A Greener View by Jeff Rugg

Q: Something is eating the waterlily leaves in my pond. Someone at a store told me that frogs would eat them. Someone else told me it was the goldfish. Then another opinion blamed the snails. My once-blooming waterlilies are now chewed up. I appreciate your opinion and what I can do.

A: Let's take them one at a time. Frogs only eat algae and other plant material when they are tadpoles. Even then, they rarely do much damage to waterlily leaves. Goldfish also rarely do much damage to large plant leaves. They do eat some algae, and they might injure some smaller underwater plants or the roots of floating plants. Large cousins of goldfish, koi can damage and eat waterlily leaves. They usually tend to suck up the gravel and mud around the base of the plant — uprooting it so it floats around. Some people put algae-eating fish like plecostomus in their ponds; they will eat all the vegetable matter they can find after getting algae. Snails are also after the algae and rarely damage waterlily leaves.

Most likely, your plants are having problems with China Mark Moth caterpillars. Making little sleeping bags out of the pieces of leaves, the caterpillar eats the rest of the leaf from the protection of the covering. These tiny (a couple would fit on a penny) leaf bags can be easily seen on the tops and bottoms of the leaf. Just pick them off and squish them or throw them away.

The insecticidal bacteria, Bacillus thuringiensis, can be used on the larval stage of moths.

It must contact the larvae, which in this case may not be easy because the caterpillar will stay on the leaf wrapped in its protective shelter. The eggs are laid under the leaf, so wipe the leaf off with vegetable oil or rubbing alcohol on a cotton ball.

Q: My Yukon Gold potato has developed fruit. They are green, golf-ball sized, and they look like tomatoes. I have grown potatoes for years, but I have never seen anything like this. What is going on?

A: You may have missed it before, but your potatoes are producing fruit. Potatoes are in the same plant family as the tomato, so the fruit look similar.

Most people grow new potatoes by using pieces of the tuber, which is part of the root system. These pieces are often called seed potatoes, but they are not related to the seeds at all.

If you wanted to grow a new hybrid potato, you would have to cross the pollen from one kind to the potato flower of another kind. Then you would need to grow new plants from the real seeds produced in those fruits. If you are not trying to create hybrids, it is not worth the bother to grow potatoes from seeds.

Just cut off any new fruits and toss them in the compost pile. Yukon Gold is one of the newer yellow-tinted potato varieties that have a moister flesh compared to the older white varieties. Since it is new, you may not have grown it before. And the old varieties you did produce may not have been prolific fruit producers.

E-mail questions to Jeff Rugg, University of Illinois Extension at jrugg@illinois.edu. To find out more about Jeff Rugg and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

COPYRIGHT 2010 CREATORS.COM