prune the ‘skirt’ of old foliage most grasses develop. Grab a clump of newer, taller foliage and lift it toward the center of the plant. Taking your scissors, reach in close to the core of the grass and cut away the bottom layer of foliage closest to the ground. Work your way around the grass in this fashion, clear the debris, and take a look. If you need to work around once more, do so. If the bulk of the grass has a lot of dead stems making it look ‘thatchy’, some additional work is needed.
You can safely prune grasses back to about 1/2-1/3 of their original size. The method for this is quite similar to removing the skirt - grab a clump of grass, twist a bit, and snip, working your way around the clump. It will look a bit odd for a few weeks, but will soon begin to push new growth. We do this to our larger grasses like Deer Grass and California Fescue only every 2-3 years, and they look much fresher as a result.
Ferns are even easier than the grasses - simply work your way around the plant, cutting back brown fronds as you go. Unless the plant has already produced a flush of new growth we don’t recommend removing green fronds, even if a bit tattered - you may want to prune once in Autumn, then again in late winter after the plant has produced a flush of new growth.
TreesThe art and science of pruning trees is a subject that many people literally get Master’s degrees in before attempting. It is really, really easy to permanently injure a tree, ruining its health and looks for life. It is also easy to hurt yourself! It is the one pruning job we hire outside experts to do here at the nursery. If you value your trees, and we’re sure you do, we suggest you do the same - it’s just too easy to cause irrevocable damage while trying to do something good for the tree.
Recommended ReadingA new book in our shop is "Care & Maintenance of Southern California Native Plant Gardens," by Bart O’Brien, Betsey Landis and Ellen Mackey. This bi-lingual book (Spanish/English) outlines gardening techniques for native plants with chapters on soil, watering, planting, pruning, pest & weed management. These techniques apply to Northern California gardens.
Shrub Pruning Calendar
Yerba Buena Nursery
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