Root pruning is nothing new. It is done more commonly than we think about for many aggressive perennials like lily-of-the-Nile, that like to disperse their roots into areas where we want to grow more docile annual bedding plants or vegetables. We might do it halfway, or more, around a shrubby plant during spring or summer if we plant on digging and moving it the following autumn. For most small and low profile plants, root pruning is sort of tolerable. The plants that we do it to may not like it, but it is sometimes necessary, and better than not doing so.
Trees are not like most small and low profile plants. Most are very sensitive to root pruning when mature. They are not so proficient at replacing the portions of their root systems that they are deprived of. Large roots that get severed are very susceptible to decay, which slowly…

We may not get much foliar color in autumn here, but we get enough. Sweetgums do not need much cool weather to color well. They would probably have colored better and held their foliage a bit better if the weather got cooler faster, but we can not complain about what we got. Most of the crape myrtles are still completely green. Cottonwoods are defoliating, but without much color. Maples are rare here. The three best trees for color in autumn here are sweetgum, pistache and flowering pear. Of these, we happen to have several sweetgums here.
Sweetgum is not the sort of tree that I would recommend for home gardens. They are innately very likely to develop structural deficiency. By the time such problems are identified, they are difficult to correct without disfigurement. Aggressive roots are likely to displace pavement, and sometimes invade septic systems. Then there are all those…

There are many different types of horticulturists. We are all unique, both individually as well as collectively within our respective professional group classifications. For some of us, individuality interferes with conformity to the collective generalizations that are so commonly associated with our collective groups. For some of us, the stereotypes are a perfect fit.
‘Primarily’, I am a nurseryman. We are the intellectual ones. Well, at least we get most of the credit for being the intellectual ones. Most of us really are quite intellectual. Most of us are rather humble about it.
My excuse for nonconformity to the latter is that I am ‘secondarily’ an arborist. Arboriculture is something that I have never been able to get away from. I did an internship with the most excellent arborists in the entire universe in the summer of 1988. After all these years of mostly growing horticultural commodities, I still sometimes…

By ‘big trees’, I don’t mean the various ficus trees that can grow up to the ceiling, and be quite happy inside. I am referring to the shade trees that live out in the yard, or forest trees that live beyond that. They are outside for a reason . . . or actually, several reasons. They are too big to bring inside. They probably would not like the climate inside. No one wants to rake fallen autumn leaves inside. Well, you get the point.
Unfortunately, on rare occasion, big trees that are outside end up partly inside by falling or dropping limbs onto the homes that they provide shade for. Just like trees seem to fall onto certain types of cars more than others ( tonytomeo.com/2018/11/04/trees-hate-cars ), trees seem to fall onto certain types of homes more than others. The difference between the homes that trees seem to dislike and…

Fire has always been a part of life in most of California. That is why almost all native flora benefits from it, and has developed an efficient system and schedule for not only living with it, but exploiting it.
Within a few years after a fire, the pioneer species are the first to regenerate. They are aggressive, but short lived. Some are annuals. Others are trees that grow fast and then die out as the slower growing but longer lived trees dominate. Some of the longer lived trees might have been there all along, since they have developed ways of surviving fire.
Big valley oaks and coast live oaks that live out in the open away from other forest trees can survive for centuries because the grasses around them burn off fast and relatively harmlessly. Giant redwoods and some pines survive by standing high above the more combustible fuel below…

Junipers have a bad name. So do eucalypti. Too many of the wrong types were planted back at a time when they were too trendy. Those that were planted into inappropriate situations grew up to cause problems. The names of all junipers and eucalypti are now synonymous with those problems, even though there are many types of both genera that are quite practical for landscape purposes.
Get over it.
There are many junipers and eucalypti that are very good options for some landscape purposes. They need only minimal watering once established, and many will survive with none at all when mature. Some types of juniper grow as very low and very dense ground cover. With proper pruning, others can develop as exquisitely sculptural shrubbery or even small trees. (Just do NOT shear them!) Because of their very complaisant roots, some of the smaller eucalypti work very well as street trees.

Is it coming or going? Autumn that is. It normally gets here last. We are typically only beginning to see the first foliar color of autumn while other parts of America get their first snow. We typically get a few more tomatoes out of our vegetable gardens long after most everyone else has pulled out their frosted tomato plants.
Well, we still got it. Tomatoes that is. The plant that produces these bright orange cherry tomatoes is looking a bit tired and pale, but the tomatoes are as good as ever. It probably will not last until frost. The plant might get pulled out when the tomatoes run out. Without bloom, that could be pretty soon. Frost does not happen until well into winter. Regardless, tired tomato plants say that autumn is coming.
We got foliar color too. This Japanese maple turned this nice garnet red quite some time ago…

That is a myth. They do not hate all cars. They just hate particular cars.
I did an internship with arborists in the summer of 1988, and have never been able to get away from arboriculture. Even as a nurseryman, I still sometimes work for arborists, and inspect trees that they are concerned with. I have seen many of their subject trees that have fallen onto parked cars, homes and whatever trees fall onto. I have noticed particular patterns.
Trees are more careful with Buick, Oldsmobile, Pontiac, Chrysler, Volkswagen, Mercedes Benz, and Datsun or Nissan. I have seen them put considerable effort into avoiding these cars when dropping limbs or falling over. When I was in school in San Luis Obispo, I drove my neighbor’s 1969 Oldsmobile Cutlass out from under his Chinese elm that fell over it. The tree held itself up on limbs that landed on the opposite…

All Saints’ Day is November 1. As the name implies, it is a feast day that honors all Saints. It is one of the most important Holy Days of the Catholic Church. Yet, not many of us know about it.
We are much more familiar with the day before, which had been known as All Hollows’ Eve, and is now known simply as Halloween. Although some of the associated traditions are fun for children, Halloween has become an excuse for people to dress up in costumes, party, ruin perfectly good pumpkins, and behave stupidly. What an unsaintly way to celebrate, just prior to the day designated to honor all Saints!
Saint Patrick’s Day is no better. People dress up in green, party, exchange disposable potted shamrocks, and behave stupidly, all on a day that had been designated to honor a Saint whom they know very little about, and care even…

By modern standards, the public schools that I attended in the early 1970s would be considered to be bleak and primitive. The building were utilitarian and simple, from about twenty years earlier. The landscaping was comparably simple, with a big lawn and proportionately big shade trees. A screen of alternating Monterey pine and Monterey cypress was hedged on the southern half of the eastern boundary of the schoolyard. The only deviants to the simplicity were a few significantly older trees on the northern half of the eastern boundary of the school yard. There were two coastal redwoods, a Canary Island date palm, a cedar, and a spruce of some sort. They were all quite mature, and were likely remnants from an old farmhouse that was there before. Perhaps they wanted us to be aware that everything changes.
On the way to kindergarten, back when children were allowed to walk to…