Q. I have one ‘domestic’ walnut tree. Every year, just before I think they are ready to be harvested, I come to the tree to find it has been stripped bare. I assume the culprits are squirrels. How can I tell when they are ready so I can get to them first next year?
– Irvin Goldstein
A. Collecting the nuts before they are truly ripe would lower the quality of the crop. You’re better off trying to exclude the squirrels if you can. If the tree stands alone and the squirrels can’t get to it via nearby trees, you can attach a collar around the trunk to keep them from climbing it. If they have easy access to the tree canopy, it will be almost impossible to hoard your harvest. Jerry Lehman, a local nut expert, says, “Unless one has a very large acreage of nuts–more than the squirrels can carry away–one can have squirrels or nuts, but not both!”
Q. Our tomato plants got yellow leaves on the bottom and died in early August the last two years in a row. We tried a different part of the garden this year but with the same results as last year. Is there something we can treat the soil with or the plants when we plant them?
– Harv and Linda
A. Tomatoes have so many qualities, including an abundance of choices in size, shape, flavor, growth type, color and, unfortunately, problems. Your tomatoes may have fusarium wilt but could, instead, have verticillium wilt, black walnut toxicity, nematodes or a number of other maladies.
Fusarium wilt causes the lower leaves to turn yellow, wilt and die. Then the upper shoots wilt, finally killing the entire plant. To decide if this is affecting your plant, cut open the stem lengthwise near the soil line. The tissue inside will be dark brown. Those are the water-carrying vessels, and they have been plugged up by the fungus, blocking water and nutrient uptake.
Fusarium fungus is spread by infected soil, tools, plants and seeds. There is no chemical control. Remove and destroy infected plants immediately. In the future, look for plants that are resistant to fusarium wilt as designated by the letter “F” after the variety name.
For more information on the other possibilities, contact your county Extension office or get online for publications. You need “Five Steps to Healthy Garden Tomatoes,” which describes the common tomato diseases (http://www.agcom.purdue.edu/AgCom/Pubs/BP/BP-3.html) and “Black Walnut Toxicity” (http://www.agcom.purdue.edu/AgCom/Pubs/HO/HO-193.pdf).
Q. I have a one-year-old gardenia plant. I keep it indoors in a north window. Recently, the leaves and buds have been turning black and falling off before any blooms occur. The new leaves and buds look healthy to begin with and then turn black from the tips and eventually fall off. I thought I was overwatering, but keeping the soil drier doesn’t make any difference. Help!
– Roz Moore, Lafayette, Ind.
A. Gardenias are finicky. In order to hang onto their buds and leaves, they require high humidity and warm temperatures. Any change in their daily life can cause the leaves and buds to yellow and drop. Since you described the buds as black instead of yellow, I suspect salt damage caused by a lack of drainage and a build-up of fertilizer. Does the pot have drainage holes?
Always water thoroughly, until the water drains through the holes in the pot. This washes out accumulated fertilizer salts. If you see a white ring or crust near the soil level, you need to leach the soil. Place the pot in the bathtub or sink and flush the soil with water several times.
Persimmon Propagation
In an earlier column, a reader wrote about difficulty transplanting persimmons. Persimmons may be most successfully transplanted in late fall, not spring. Dig up as many roots as possible, plant in the new location and mulch heavily.