Pests and diseases 69
ones I have in my own gardens were either given to me by my grandmother or by
a friend, or are reblooming forms I wanted to test. I enjoy them enough when
they are flowering, but I don’t find Iris ×germanica to be worth the trouble of the
horrid leaves that follow. Of the reblooming forms, I have been happiest with one
called ‘Perfume Counter’, a purple-flowered cultivar whose foliage holds up
much longer than that of other forms.
I feel the best alternative to bearded irises are Siberian irises (Iris sibirica).
They add such great vertical form to the garden, and the flowers are gorgeous.
The seedpods can be even more interesting than the flowers, contributing to the
garden for the entire summer and winter. (Cut them in the spring for use in dried
arrangements.) The foliage turns yellow in the autumn, providing ornamental
benefits in that season. And best of all—no pests!
Many people simply must have bearded iris, however, in which case a few
tactics can be employed to fight the borer. If you can see it, crush the borer in the
iris leaves. When the leaves are badly affected I cut them down to a few inches
above the rhizome—it looks tacky, but better than the previous brown-spotted
option. Cutting at an angle reduces the “crew cut” look. I also just pull out the
brown, curled-up leaves at the base of the plants. In the autumn, it is important
to cut down the leaves again, and remove any brown leaves at the base of the
plant, because the borer eggs overwinter on them. Do not compost infected iris
leaves. Planting the rhizome high so that it is exposed to the sun helps reduce
bacterial soft rot (Pectobacterium carotovorum), which often sets in after the
borers and in fact causes most of the trouble.Leafminer
Leafminer can be handled simply by pruning off infested leaves or by cutting the
entire plant to the ground when symptoms get severe. Do not compost leaves
and be certain to clean up debris in the autumn. Trying to prevent leafminers is a
waste of effort because they don’t cause long-term harm to the plants.Japanese beetle
The main pests I have to contend with in my gardens are Japanese beetles,
fourlined plant bugs, and grasshoppers. If you have small numbers of Japanese
beetles, you can pick them off and put them in soapy water. But is it possible to
have small numbers of Japanese beetles? I never have. I get masses of them in
disgusting numbers. They are so taken by my rugosa roses (Rosa rugosa), which
they practically destroy each year, that they usually leave my perennials alone,
except for Kirengeshoma palmata and Alcea rosea. When my son was young, he
would start watching for the beetles in early June, and we both derived great
pleasure from catching them, smashing them, or even more rewarding, putting
them in one of his bug boxes, with plain water, and using them for fish bait in our
pond. Bluegills and bass love them. Even the catfish go for them if they are
hungry enough. We would throw clumps of Japanese beetles into the water like
chum to attract the fish. It’s a bit scary how gratifying this bit of gardener’s
revenge can be, particularly baiting the hook! The only problem is keeping up
with the quantity that eventually descends on the gardens. I have tried using
traps placed about a hundred yards away from the gardens, and this has some-
times helped in reducing the numbers, but there is always some fish bait
available even in September. If you live in a residential area, you probably will
only attract more beetles to your garden with traps. If you do try them, the traps
should be placed as far away from your beds as possible.