is our wisteria lost?

Asked July 24, 2018, 12:51 AM EDT

For 2 weeks our wisteria was not watered! All looks dead on this very mature wisteria. We are watering daily now and shoot are growing up but I’m not confident we have it back. Can be optimistic? Or do more to help the situation? We are in Portland, OR and this was a mo ago. Nancy

Clackamas County Oregon

4 Responses

A "very mature wisteria" should have a well-developed and extensive root system. In the northwest such a plant should be able to survive our dry months with only one or 2 deep irrigations.

The one big exception: A container-grown wisteria.

If a green shoot is coming from the roots, the vine is likely to soon burst out of the ground and regrow a sizeable vine more rapidly than you thought possible.

A mature wisteria should have a large root system. Such a root system only needs one deep irrigation every several months or so through the dry months.

Frequent sprinkles are worthless. "Deep" is the key.

To determine if that occurred when you water, do this easy test: An hour after you water, stick a flat-headed screwdriver into the soil. The screwdriver will easily penetrate moist soil; your goal is 8 to 10 inches.
If the screwdriver stops suddenly, it has hit a rock, a root, or dry soil, in which case, test again about 2 inches away.

Dear Jean,
Thank you for your very helpful response. I would like to add that the wisteria appears dead as it looks like it would in the fall when all green is gone. The green shoot that is the strongest is not from the main base of the plant it appears separate, so do do I cut back all the dead now and help direct the green vine(s) so it lay across the large large pergola? This such a strong focal point of our back yard. We are giving deep waterings religiously.
Thanks againn,

Wisteria is a well-known drought-tolerant pant. So, please stop with the deep watering.

If the main vine is dead, the only part that needs water is the green shoot. (Wisteria commonly send up new shoots at a distance even when the main vine is healthy.)

In this case, that surviving root may drown-- i.e.: die -- due to the actions of overly helpful gardeners.

Another caution: Do not fertilize the vine, or the live sprout.

"Watch-and-wait" may be the route to follow. Some apparently dead perennial plants surprise their owners by sprouting the following season.

Good luck.

Thank you