You're welcome, Bob. Last fall my husband and I went to the Native Plant sale that was held at the SLO Botanical gardens and purchased two of the ceanothus impressus. I do remember the woman selling them to us saying that their ceanothus had been trained into that shape. Ceanothus have evolved to accept grazing from the deer, a little selective pruning (less than an inch in diameter) should be fine. Anyway, I've copied and pasted from their website: http://www.slobg.org/PlantArchive.asp Ceanothus 'El Dorado': Commonly known as the mountain lilac is in the family Rhamnaceae. Originally from California, it can be seen in bed 'A' in the Preview Garden. This evergreen shrub grows to 6 feet in height and width. It has deep blue flowers in the spring and summer and its leaves are dark green with splashes of yellow. The Mountain Lilac is used for a ground cover, on banks, as a background, an accent or a screen in large spaces. It produces leaves that attract caterpillars, pollen and nectar for bees and butterflies and seeds which attract birds. It must be planted in well drained soil and is native to rocky slopes. It should be seldom watered and water should be kept away from the stems. Some supplementary water is required during the summer but should be applied after the soil has dried. It prefers full sun or partial shade in inland areas. After the blooms have faded avoid cutting off limbs more than 1 inch in diameter. Pinch back the shoot tips during the growing season. The roots will rot if exposed to too much water. The Mountain Lilac is native to the chaparral plant community.

Ray Hartman is the longest blooming for me, blooming longer left than Julia Phelps and Dark Star. And ofcourse, the most tree-like. Mine only blooms a tiny bit in fall, but I have seen some around town that bloom sporadically in fall, maybe they get a lot of water? I too love ceanthus and got a little over eager and put in way too many of them. I ended up removing Tuxedo and Frosty Blue, only to make room for other plants. Frosty Blue got tree like very fast, and bloomed heavily, but I don't remember if it was noticeably longer blooming than the others.I also grew it at my previous house and was very pleased with it. I would recommend a variety of other plants, maybe some toyon and manzanitas which could complement the ceanothus so it isn't too monocromatic. And ceanothus do seem so boring at the end of summer and in fall, that is when I succumbed and pulled some out.

Ray Hartman's super-easy to grow as a tree. As you say, all you need to do is pick a strong leader and remove any competing stems as well as the lower side branches. Usually ceanothus is pruned after blooming (otherwise you'll cut off the buds). Even if you don't care about next year's bloom, now might not be the best time as pruning will cause it to put out new growth which might be harmed if you have any chilly weather--so I'd say wait for spring to be safe.

I planted two of that variety about 18 years ago and both are gone now. The first one went within the first 7 years and the last one declined over a longer period of time finally falling about two years ago. I live within 1/2 mile of the ocean, which I think is probably what did them in. They were easily trained into trees by cutting back the "weeping" foliage, but it was a constant chore to keep them upright. One of the best things about the them was that they afforded me the opportunity to observe a woodpecker up close quite a few times. The pattern of holes they made on the trunk and limbs was one of the most beautiful things I have seen. It really pained me to stuff those into my woodstove.