We’d like something this size.
I doubt we could get one like that at a nursery, but how big can we get?
Well, hard to tell how big that actually is. But I wouldn’t worry. The stuff grows fast. Buy some rosemary and watch it go.
We have a rosemary plant that is over two metres tall at the front of our place. I keep trimming it back savagely but it is pretty undeterred.
The thing grew from a seedling. (It was supposed to be lavender.) We had to dig the whole thing up for a plumbing job about three years ago. More than half its roots were removed and the amount above ground was just a small dry stick. Moreover, its previous water supply (leaking pipe) was now gone. Three years of absolute neglect and now that one plant has formed a hedge 6-8 foot wide and taller than me.
You know the plant in your pic is Ceanothus, right? 
I’ve seen some biggish rosemary bushes for sale in 3-5gal pots, and if you try a wholesale or landscaping nursery rather than the big box stores, you might have better luck. I’ve also seen big rosemary cut topiary style, which might be a bit pricier, but certainly would give you a head-start size-wise.
You could also post on Craigslist, I bet if you’re willing to do the labor, you’d be able to find plenty being ripped out that you could transplant. Rescue the rosemary!
Yes, it does grow pretty fast.
Rosemary and the PNW are naturals. We’ve had two plants out front for three years and they’re probably two feet high. They like full sun and don’t require a whole lot of water. They don’t last forever, though, and need to be cut back periodically.
Most nursery stock is fifteen gallons and under. Rosemary comes in different forms, some is nearly prostrate, others very upright & can get about 6’ tall (but fairly narrow). If you want a shrub that is as big as the ceanothus in the photo, I suggest you either buy a lot of upright-type rosemary and plant them close together, or select a kind of shrub that gets that big. Also if you want something you can shape like the plant in the photo, don’t try rosemary, it isn’t the best for shearing – it doesn’t sprout from old wood very well which is what you need in a sheared plant.
The reason why you don’t find shrubs for sale that big is that the root ball would weigh approximately a million pounds. And, the larger/older the shrub/tree, the more difficulty it has adjusting to a new space. Rosemary is one of the plants that transplants poorly at least where I live (northern CA). It grows fairly fast and gets woody and kinda ugly in about 8-10 years and I usually rip it out and plant a new one.
The two plants we actually planted in the ground are still alive. One sprig of the one we planted in a pot is trying to survive. Winter was harsh (for here) last year, with snow weighing down the plants. The plant that was the larger of the two when we planted them is now shorter and about half the girth of the other one, which is pretty much thriving.
Yesterday I saw something new: Our first rosemary flower. There’s only one, on the larger plant, and it’s tiny. But it’s there. Finally.
Buy a small plant, put it where you want it, and it will grow both quickly and massively.
Seriously, rosemary is an absurdly hardy plant. It actually grows wild in cracks in the sidewalk in downtown Austin, Texas! Even in the middle of the summer, when it’s 100+ degrees every day.
It’s one of the few plants even I can’t kill.
It grows like that in Austin because it’s a Mediterranean plant, so it thrives in hot sun and dry soil. Overwater it a few times in a moist climate, and then TRY and keep that sucker alive. Rosemary is very prone to root rot.
Interesting.
Two years ago, the largest plants we could find were maybe six inches tall when we bought them. So the ones planted in the yard did grow – just not as fast as we had hoped. The larger one is about knee-high now.
Interesting about the hot/dry growing conditions. The photo linked in the OP was quite a good-sized bush. Probably about three feet high and six feet wide. It was growing at a hotel in Friday Harbor, WA.
I’m curious about ‘how’ rosemary grows. My plants seem to be growing up, and the stalks seem to be filling out, but it appears that there are no new stalks. That is, the stalks that we had when we bought the little plants, minus the ones I cut off because they died or because I was cooking, seem to be the only ones there. Not seeing any new growth.
The plant shown in picture is not rosemary.
It smells like it, and the hotel staff told us it is.
This page (which probably answers my questions – I’ll have to read it) shows similar, though less manicured, plants to my first link. They say this plant was started from a three-inch pot and is now five feet high and 20 feet wide.
The original OP photo does not look anything like rosemary. Other posters seems to think it’s not as well. I’ve never seen one that looked like that. My neighbors had a large bush sized rosemary, but it’s gone now. A pity, because I borrowed leaves from it quite often.
Sorry, Johnny. araminty nailed it on the head. The photo of the plant in your original post is, indeed, ceanothus. Rosemary sends stems up from near ground level whereas ceanothus has a more stereotypical bush form with branches emerging for a main trunk or trunks.
If you’ll note in the last picture you posted, the flowers grow all along the upper portions of the stems. In the picture in your OP, the flowers grow in little pom-pom clusters. The flower shapes are totally different, as well. Here is a close-up of those on the ceanothus. Furthermore, as you can see, they have small, oval, glossy leaves. Those on the rosemary are dull and much narrower.
The one thing both plants have in common is that bees are madly attracted to their blue-purple flowers and if you like bees like I do, then you get a wonderful show on a nice sunny day. Rosemary makes a good honey, I know. I’m not too sure about ceanothus.
As for the plants you have, I’m wondering if they’re getting too much water, as purplehorseshoe suggested. You also get more below freezing weather than we do, which, scanning that article you linked to, could negatively affect rosemary.
Here, near the south end of Puget Sound, we have several large clusters growing in raised beds on the south side of our building. They get watered when it rains and, as far as I know, never get trimmed or fertilized. Yet they keep going like nothing short of a nuclear holocaust will stop them. I believe they were put in about five years ago.
Rosemary is one of those plants that root easily too. Just clip a sprig, remove some of the lower leaves and stick in some water for a few weeks. Or you could use rooting hormone if you wish. I’ve been meaning to do this as I want to try my hand at bansai and this would be an easy way to start.
I’ll have to take your word for it. It smelled like rosemary, I recall (remember this is a couple of years ago) there were leaves that looked like rosemary, and it may have even tasted like rosemary. (I think I tasted it, but I don’t remember.) And the staff said that’s what it was.
Be that as it may, the pic I linked to today does show large rosemary plants. That’s what I’d like ours to look like. What do I need to do to get them to grow that big? (Preferably without having to wait 20 years.)
The first picture is definitely ceanothus. I used to have a ceanothus in my front yard, so I know what it looks like. One giveaway is the oval leaves - rosemary has needle-like leaves. Also, ceanothus has its flowers in globular clusters, while rosemary has them in spikes.
Rosemary is a very drought-resistant plant. It’s happiest in a Mediterranean climate (not surprising, since that’s where it comes from). It’s also fire-resistant - if you hold a rosemary branch in an open flame, it will smoulder but not catch fire.
Another thing rosemary and at least some varieties of ceanothus have in common is tolerance of low-water conditions. We have both in the yard. OP photo is indeed ceanothus.
The photo is definitely ceanothus. Its superficial similarities to Rosemary (tough wiry growth, resinous, aromatic tissues) are in part adaptations to semi-arid and coastal environments; cistus, lavander and others also employ similar strategies to survive in low moisture conditions and deter animals from eating them.
Here’s a picture of rosemary