|I have a Bowles Mauve wallflower planted Spring 2007. It bloomed all year except for mid to late January and then was absolutely glorious this Spring (2008). Now it seems to be dying. At least it has underneath limbs that are bone colored and very dry and in many of those that are not entirely bone colored and still have leaves, the leaves are turning bone colored and falling off. There are still blooms at the tips of the stalks although not as plentiful and the stalks are mostly bone colored. I have watered as usual and see no signs of insects. We are in drought, although not as badly as last year. Any ideas about what is happening and what I might do to save it? I also have a 2 yr. old Zebra Mallow that is quite tall and has already got little seed pods on most of the limbs and much fewer leaves. There are still flowers at the tops. It is almost like it is setting seed very early.
|'Bowles' Mauve' is a hybrid evergreen perennial form of Erysimum and does not reseed like the more common biennial wallflowers. It does root quite easily from cuttings though, which is a good thing as the plant is not very longlived. It quite literally blooms itself to death after a couple of seasons - 2-3 years is about as long as you can expect for good performance before it starts to decline. I'd take tip cuttings or replace the plant with a new one.
The story is the same for your zebra mallow. An old Cottage-garden favorite, this cousin to the Hollyhock has similar satiny flowers in a soft lavender-purple shade, exotically striped with deep maroon veins. It forms an upright, bushy mound that may need to be staked if grown in rich soil. This is a short-lived perennial or biennial, often flowering itself to death in the first year, but coming back the next year from self-sown seedlings. I'd allow the seeds to develop and spill into the garden bed. Next spring you'll have lots of new plants.