Q. How do you start and grow rhubarb? &emdash; Gerald Wicoff, Danville, Ill.
A. Rhubarb can be planted in the spring as soon as the ground can be worked. Choose crowns of a known cultivar with at least two large buds. Valentine, Canada Red, McDonald and Ruby are recommended red cultivars. Victoria is a recommended green-stalked cultivar. Valentine tends to produce fewer unwanted seed stalks. Valentine and McDonald require less sugar in food preparation than many of the older cultivars.
Place the crowns 3 feet apart in rows that are 5 to 6 feet apart and plant them only 2 inches below the soil surface. Rhubarb thrives in a weed-free situation. Each spring, hoe the area carefully but thoroughly. Add a layer of mulch to control weeds and retain moisture. Fertilize after harvest with one-third pound of ammonium nitrate per 100 square feet of bed space. You’ll need to divide and reset the plants every eight to 10 years for rejuvenation. Old plants produce inferior, slender stems.
For more information, contact Purdue Agriculture’s Media Distribution Center toll free at 1-888-EXT-INFO and request publication HO-97 (Rhubarb). Indiana residents can obtain a copy by calling their local county Extension office.
Q. Someone wrote to your column about using tobacco for insecticide. I would like some information. Also, I need to know of something to spray or dust on tomatoes. Something ate the ripe ones fast. I use Sevin until picking time, but what can I put on through picking time? &emdash; S.L. Fulk, LaOtto, Ind.
A. Several readers asked about using nicotine as an insecticide to control Japanese beetles. Nicotine is a very toxic substance, and I would shy away from it. There are labeled products on the market. It’s far safer to use Malathion or Sevin to control Japanese beetles.
You need to identify the pest that’s gobbling up your tomatoes before you can choose something to spray on them. In my experience, tomato hornworms are the fastest consumers of tomatoes in the insect world. Since they’re as large as your finger (but light green), they are easy to hand pick during harvest time.
Q. I have noticed some green marks on the trunks of my pear, apple, plum, shade poplar and elm trees. Some of the trees look as if a wet paint brush was thrown against the trunk. Should I be concerned about this? The trees appear to be healthy. The pear and apple trees are producing quite a bit of fruit, soon to be harvested. The plum trees bloomed early and the frost stopped any fruit. &emdash; Ed Stegman, Crown Point, Ind.
A. There are a number of possibilities. Lichen can produce marks on trees but have no detrimental effect on them. In this case, you would take no action. However, herbicide drift also can scar trees. Have any herbicides been sprayed in the area, perhaps on the surrounding lawn or a nearby farm? Are the marks all on one side of the trees or are they uniformly scattered on the trunks? Arm yourself with some photos of the green marks and the answers to these questions, then talk to your county Extension educator. The fact that your trees appear to be healthy is a good sign. The trees may have experienced a tolerable level of damage, but you’ll want to avoid any future damage by identifying the source.