Which particular one are you asking about? "Dwarf bottlebrush" is not specific enough to give a useful answer.

If your minimum temperature is 15F you have a mild garden for this area, should be able to keep a variety of less hardy plants including bottlebrushes. If, on the other hand you have more usual conditions and the shrub you are asking about is said to be hardy to 15F you may see it fail after a comparatively short period.

It depends on how soon it gets that cold again on your particular site. The most mild, California-like places are at or near the beach.

Hi bboy,
Thank you for your quick answer. Well, I don't know exactly what it is (I forgot to look at their scientific name). I just saw a few pots at Mc---don, it lists as zone 8. I checked a few forums and some gardeners in zone 8 Texas reported that it came back after freezing. But they are drier. I guess I should just try it:-)

The way the USDA Hardiness Zones are repeatedly misunderstood Zone 8 on a nursery label could indicate plant goes south at 20F or not much lower. Since the parent species is not hardy here I assume the dwarf cultivar I've seen offered is not either. You can get hardier species from certain local growers or independent garden centers that patronize them. Shopping for your yard at hardware stores and big boxes has very definite limitations.

The Sunset climate zones given at the page linked to below contradict the hardiness zones shown. In our area (western WA) USDA 8 corresponds to Sunset 4 and 5. Sunset 8 does not come north of California.

Here is a link that might be useful: Probably What You Are Asking About

I have Callistemon citrinus but I uncertain it's the cultivar 'Little John." (Lost the tag.). Been in the ground about 5 years and still looking good in spite of the past 2 winters.

Mine is in light shade and went to 5 feet tall. But I've been pruning selectively to keep it just over 3 feet.

Thanks bboy, and for the link too. I think that's the plant. I entered my zip code in that website and it says I am in zone 7 but I don't remember having 10F during winter ever. I may be in denial but I always consider where I live a zone 8.

Thanks jean001, that's encouraging. Where you live is probably a little warmer than mine. But I think I will try it:-)

I live in Tacoma and had little luck. It was not so much the cold as sun issues and too much rain. However, in the right spot I bet it could flourish.

I had Callistemon citrinus (not a dwarf) planted close to the house. It survived two summers then succumbed to the cold winter before last. It's fun to have unusual plants but they are probably marginal here.

a dwarf would be easier to protect. you could make an insulated box to throw on top of it during cold spells.

For more information...

Here is a link that might be useful: Bottlebrush shrubs in Seattle

Thank you for all the good info. I really appreciate it.

I had a few Callistemon citrinus growing in the garden for a while, but the last one froze out in 2004 when the temperature dropped to about 22F in the most sheltered part of my garden where it was planted. I also don't have hope for any forms of C. viminalis which would include 'Little John'.

Last December was a good test for Callistemons when the temperature dropped to the range of 12-14F with nearly a week entirely below freezing early in the month. Undamaged by this event were C. sieberi (several forms), C. viridiflorus, Callistemon sp. aff salignus, and a few unknown dwarf ones that may be forms of, or closely related to, C. sieberi/pityoides. All of the above have cream or yellow flowers. The hardiest red-flowered species such as C. subulatus, and 'Woodlander's Hardy' mostly had minor to moderate damage, and though none were totally undamaged, I was impressed that these did pretty well overall. I would also place all forms of C. pallidus in this category. Everything else froze to the ground, including anything with purple flowers, and C. montanus, macropunctataus, rigidus, a pink form of C. sieberi, and several more unknown ones. Too bad. Callistemons are pretty good at growing back from the roots if they are cut to the ground, so perhaps they will return if summer ever arrives this year.

The true test of hardiness for trees and shrubs here is when we get single digits F., something that has happened more than once within my time. Some kinds may grow in the area for decades only to be wiped out when it gets that cold, providing the basis for stories about how there used to be a this or a that so many feet high at a place - but it's gone now.

Such specimens are a source of joy for zonal denialists but cannot accurately be used as a basis of claims of full hardiness. The risk of new plantings being lost to another killer winter becomes a problem when the unwary have been talked into planting kinds that aren't really "fully hardy here" - and would mind them being damaged or lost.

It could be 5 degrees F. again next winter or in 20 or 30 years.