Need suggestions for replacement trees in Landscaping

Hello fellow California Gardeners!

Can you help me find some alternate landscaping tree varieties for my SF Bay Area condo?

We have a courtyard at my condo complex that has some very lovely, tall, pink blossomed Locust trees. The trees are lovely. Unfortunately they are also very brittle, have aggressive roots and pervasive suckers. We've had a few limbs break off in the wind and damage part of a roof.

I'm guessing that the courtyard in question is about 6000 sq ft in size. It seems about the size of one of the older housing lots. The courtyard is rectangular shaped with a square green space/lawn area in the center and interlaced triangle shaped planting areas at either end. To Locust trees are located around the edge of the lawn area. We have smaller ornamental Pear trees and various shrubs alongside the buildings. Each building is three stories tall. The Locust trees currently provide a "meadow in the woods" effect for the greenspace, and some privacy screening for the second and third floor units. The HOA is planning to replace the Locust with Crabapple. Although I find the Crabapples very attractive in the right setting, I think the lower height and the shape of the Crabapple will drastically alter the visual aesthetics of this courtyard.

I was thinking of CA Native Large Leaf Maple, Liquidamber, Golden Chain or Ginko trees as possible replacements. I have seen that these trees can be trimmed/trained to be tall and somewhat slender (as opposed to a spreading canopy). Do any of you have any experience with these trees planted within 10 to 25 ft of a building? Comments? Suggestions?

All inputs welcome. Thanks!

I would suggest NOT putting Maple or Liquidamber Near a building or walkway! Aside from the leaf litter, Liquidamber drops large seedpods that are very dangerous to walk on , and many people are sensitive to the "felt" on the maple leaves. What ever you do, Don't put Queen palms in that type of location! If you're looking for fall color, you might consider Chinese Pistache. Check your Western Garden Book for ideas.
Carol

Thanks for the heads up on the Liquidamber seed pods.
Leaf litter is not an issue as we already have leaf litter from the Locust trees.

I've already been through the Sunset Western Garden Book and looked up the trees I mentioned. The book didn't discuss whether a tree might be suitable for in this setting.
We do have the option of moving the trees further into the courtyard and away from the walkways. We already have quite a few Japanese Maples in the landscaping as well.

Thanks for the suggestion of Chinese Pistache. I'll research it.

What about Acacia? Do these have any urban "secret issues"?

As a recently retired Caltrans landscape leadworker, I have dealt with many varieties of acacia (too many to keep track of), and most of the tree forms would do in your setting, I think. They are very undemanding trees (think surviving alongside the freeway).
Carol

Good to know. Thanks. The acacia blossoms are similar to the Locust blossoms, so perhaps this will be our solution.

mermaid, I know acacia blooms set off some folks' allergies something fierce, my DH's included.

Ginkos take absolutely FOREVER to grow.

I planted 2 liquidambars on purpose because I love the fall color, and they are quite "challenging" to clean up after. If I had it to do over again, I'd do Japanese maples.

I'm guessing JMs or crape myrtles would be too small to fit into your plans?

Of the list you have so far, I'd vote for the pistache. We have one as a city-planted street tree, and it's pretty well-behaved. Although they do drop dried berry clusters that can be pretty messy.....as Gilda used to say, "It's always SOMEthing!"

Does your DH react to all acacias or only certain varieties? I'm googling on allergies & trees. The existing Locust (Robinia) are in the same family as the acacia, so we may already have the allergy issues.

The challenge here is keeping similar visual aestethics in the courtyard. The Locust trees are taller than they are wide, and the foliage is not densely packed, so it provides for filtered sunlight rather than shade. The leaves have a soft flow and flutter in the breeze. A dense leaf structure that creates shade would impair the growth of the lawn and other plantings and make the courtyard dark.

We have crepe myrtles in an adjacent courtyard. They are not very tall and have a more dense, unbrella like canopy. Their shape would radically alter the appearance of the current greenspace and they would not be tall enough to offer any privacy screening to the second and third floor units.

It's really too bad that the Locust is so brittle and aggressive. They are lovely.

I'm trying to locate an example of the Chinese Pistache in a local planting so that I can get a feel for the apperance.

Cruising through the Western garden book for the umpteenth time this evening......
What are your thoughts on Jacarandas, Laburnums (Golden Chain tree) and Persian Parrotias?

We may need to pick a mixture of trees and replace the 12 Locusts with a handful of taller trees accompanied by some medium size ones.

While Jacarandas are probanly my favorite tree, I wouldn't have one in my yard. they are also very brittle, and with age, make a large root mound. The blossoms stain the walkways badly, but that's true of most flowering trees. I'm not familiar with the others you mentioned except in passing.
Carol

I'm not sure if there's a specific variety of acacia that sets of DH's (and others I know) allergies or not. Our neighbors had the one with the silvery leaves (loved it) and it drove him crazy. Other in the area have different varieties, and since the neighbor's tree has been gone, he still has issues during acacia blooming time, so it's not just that one variety that bothers him.

My friends who have a jacaranda as a street tree in Long Beach loathe it. If the petals land on their car, they etch the paint. If they get tracked into the house, they stain the carpet.

The silk tree would provide a similar shape to your locusts, but they're another TOTAL nightmare----always dropping something. Don't even think about them!

I don't recall anything positive or negative about laburnums from my nursery days, and I don't have any personal experience with them. I never heard of Persian Parrotias---they sound like they'd be exotic and noisy...LOL!

Thank you for the input.

Good to know that jaracarandas are also brittle and that the flowere stain.

We're not trying to avoid leaf litter or flower drop specifically, since we have quite a bit of that already from the Locust and we seem to do fine. The gardening service sweeps it up each week. Any tree litter is not there for long.

Is the silk tree you mentioned a mimosa?

There are over 100 different types of crabapple so you may want to check out exactly what kind of crabapple they are considering. It may very well meet the requirements.

I'd be careful about a chinese pistache. Nothing has a lovelier fall color but there are berries carried in the summer that have a pretty strong smell. It's a beautiful tree though and the right size. It's a tree I'd love to have although not on a patio
http://davesgarden.com/guides/pf/go/57160/

Ginko trees do take a long time to grow and mimosas do drop things all year long. How about a Japanese Maple. There are a number that will grow to your specs. You might ask on the Japanese Maple forum.

This is totally off the wall, but reading about the allergy, leaf drop, blossom drop, etc. problems makes me think of native trees we've used here - Catalina Ironwood or Lyonothamnus floribundus. Not sure if it's anywhere near the shape or type you are looking for, but we love them and they have none of the problems above. They do hold the old blossoms, so some people might think that's unattractive and it gets quite large, so might not fit in your situation.

Also, here is a link to a Plant Respecifier http://www.californianativeplants.com/index.php?option=com_content&view=article&id=69&Itemid=93
It has some ideas for native plants that can be used instead of non-natives. It might supply some ideas.

I am also very allergic to acacias so I'd vote against those too. I don't know what species I'm allergic to specifically because there are a few different types planted around here that all bloom around the same time and make me miserable! If you go with ginkgos, make sure you get boys and not girls--if there are any male trees in the area, the females will make horribly stinky little fruits that will drop everywhere and smell awful. I like Kathleen's idea about looking for natives--just make sure you research their water tolerance, since this is by a lawn area that may be too much water for some natives. Among non-natives one that might meet your criteria for being not too terribly wide is Grevillea robusta. I don't know how tall they get but the ones I've seen all seem pretty narrow. I like them for the orange toothbrush flowers. I don't have one in my yard so I can't speak to whether it's got issues with invasive roots, etc.

Forgot about the lawn - that can be an issue. Grass is so far from my thinking anymore, it's hard to imagine it! lol

Thank you doss & Kaper.
I'm trying to check out the exact type of Crabapple the HOA Board has in mind. Unfortunately they have not posted anything for the homeowners to consider. There was a brief mention in the minutes that they were going to request permits from the city to remove the existing Locust trees, since the large branches are breaking off. That was the only mention. I was expecting to see a proposed landscape design or list of proposed replacement trees so that homeowners could provide feedback. When I asked about this at the annual HOA meeting, the property manager told me that the Boards was in process of requesting the permits from the city to replace the Locust with shorter crabapples - without a homeowner review and feedback period! Needless to say, a group of us who live on this courtyard would like to have a chance to see the plans and have a say in the design. We chose to buy units on this courtyard because of the peaceful feel of the tall trees, filtered sunlight and overall ambiance. I'm trying to assist the process by offering some alternate tree and landscaping suggestions.

We have three greenspace courtyards at our complex. One courtyard is a manicured design with crepe myrtles ringing the grass areas and jungle gym designed as a children's play park. One courtyard has the pool, with another set of manicured myrtles, plus an nice wisteria over the trellis. The third courtyard, which is the one that fronts my unit, was designed to have a woodland park feel. The original plan called for acacia trees, but the developer switched to pink blossomed Black Locust at the time of actual planting (they were cheaper). We have Nandina Domestica (Heavenly Bamboo) shrubs growing beneath the Locust trees, with some carpet roses adjacent to them.

Thanks for the link to the Plant Respecifier.
California Native plants would be my first choice for all of our landscaping. That would allow us to cut back on the irrigation in many areas and would reduce some of the gardening labour. I doubt that we would get agreement on removing the lawn area in favour of a native ground cover.

Great food for thought!

Thanks.

Look like we were posting at the same time. I'm in agreement with you on the lawn but I need to be considerate of those that like to use the lawn area.

Good luck, GM. HOAs can be such a pain. It's so difficult to please everyone, but I would think they would at least ask for input and offer choices. Hope they find something to maintain the atmosphere and keep everyone healthy at the same time!

GM: yeah, silk tree and mimosa are the same. I think they're also pretty brittle, but I don't have personal experience. I was going to plant one when we moved in, and my neighbor talked me out of it---she had one at her old house and just hated it. Wish someone had talked me out of the liquadambars....sigh.

You have a challenging project on your hands!

If you are going to plant anything within 25' of your bldgs, make it a small tree rather than a large one.

I have one of the few varieties of small Liquidamber, a variegated type that grows to 25-30'. Liquidambers have aggressive surface roots and MUST be watered in slow and deep to avoid buckling pavement. They are deciduous and like the Chinese pistache, are one of the few trees that provides reliable fall color in our Bay Area autumn.

Chinese pistache are lovely trees, rather slow growing. The shape when younger tends to be wide rather than tall. One caution - because they have narrow, thin leaves, large accumulations of the dead leaves in the fall (such as one neighbor, who has 3 pistache in front of his house planted 3' apart in a row) make the sidewalk surprisingly slippery for a couple of weeks until they break down completely. Their autumn colors are the most brilliant of all our local trees.

I'd strongly suggest you check with your city and see what kind of street trees they recommend. These are usually reliable varieties that do well in our urban area and have been vetted as being the least troublesome when it comes to bark, pollen, leaf drop, etc. I think the Friends of the Urban Forest also have a website where you can plug in your parameters and get a list of suggested trees for short, medium, and tall varieties.

Don't forget about our wonderful local governments. I think you need a permit to remove your old tree http://sunnyvale.ca.gov/Departments/Community+Development/Planning+Division/Residential+Planning/Planning+-+Tree+Removal+Permits.htm
I found this really horrible video http://video.google.com/videoplay?docid=-4911769785150583157 but it would indicate that there is more specific information about trees that grow in your area.
I am just across the bay and some locals set up http://www.fremontica.com/roadside/ to show the local trees in situ. Go to the search and find a few trees of interest. Here is Chinese Pistach http://www.fremontica.com/roadside/usermap3.php?tree_map=1&asset_n=228 This site is a progession of a study the city did to locate historic trees in the area in 1974. At one time the site showed a picture of a big chipper/shredder for those trees of the original list that are now gone. Now they just show them lined out on the list.
I heartly agree NOT to use liquidamber. They are gorgeous, but were taking up the neighbors driveway and the seed pods can be really dangerous to slip on.
My daughter, in Fresno, has a variegated boxelder in her front yard that has turned into a very nice tree http://davesgarden.com/guides/pf/go/78078/ and my suit your needs. It is much smaller and slower growing than the standard boxelder that two of my neighbors have and that generate huge number of box elder bugs and messy leaves.

I have a variegated box elder, and I like it very much. However, it has to be monitored to make sure it doesn't revert to the standard green variety.

A whole bunch of variegated box elders were planted along 101 several years ago near the Blossom Hill exit, and they've all reverted to green. I occasionally get green branches on mine, and prune them off immediately so they don't take over the tree.

Thanks for the links PotEmUp.
The city requires a replanting plan when you apply for a permit to remove and old tree. This means you need to tell them what species of tree you are going to plant in its place before you can get a permit to remove the existing one. Overall this is a good policy because it keeps the city full of trees. The city did not have a list of "approved" trees to give me.

Thanks for the suggestion of the box elder. I'll look into it. I borrowed several native plant and low water plant garden books from the library this weekend.

Here is a photo of the existing trees. The five taller ones with a lighter trunk bark are the ones that have to come out.

This photo shows the splits in the trunk. One tree has blown over already and been removed.

Here is my current view from the living room.
There has already been some fall leaf drop. These trees have an open crown so that there is plenty of light even when in full leaf. They currently provide a nice privacy screen, noise buffer and provide a sense of open space.

I really love my flowering crabapple trees and if they have found one that is the right size I would be for it. The spring flowers are lovely, the berries in the winter and the foliage is lovely. Mine are small weeping cultivars because of room but people do comment on them especially when they are blooming. They are some of my very favorite trees. Forgive the stakes in the photo. They are for the lilies that bloom under the tree in the summer and I use them to make sure that no one steps on the lilies as they are coming up. I guess that they are worth it. :-)

doss, how often do you need to water in the summer? I've been looking at crapapple cultivars to see if I can find one that reachs 25-30 ft. So far they are all looking like they need a lot of water to look good.

Hmm, garden, in looking at your pics and your comments, several things come to mind for me. It's difficult for me to tell from either/both your pics and your description, but are there some trees in the same area right now which are shorter? Will they continue to grow taller? If not, do they provide something of a shorter-yet-adequate screen? They would still provide the noise buffer you mention and obviously contribute to your sense of open space.

If the aforementioned thoughts ring true, perhaps consider some of the smaller trees with open canopies, or year-round visual interest. Such an option simply requires opening your HOA's collective mind to some broader considerations. Redbuds come to mind to this novice gardener. Doubtless others with more experience could step in with other and perhaps better options, if you're open to such a shift.

Another consideration which I may have missed is some evergreens, pines, in particular, as they are often off the ground and less dense than others. They DO, however, have their drawback, like year-round needle drop and nothing growing underneath all those needles and sticky stuff.

Your environs are lovely with the Locusts. But those trunks are truly scary to behold!

Best wishes for a grand solution. You've received some awesome information from our brethren.

We have ornamental pear and hornbeam planted closer in to the buildings. Both of these are lovely, but have very dense canopies. Some of the ornamental pear are having large limbs breaking off.

Thanks again to everyone for your wonderful suggestions. It's been quite a foray in to learning about landscaping trees. I like the roadside arboretum approach. In some ways I've been doing an impromptu one as drive around looking at neighborhood trees.

At this point I'm inclined to suggest a mixture of a fell tall trees away from the buidings with some medium ones alongside. A mixture of native big leaf maple with some redbuds is the current top plan, but this may change. I have to present my proposal on Oct 22nd.

Once most trees are established (established is the operational word here) they can do with occasional deep waterings. I use a soaker hose or a root feeder. However, my crabapples are in irrigated areas so I really can't say how they would do with that watering schedule.

Having spent a goodly number of years in the "arts" community as a board member, occasionally an officer (president, even EEEEEEEK), I can identify with the community-based decision-making process. I can't even imagine doing it with people with whom I lived.

You've certainly done you homework, Garden_mermaid. Congratulations! Your proposal will doubtless generate dialogue which will keep your community happy. It's a lovely space and deserves your efforts.

Linda, aka Twincol

Thank you for the vote of confidence Twincol.
I was actually on the board of my HOA for four years. This is one reason I am perplexed by the current decisions. I know what's involved. I know that serving on the board can be a thankless job. I also know that you don't make major changes to the appearance of the property without sending advance notices to the property owners. Hopefully I'll get the full story of what is happening at the October meeting.