Seasonal Pruning Is Precisely That

Some trees get pruned after bloom.

Seasonal pruning is just as the terminology implies, seasonal. It might seem as if it all happens in winter. Most of it begins after cooling autumn weather initiates dormancy. Most of it is completed before warming spring weather stimulates vascular activity and resumption of growth. That is why most seasonal pruning is referred to simply as winter pruning. Winter really is best for most of it.

However, most is not all. Plants that are damaged by frost should not be pruned immediately. Because pruning removes insulating vegetation, and stimulates new growth that is more sensitive to frost, such pruning is delayed until after the threat of subsequent frost. Birches and perhaps maples are popularly pruned in late summer or autumn because they bleed so much if pruned in winter.

Flowering cherry, plum, peach, crabapple and quince do not need the same sort of pruning that their fruiting counterparts rely on. Their exquisite bloom is the priority, rather than fruit. Pruning prior to bloom could diminish their potential. They can instead be pruned immediately after bloom, as new growth is emerging, or later in summer after soft new growth has become a bit more resilient.

Lilac and forsythia should likewise be pruned after spring bloom, but more aggressively than the flowering fruitless ‘fruit’ trees. If not pruned enough, they will produce fewer canes through summer to bloom the following spring. Older and gnarlier canes should be cut to the ground to favor younger and less branched canes. Old Oregon grape and Heavenly bamboo canes can be culled too.

Redtwig dogwood and cultivars of willow that are pollarded or coppiced for their colorful twigs can be pruned later too. There is no need to deprive them of their primary assets prematurely. They should be pruned as winter ends though, before their buds start to pop. Pussy willow is an exception that gets harvested after buds have fuzzily popped, but before new growth begins to develop.

Evergreen plants can be pruned late in winter, just before new growth develops to replace what gets pruned away.

Weeping Bottlebrush

Weeping bottlebrush blooms whenever it likes.

It is no wonder that it takes many years to get to fifteen feet tall, and may never get more than twenty feet tall. Weeping bottlebrush, Callistemon viminalis, may grow less than a foot a year, but seems to hang downward two feet. Because the stems are sculptural, and the bark has an appealingly rough texture, most weeping bottlebrush trees are grown with multiple trunks. The brick red bottlebrush flowers that bloom sporadically at any time of the year are more abundant early in summer. Established plants bloom more colorfully with a bit of water, but can probably survive quite a while without it. The evergreen leaves are narrow and mostly less than three inches long. Weeping bottlebrush needs good sun exposure.

Knife-Leaf Wattle

This wattle sports texture with color.

Even without the bright yellow staminate flowers (fuzzy with prominent stamens) that bloom in late summer or autumn, the grayish foliage of knife-leaf wattle, Acacia cultriformis, is still striking. It contrasts nicely with dark green foliage of pines, redwood and ivy. What seems to be small triangular leaves are actually ‘phyllodes’, which are modified petioles (leaf stalks) of vestigial leaves. They are about half an inch to an inch long, and neatly arranged on stiff stems.

Mature trees do not get much more than ten feet tall, and grow slowly enough to be kept even shorter. They can tolerate a bit of shade from larger trees. However, they bloom more profusely with better exposure. If the pollen is not a problem, the flowers are nice for cutting. So is the foliage, which is complimentary to many other cut flowers. Like almost all acacias, knife-leaf acacia does not require much water once established.


P90728Without prior notice, I was informed on Friday morning of a workday on Saturday morning at Felton Presbyterian Church. That was yesterday. Since there was no time to get other chores done in advance, I was an hour late. Considering that we only work for four hours between eight and noon, one hour is rather significant. I felt compelled to attend regardless. A few friends who are parishioners of Felton Presbyterian Church appreciate it.
The difficulty of not attending is that there are several other volunteers who do attend, and they all have very different ideas, or no idea at all, about how to accomplish what needs to be done in the landscape. It is amazing how much damage can be done with a few light duty power tools and too much undirected ambition. Even when I am there, it is difficult to convince the others that I know more about horticulture than all of them combined.
For the past several years, I had been pruning a flowering crabapple tree to renovate the branch structure that was mutilated by someone with loppers and power hedge shears. Yes, hedge shears. I had pruned the tree for clearance above a parking lot on one side, and a patio on the other, but with low branches in between to partly obscure the view of parked cars from the patio. Bloom was spectacular, and not compromised by the pruning.
Then I missed a workday. Even though the flowering crabapple tree did not need to be pruned at that time, someone lopped away the lower limbs indiscriminately, and then sheared the top! There were mutilated stubs all over the new exterior of the canopy. Much of the blooming stems for the following season were removed. It was very disappointing to see all of my effort wasted so pointlessly. Now, I need to start the whole process over.
However, when I got there today, a planter box below the crabapple tree was being dismantled and removed. I could not work in the area, so must return to start the process of renovating the crabapple tree. Realistically, it should be done while the tree is dormant in winter, even if it compromises bloom for the following spring somewhat. The tree is so gnarly and congested now that it is unlikely that anyone would notice a few less blossoms.
As frustrating as it can be, we actually get quite a bit done. These lily-of-the-Nile in the picture above were one of our projects many years ago. They were recycled from a garden in Aptos from which they needed to be removed. We split, groomed and plugged them. Most were promptly removed and discarded by someone else who did not realize that we had just installed them. But hey, at least these few survived and continue to bloom.

Pink Trumpet Tree


This is why I do not often use pictures that my colleague, Brent Green, sends to me. He frequently tells me what I should feature in my gardening column, and sends me what he considers to be good pictures for such topics. This picture would have been good for writing about the sky over Los Angeles, or the neighbors’ driveway, since those are two of the most prominent features here. Where did all the smog go?

Chimneys in Los Angeles seem silly to me. Even if the weather got cool enough for a fire in a fireplace, there is no firewood to burn. The chimney to the far right certainly seems to be original to the house, but how did it survive all the earthquakes since the house was built, probably in the 1940s or 1950s? There have been a few moderate earthquakes since then.

Those signs that warn potential criminals of non-existent home security systems are even sillier, and just cluttering otherwise nice landscapes. There is nothing official looking about them. There are bins of them for sale in the local big box stores. Shouldn’t we all assume that since the home on the left is in Los Angeles, that it is outfitted with home security system that is more impressive than that silly, irrelevant and unwelcoming sign?

I would guess that what Brent really wanted to send a picture of was the big pink trumpet tree, Tabebuia heterophylla. After all, it does happen to be sort of in the middle of the picture. It really was spectacular while blooming late last winter. However, even if Brent had sent a good picture of it, I would not have featured it. Most of those who read my gardening column are not within regions where pink trumpet tree blooms like this.

Six on Saturday: Above And Below


Flowers are almost everywhere this time of year. Even some of the lawns are blooming with English daisy. Warm season annuals are starting to bloom nicely while a few cool season annuals that have not yet been replaced are still going. Although those that were established before this spring finished a while ago, a herd of daffodils that got planted very late last winter are just now finishing bloom. New flowers start bloom as old flowers fade.

I got these pictures of some of the more perishable blooms while I could, so some are already outdated. #1 was actually already fading before last Saturday, but I had other pictures to show at the time. #2 lasted only a few days because it is still recovering from getting relocated in the warmth of last spring, after it had already foliated. Of these only #3 and some of 4, 5 and 6 are in good bloom now, but they do happen to be quite spectacular.

Flowering cherry, star magnolia and flowering dogwood are small or mid sized trees that are above the low Pacific Coast iris below; hence ‘Above and Below’. (However, this particular star magnolia is only about four feet tall so far.) I can only identify the cultivar of the ‘Kwanzan’ flowering cherry. The rest are identified only by species.

Incidentally, there is far more above all of this that is not seen in these pictures. Almost all of the ‘biomass’ here is suspended by the grand but remarkably blandly blooming redwoods.

1. Prunus serrulata ‘Kwanzan’ – ‘Kwanzan’ flowering cherryP90427

2. Magnolia stellata – star magnoliaP90427+

3. Cornus florida – flowering dogwoodP90427++

4 + 5 + 6 Iris douglasiana – Pacific Coast irisP90427+++P90427++++P90427+++++

This is the link for Six on Saturday, for anyone else who would like to participate:

Six on Saturday: Spring Flowering Trees – With Problems


You probably do not notice the problems while distracted by the profuse bloom. That is just swell. It is gratifying that the trees that I work with are appealing to those who see them. Since I work with them, I notice their problems. I would have posted just close up pictures of the flowering cherries and flowering crabapples, but because they are blooming at different times this year, I got only these three.

1. The shade of the big redwood trees is a bit too dark for this flowering cherry tree. It is always this sparse. What is worse is that the upper layer of bloom is suspended on a single horizontal limb that extends from the right, out the backside, back in toward the center and off to the left as it is seen here in the picture. What looks like supporting limbs is actually trunks of birch trees in the background. I would prefer to cut the awkward limb off, but you can see how flat topped the remaining portion of the tree would be without it.P90413

2. This is the main reason the tree remains. These double white flowers are the whitest of the trees here.P90413+

3. My absence at a previous work day at the Presbyterian Church was the problem with this ‘Prairie Fire’ flowering crabapple. I had worked with this tree for a few years to thin out the thicket growth, and repair structural damage. Then, because I was not there, someone else pruned it indiscriminately with hedge shears and loppers! What a mess! It is best that you can not see the damage within the canopy. I don’t know why this was done. The tree only needed minor trimming for clearance above parked cars. After bloom, I will start the process of structural repair all over again.P90413++

4. These rosy pink flowers make it all worth it though.P90413+++

5. This flowering cherry actually looks better than I expected it to this year. I pruned out so much necrosis last years that I figured that the tree was deteriorating. I expected a bit more new necrosis to develop this years. As you can see, that did not happen so much. I am not disappointed. Actually, I am impressed that there is no necrosis worth noticing. The worst problem with the tree right now is that it is disfigured by the unexplained necrosis. Well, that will not prevent us from appreciating the bloom.P90413++++

6. This is the bloom close up. It is very similar to the other two old cherry trees that I will be cutting down this year. I wrote an article, and perhaps others, about them earlier.

This is the link for Six on Saturday, for anyone else who would like to participate:

The End Of The Cherry Blossom Festival

P90331After decades of spectacular spring bloom, this pair of flowering cherry trees in the picture above must be removed. They have been deteriorating for a very long time. Below the limber blooming branches of the tree on the right, there is not much more than a bulky rotten trunk, one rotting limb, and a short stub of a limb that was cut back to a bit of viable twiggy growth last year. The tree to the left has only a few more viable but rotten limbs.
Through this last winter, it was finally decided that we would allow them to bloom one last time, and then replace them with a new pair of trees of the same cultivar. I will cut them down myself. I do not want anyone else to perform this unpleasant task. Nor do I want such dignified and admired trees to be cut down by anyone else. Like I do for other prominent trees, I will write the obituary; a joint obituary for two who were always together.
Since the new trees will be of the same cultivar, they will bloom with the same profuse pale pink spring bloom, and will hopefully last for more than half a century like the originals did. Because the originals had been pruned back so severely as they deteriorated over the past many years, the new trees should grow to be as large within only a few years. They will not be the same though. There will be no adequate replacement for the originals.
The cherry blossoms below are of another pair of trees a bit farther up the road. They are not nearly as old, so could be there for a few more decades. There are a few others, of various ages and different cultivars, scattered about the neighborhood.P90331+P90331++

Pruning Late Might Be Justified

90313thumbThere may not be exceptions to every rule, but there are a few exceptions to the rule that winter is the best time for pruning. It is generally true that most plants are the most dormant through the coolest part of winter. It is also true that while they are the most dormant, most plants are less sensitive to pruning, as well as other horticultural techniques that interfere with their normal function.

However, certain ‘special’ plants get pruned later, either because it is healthier for them, or just because they are allowed to do what they do best in spring before getting deprived of some of what they need to do it with. Some get pruned rather soon after coming out of winter dormancy. Some should probably wait for their new spring growth to mature a bit. It is not as confusing as it sounds.

Evergreen plants that drop much of their older foliage through winter should probably be pruned late in winter or early in spring, essentially at the last minute, just before new foliage develops. If shorn early and deprived of outer foliage that should survive through winter, photinia looks scraggly as it continues to lose much of what had been inner foliage until new foliage develops in spring.

Red twig dogwood and some types of willows that are coppiced or pollarded to maximize production of their colorful twigs should be allowed to show off their colorful bark for as long as possible. Like photinia, they too can be pruned at the last minute, just before vascular activity resumes. However, red twig Japanese maple really should be pruned in winter so it does not bleed afterward.

Flowering cherry, plum, peach, crabapple and quince are grown for prolific but sterile bloom which is diminished by winter pruning. If they need it, they can instead be pruned after bloom, but before too much foliage develops, or after such foliage matures in late spring or early summer. They do not need to be pruned nearly as aggressively as fruiting trees that would otherwise produce too much burdensome fruit. Some may only need to have dead stems pruned out.

Six on Saturday: Another Day At The Office


There is no rush to leave the office and shop when the weather is cold and rainy. We have been getting quite a few of the inside chores done. When we do go out in the rain, I do not like to take the camera out from under my rain gear; so I do not take many pictures. Besides, since most of my work involves pruning right now, I have not been working much around what is blooming or other interesting subjects.

1. Sitka spruce brought back from near Smith River within their native range are now happily canned in the recovery nursery at our shop. They look as if they were grown here, or are on a bench in a production nursery. They will eventually go out into the landscapes.P90302

2. Staghorn fern that the same colleague with the Sitka spruce brought back from his grandparents’ home in Orange County are not so happy. They were desiccated on arrival. Now that they are getting much more rain then then need, they are just rotting. The specimen that is still attached to the plywood on the left is probably beyond salvage. The specimen that broke its wire and fell onto the deck to the right is only partially viable. The viable portion will probably be separated from most of the rotting necrotic portion when it is attached to a new slab.P90302+

3. Colorado blue spruce and a young coast live oak are adjacent to the deck where the Sitka spruce and staghorn fern reside. This is not a good picture, but shows how the young oak to the left is crowding the older spruce to the right. Their main trunks are only about two feet apart at grade. The spruce was planted back in the middle of the 1980s, and would be a more desirable tree, but is very distressed, and is not likely worthy of salvage. The native oak grew from seed within only the past several years, and is not particularly remarkable, but happens to be quite healthy and well structured. It is not easy to decide which tree to cut down. I sort of suspect that the oak will win, and the spruce will need to go. Those are cruddy box elders in the background.P90302++

4. Bucket of rain water is impressively full next to the spruce and oak . . . and other spruces and staghorn ferns. There is an open recycle bin nearby that is also full. It must have been somewhat dark rather early in the morning for the flash to operate when I took this picture. I do not know if it ruined my selfie or just made it more artistic.P90302+++

5. Wild plum is still blooming in some spots. These survived all the rain rather well by delaying their bloom somehow. It will be raining again by the time you see this after midnight on Saturday morning, so this bloom will not last long. There may be others that bloom even later though, and with one exception, the flowering cherries have not started their bloom yet. That darkness in the background is the trunk of a big redwood tree.P90302++++

6. Wild plum close up shows the detail of the blossoms, and the unfocused silhouette of the redwood trunk in the background.P90302+++++

This is the link for Six on Saturday, for anyone else who would like to participate: