My iris developed seed pods. What should I do with them? My rhubarb also developed seeds earlier this spring and I'm wondering if I should have done something with the seed stalk.
Some iris, Siberian iris in particular, will produce seed pods that turn deep brown in the fall. These pods can make an attractive addition to dried flower arrangements, and they also add some winter interest if left in the garden.
The downside to letting iris -- or most any other flower -- develop seeds is that it might reduce the vegetative vigor of the plant. Here's why: It takes food energy for the plant to develop fruits and seeds after flowering. If the faded flower is removed instead of allowing a seed pod to develop, the energy that would have gone to seed production is redirected back towards growth of leaves, stems and roots.
Letting flowers go to seed doesn't necessarily have a big impact on the overall growth of the plant, but many gardeners deadhead old flowers for aesthetic reasons, as well.
The same principle applies to your rhubarb. Though the tall stalks of delicate, creamy white flowers are rather pretty when they appear in spring, the flowering and subsequent seed production might reduce the rhubarb's vegetative growth. If you want to prevent your rhubarb from setting seeds, cut the flower stalks as soon as you notice them growing.
I have several large Regent serviceberries in my yard. I was going to harvest the fruit this year and make a pie, but robins ate them before they even ripened. Is there such a thing as a spray repellent for birds?
Robins, catbirds and cedar waxwings frequently eat fruit, including serviceberries (Amelanchier spp.), strawberries, blueberries and cherries. They do seem to have a talent for gobbling up the fruit just before you intended to go out and pick it.
While there is no effective spray repellent for birds, you can try scaring them away. Drape the tree with scare tape; this is thin, shiny metallic tape that shimmers as the wind hits it. Ideally, the motion and flashes of reflected light will startle the birds enough to make them fly off. There are also many objects -- balloons painted with what looks like a large, threatening eye, owl statues, inflatable snakes -- that are designed to scare birds. Unfortunately, these devices usually have limited effectiveness because birds often become accustomed to them and blithely ignore them while dining on your fruit.
The only sure way to keep the fruit to yourself is to physically keep the birds away from it. This will require covering your serviceberries with mesh netting before the fruit starts to color. The mesh squares must be small enough (about 1/2 inch ) to keep out the birds. Even with that size mesh, birds may peck at fruit that they can reach through the netting. The entire plant must be covered, and the edges of the netting tied or taped firmly around the trunk so that birds can't get up and under the netting.
Nancy Rose is a horticulturist, writer and photographer. To ask her a gardening question, call 612-673-9073 and leave a message. She will answer questions in this column only.