Question
QUESTION: Hi Kathleen,  I live in Northern Nevada and recently purchased a 19" Wisteria vine through the mail from a reputable nursery.  I transplanted it to a large pot.  It was out doors in full sun for 2 days.  Suddenly the leaves on the bottom of the stem turned dry and died.  I have lost a couple more leaves since then.  Please help me save my little vine by suggesting what may be wrong.  It is planted in potting soil and is receiving regular waterings. The weather has been in the 70's and low 80's and gets down to the mid 40's at night.  Thank you for your kind attention to my question.

ANSWER: Hi Gail-
Congrats on buying one of my favorite flowering vines.  A lot of people shy away from Wisteria, as it can sometimes be regarded as invasive -- one of those "Look out, Martha, here it comes again!" kind of plants.  But they are so rewarding, if a bit finicky.  First of all, you really need to plant Wisteria in the ground.  It won't mind being in a pot for a season or two, but it really wants to be in the ground if you want it to bloom reliably, and especially because its branches/foliage will need to be trained on something sturdy like a wall, fence, or trellis.  Second, there are a couple of things that could be causing the leaves to yellow.  The most obvious one is transplant shock.  This is normal when you bring a plant home from the nursery, especially if the light/water/temp conditions at the nursery vary significantly from conditions at your house. Another reason could involve drainage. Does your pot drain easily?  If the roots stay too saturated, that could cause the leaves to yellow.  A third reason could be a fungal infection.  I rather doubt that this is a problem, but you never know.  Are there spots on the leaves that have turned yellow?  A fungicide spray might not hurt.  Finally, aphids love Wisteria and when they feed on leaves they literally suck the sap right out!  Again, I doubt that aphids are the problem with such a new plant, but you might want to check the undersides of the leaves with a magnifying glass to see if you spot any tiny white critters.  If so, a horticultural oil will do the trick, provided you don't apply it when daytime temps are above 85 or 90.  You won't see any blooms on your wisteria for a few years; this is their normal growth habit, and wisteria must be pruned in very specific ways for optimum blooming; check the web for pruning tips.  But patience will be rewarded.  Please let me know how things go; if watchful waiting doesn't work and you are confident about drainage, then check the fungus/insect possibilities.  Good luck!

---------- FOLLOW-UP ----------

QUESTION: Hi Kathleen,  Thank you for answering so quickly but the leaves didn't turn yellow they just dried up.  The aphids aren't here yet and the drainage in the pot is great (maybe too great?).  I appreciate you telling me to plant in the ground, I was worried that the ground might still be too cold since we usually have to wait until Memorial Day to plant around here.  I'm leaning toward your "transplant shock" suggestion.  I have read that Wisteria doesn't like to be transplanted.  I'll watch and wait and hope for the best and I thank you again for sharing your knowledge with me.  Keep your fingers crossed!   Gail

Answer
Hi Gail -
Sorry I misunderstood about the leaves; I think it probably is transplant shock (or at least I hope so, since that's the "simplest" answer in how to approach the leaf-drop problem) - I am not familiar with northern Nevada conditions except to note that your nights can get really cold. One thing to remember is that root systems (as opposed to the portions of plants above ground) actually dry out (and even freeze) more quickly in a pot than they do in the ground.  I am definitely keeping my fingers crossed, Gail, good luck to you!