Is heritage valley oak the same as live oak? Yours was great looking. So sad to lose it.

I love the Chinese Pistachio (Pistacia chinensis) for its fall color. looks, drought tolerance and size (maxes out at 50ft.). Zone 16 here also but little rainfall.

Alrhough there are areas where armillaria is more prevalent than others, It should be noted that it is ubiquitous in the environment. Healthy trees will fight it off, stressed trees will succomb. So don't be afraid to plant another oak. For a twist, try a cork oak.

The average urban tree nation-wide lasts 37 years. Think in these terms, not the 900 year span of a Costal Live Oak. Stay away from the ash. It is too fast-growing to keep it in bounds without severe trimming; all the problems if you do and all the problems if you don't. It is the favorite food for dry wood termites.

Add to your list Canary Island pine, California pepper, and peppermint camphor.

Your old tree looks like it was a Quercus Lobata, commonly called a Valley Oak, a deciduous tree. It was like most California native oaks susceptible to Armillaria, a root fungus. Summer time water encourages its growth, but even without any summer water, your oak could in time become infected. A garden planted oak watered from its youth, will usually resist the problem.The evergreen oak Quercus agrifolia is more resistant but not immune, and will not get as large. One hates to lose such a beautiful specimen such as yours, but it happens in nature with no asphalt of concrete anywhere near it. I also would take a good look at the Pistacia chenensis. Al

Please consider trees native to California! I'd second going for an oak. One reason urban trees have problems is because they're planted in with turf, which needs regular surface watering (to keep a tree healthy, it needs DEEP soaks spaced out by a couple weeks).

We personally LOVE the Western Sycamore. Looking at your photo, I think that'd look terrific on your street!

Platanus reacemos, California sycamore. Is an excellent looking tree. Keep in mind that in zones 21-23, it is quite allergenic due to the chronic anthracnose on the leaves. This is not so much of a problem in the hot dry summers of zones 18 and 19.

Average summer highs of 88 degrees will allow anthracnose. Average of 97 degrees will discourage it. I don't know the midway point.

I would go with another Oak. Valley Oak--maybe.

Cork Oaks are beautiful, that's a good suggestion, and fast for an Oak. The Island Oak, Quercus tomentella is a good one but I don't know how it would do in your zone. There's a gorgeous one doing beautifully at Santa Ana Botanical Garden in Claremont, I think that's Sunset 18 or 19.

Here is a link that might be useful: Valley Oak

I wouldn't plant any woody plant where there has been armillaria acting actively pathenogenically - you can't count on it not attacking anything except maybe yews and turf-grass. You can poke around in the soil and weed out the rhizomorphs, or maybe just dig out the entire planting space and replace with fresh soil. This could work as long as the infestation does not extend beyond the edges of the exposed soil area, so that it might come back in from the sides after planting.

English gardening references have for a long time said not to leave tree stumps in woodland plantings due to the problem of armillaria coming out of them and attacking new plantings. Specimens may be in place for many years, only to get taken out by the fungus at some point.

Catalpa trees do very well here in the Bay Area, and quickly develop an impressive character. Gingko biloba is another tree to plant for the ages.

We seem to have two divergent views. The first, posted by amazing_hedges (who is me) is that amillaria is always present in the environment and can be fought off by healthy plants. The second is by bboy that amillaria creates a dead zone into which no woody plant should be planted.

I am going to hold out that both views may have merit and also that I may be wrong. but I am going to hold to my original view and challence bboy.

He states that no woody plant should be planted. No tree, no shrub, no rose. For how long and for how far? In the stump area? In the drip area? in the neighbors' yards 60 feet away? For a quarter mile? If the area is limited, why not just apply a fungicide, after a time reintroduce micorrazae, and plant what one wishes?

What do we see in the forrest? Do we see expanding dead zones cause by amillaria or do we see individual trees infested with amillaria surrounded by healthy trees? How does our experience in the natural forest relate to our experience in the urban forest?

One key experience with amillaria in Southern California are the Blue Gum eucalyptus which look healthy one day and fall over the next. I have been called to clean up a half dozen of these in the past three decades. I have noticed that all of these had extensive rot at the bawho bothered to look could have noticed.

Indeed, the German physicist Clauss Mattock taught us that a tree rotted 70% hollow was just as strong as a solid tree, but that a tree rotted 90% hollow could not stand long.

All of these trees were planted in rows, standing next to trees that showed no signs of affect from amillaria.

I do not contest that amillaria can "come out" of a stump and infect other plants. All life forms have methods of propagation. Yet I do perceive amillaria as ubiquitous (always present) in the environment to attack weak plants and to digest dead plant matter. i do not see a need to declare dead zones around amillaria activity.

Thank you so much, everyone, for your responses here! Lots of great thoughtful feedback -- exactly what I was hoping for!

The old tree was indeed a valley oak -- its collar was buried about a foot below grade when the lot was created in the 1920s, so amillaria certainly wasn't the only factor that did it in -- just one of several challenges the tree was dealing with! The root zone stretches clear throughout our garden, as you might imagine with a tree that large, so whatever's in the roots is surely going to be there for a while.

We love the suggestion of a cork oak and have gone around to see a few larger examples to guesstimate what that'd look like. We'll check out the peppermint camphor and the Chinese pistache, and see if we can find a mature catalpa to look at. I like how fast the sycamore grows, but one of our nearby friends has one with anthracnose right now, so I'm a bit wary of that.

Does anyone have experience with the nyssa sylvatica/black gum/tupelo (we're looking at the Wildfire cultivar) OR any of the sorbus varieties (i.e. mountain ash)? Those are now also in the running (maybe?)

Seriously, a big thank you to everyone. This has been such an overwhelming process, so I'm so grateful for anybody taking the time to weigh in.

There are some great suggestions above! I am in a similar situation as you. We just had a large, old maple cut down due to disease and now our section of the street looks naked because now there's a gap in the line of maples.

I would add Araucaria bidwillii to the list. Those trees are so majestic. There are many old specimens throughout Fresno and they are beautiful to look at.

Also, I'd encourage you to go the San Francisco Botanical Garden to get an idea of what grows well there.