Pruning ilex - Ask Extension
When is the best time to prune an ilex shrub?
Knowledgebase
Pruning ilex #782611
Asked February 25, 2022, 11:30 AM EST
When is the best time to prune an ilex shrub?
Carroll County Maryland
Expert Response
Hollies (Ilex) are best pruned between late winter and early spring, roughly February into March. Deciduous hollies (like Winterberry) should be trimmed prior to the end of April in order to not interfere with flowering and berry production. Although early-season trimming for evergreen hollies can reduce berry production because it removes some flower buds, unless pruning is extensive, some berries will probably still form later that season on uncut twigs. You can also shear evergreen hollies lightly around mid-season (early to midsummer) if a touch-up shaping is desired. Overall, though, it's better for the health of the plant to minimize trimming and to not shear growth into a dense outer layer of foliage. In that case, if you need to remove errant growth creating an unappealing shape, just trim back those individual branches instead.
Miri
Miri
Miri,
Does late winter also apply to inkberries (ilex glabra)? We have a couple that are very overgrown and are hoping to get them down to a proper size.
Thanks for your help.
Beverly
On 02/25/2022 3:32 PM Ask Extension <<personal data hidden>> wrote:
Hello Beverly,
Yes, you can trim Inkberry around now, though waiting until sometime in March may be a bit safer in terms of our erratic weather. One reason trimming just before the growing season is suggested is so that new growth quickly covers-up the pruning cuts, but this is mainly for aesthetics; it might benefit the speed of "healing" for the cut stems too, but we do not know to what extent in this case.
The preferred way to reduce size on evergreen shrubs is to thin them over the course of a few years rather than a single pruning event. In doing so, some stems are reduced in height each year, allowing new growth to start filling-in in contrast to removing a greater proportion of foliage all at once. Inkberry does not grow as densely as some of the popular non-native hollies, even when new growth is stimulated by pruning, so drastic trimming doesn't always result in a denser plant as it regrows. If you do not want to stretch the thinning process over a couple of years, your best bet for promoting as dense a regrowth as possible is to stagger your cut branch tips to different heights, rather than an even, manicured look achieved by shearing. This way, when the foliage regrows, it will do so at slightly different heights, allowing more light to reach the interior of the branches to discourage excessive leaf shed. In contrast, if sheared instead, all of the new foliage emerges at about the same level, creating a shell of foliage that blocks more light from the interior and accelerating inner leaf shed.
Worst-case, if you find that over the next year or two the plants aren't recuperating well or are remaining too sparse in their lower limbs, you can replace them with an Inkberry variety better suited to the limited space. There are a couple of dwarf cultivars of Inkberry that could be a better fit, though they will mature more slowly than taller growers.
Miri
Yes, you can trim Inkberry around now, though waiting until sometime in March may be a bit safer in terms of our erratic weather. One reason trimming just before the growing season is suggested is so that new growth quickly covers-up the pruning cuts, but this is mainly for aesthetics; it might benefit the speed of "healing" for the cut stems too, but we do not know to what extent in this case.
The preferred way to reduce size on evergreen shrubs is to thin them over the course of a few years rather than a single pruning event. In doing so, some stems are reduced in height each year, allowing new growth to start filling-in in contrast to removing a greater proportion of foliage all at once. Inkberry does not grow as densely as some of the popular non-native hollies, even when new growth is stimulated by pruning, so drastic trimming doesn't always result in a denser plant as it regrows. If you do not want to stretch the thinning process over a couple of years, your best bet for promoting as dense a regrowth as possible is to stagger your cut branch tips to different heights, rather than an even, manicured look achieved by shearing. This way, when the foliage regrows, it will do so at slightly different heights, allowing more light to reach the interior of the branches to discourage excessive leaf shed. In contrast, if sheared instead, all of the new foliage emerges at about the same level, creating a shell of foliage that blocks more light from the interior and accelerating inner leaf shed.
Worst-case, if you find that over the next year or two the plants aren't recuperating well or are remaining too sparse in their lower limbs, you can replace them with an Inkberry variety better suited to the limited space. There are a couple of dwarf cultivars of Inkberry that could be a better fit, though they will mature more slowly than taller growers.
Miri
