Alice.W
Newly Registered
Posts: 7
Joined: Sun Mar 28, 2010 5:17 pm
Location: San Francisco Bay Area

Watering Wisteria tree

Hello!

I am new here and to gardening in general.

I have an old (~30-40 yrs) wisteria tree that blooms very nicely right now. My concern is how much should I water it during spring and summer. Where I live (San Francisco area), it doesn't rain at all from April till October, and every website I read suggest watering "only during prolonged dry spells". Well, 6 months sounds like a prolonged time to me, so I need a better advice, please. Last time it rained here was about 3 weeks ago and I haven't watered the tree since that.
The tree has a trunk about 6 inch in diameter.

Thanks!

cynthia_h
Super Green Thumb
Posts: 7501
Joined: Tue May 06, 2008 11:02 pm
Location: El Cerrito, CA

Sunset says that wisteria needs "little to moderate" water. This is their code for "almost no supplemental watering."

If you're in Zone 17, probably NO supp. watering. Zone 14 or 15, maybe once a month watering. Do you know your Sunset zone? Websites almost never allow for the variability of the multiple climates in the Bay Area: Brentwood is not Oakland is not San Francisco, in temperature, rainfall, wind, or any other climate indicator.

Cynthia H.
Sunset Zone 17, USDA Zone 9

Alice.W
Newly Registered
Posts: 7
Joined: Sun Mar 28, 2010 5:17 pm
Location: San Francisco Bay Area

I have no idea what zone I am in, but I am definitely buying the Sunset handbook today or tomorrow! Thanks for the tip!

oh yeah, and I live in west San Jose.

WatchMeShove
Senior Member
Posts: 122
Joined: Tue Jan 26, 2010 1:56 am
Location: Marin County, CA

wisteria

Alice, I live in novato (marin county), about 20 minutes from san fran, and about 1.5hrs. from san jose. You shouldn't ever need to water your wisteria. My parents have wisteria which does not have a 6 inch trunk but I've cut it to the ground a couple times and it always grows back. We have lived in the same house for over ten years and it has never been watered. Wisteria is a highly invasive species, I've actually cut off pieces of branch and stuck them in the ground and they have rooted and continued to grow. Wisteria is not actually a tree at all but rather a vine, however some wisteria has been trained to be tree-like. You will notice that all new growth will be green and look like a vine but they brown section of "bark" is at least one year old. In your case you would NEVER need to water your wisteria EVER unless it actually didn't rail AT ALL for over a year, which is very unlikely in our area. I am actually jealous because my wisteria isn't even close to flowering over here, probably about 2-4 weeks away. The fact that you have a 6 inch trunk and your wisteria is "tree-like" means it would never need water. You don't need to water any of the other trees in your yard, so why would you with wisteria?? The soil that is over a foot underground would never dry out even after two years of drought and I guarantee wisteria with a six inch trunk is multiple feet underground. I hope this helps. -Paul

Alice.W
Newly Registered
Posts: 7
Joined: Sun Mar 28, 2010 5:17 pm
Location: San Francisco Bay Area

Thanks, Paul!

I like "no watering" rule! Now, I am a bit scared about not watering any other tress... I have one quite mature orange tree, a little lemon tree, a young apple tree and a couple of other small trees (~ 4ft) I still need to identify :)

... but that a topic for another thread



Alice

cynthia_h
Super Green Thumb
Posts: 7501
Joined: Tue May 06, 2008 11:02 pm
Location: El Cerrito, CA

Paul and I are both in Sunset zone 17 (see map on p. 46 of the 2001 ed. of Sunset's Western Garden Book). My girlfriend, who lives 1 mile away from me and who has wisteria, never waters hers. She's in the Richmond Annex (if that is a helpful designation for you.)

If you're in west San Jose, you're most likely in zone 15, but could be in another zone; the maps aren't indexed for cities; they just show shadings, and the gardener looks at the shading vs. where s/he lives. My mother-in-law lives in zone 15, and I work in her yard/garden. It gets significantly warmer at her place than it does here.

Do you have any contact with the people who lived in the house before you moved in? They'd be the best source of information about this *specific* wisteria; Sunset is a good source of general information. Even so, it's not overdoing it to say that, if I could have only one gardening book, Sunset would be that book.

Good luck with the wisteria! :D

Cynthia

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