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What is the latest news on using bone meal in the garden? I have heard conflicting views – some people swear by it, others say it’s worthless since most of the nutrient value is eliminated during the steaming process it undergoes, and then others are concerned about possibly introducing disease into the garden since this product is derived from animal bones. Please help clear up the confusion.

Bone meal is a source of slow-release phosphorus. Most retail bone meal products are coupled with slow-release nitrogen. Both of these elements are significant to good plant health and growth. They affect the plant’s vigor, its photosynthesis process, and its root growth. Many people add bone meal to their soil as a safety net. Perhaps it’s a little like taking a daily vitamin. They feel its nutrient value offsets any problems inherent in poor or unamended soil conditions. Most homeowners want quick results with minimum preparation. The plants respond accordingly to this organic fertilizer.

The commercial bone meal products available in the U.S. must meet stringent USDA regulations. The USDA has not allowed British beef or cattle-generated products to be imported. According to the USDA, during the late 1970’s England started using a heat-only method of treating animal carcasses that were to be used for protein-based meal and bone meal. Prior to that time, they used a combination of heat and solvent extraction. The USDA knows that heat plus solvent extraction kills the BSE causal organism (or mad cow disease), but heat without solvent extraction does not. The U.S. has never abandoned the heat plus solvent extraction method. It seems very unlikely that we need to be concerned about using bone meal in our gardens for fear of contracting BSE. The U.S. has never had a confirmed case even though the USDA has been actively looking for cases since 1989. Our method of preparing bone meal kills the BSE organism but does not dissipate the nutrient value.

Last year I had a large tree removed (36-inch diameter). I want to plant in the currently empty area, but between the stump and large roots near the trunk, it is virtually impossible. I had the stump ground down to grade level, but the machine could not remove the stump below grade. I piled on leaves and compost last year to help accelerate the decomposition process, but I am guessing it will be at least several years before the stump and roots are well-rotted enough to be planted amongst. I heard that there are products to help speed up stump decomposing. Is this true, and if so, are they organic? I do not want to apply anything that would be harmful to the soil.

The use of purchased products to speed up stump decomposition is not much faster than what you have already started. You can speed up the process by drilling some holes in the trunk which will allow air and water down into the trunk. You could even take this one step further by putting fertilizer in the holes. Then cover with leaves and compost and wait. In the meantime, look for some clever ideas to hide and disguise the area until it is ready for use as you originally intended.

Does putting marigolds and nasturtiums in or near a vegetable garden deter pests from entering the garden area? Or is this an old wives’ tale; can it actually be harmful because those plants attract insects that will feed on the vegetables?

Native to Mexico, the sun-loving nasturtium (Tropaeolum) and French marigold (Tagetes patula) both attract and repel garden pests. While slugs devour both types of plants, especially immature French marigold plantings, many gardeners nonetheless use these species as companion plants to protect some of their vegetables. Not all marigold species, though, do the job. Only mature French marigold plants, likely grown in Mexican gardens long before Cortez arrived, emit insecticidal compounds that help control many garden pests. French marigolds are reputed to chase away white flies as well as keep tomato plants free from root nematodes and bean plants free from Mexican bean beetles. French marigolds are also unpalatable to meadow nematodes (eelworms).

Nasturtiums, once grown for the edible seeds that replaced capers when pickled, are considered by many gardeners, but not all, to be good companion plants to tomatoes, radishes, cabbage, and cucumbers. However, some gardeners think nasturtiums attract whiteflies, aphids, and viruses and should not be grown near plants that appeal to these pests. Other gardeners plant nasturtiums to attract these very pests so they will ignore nearby garden plants. Still other gardeners contend that the high sulfur content in nasturtium leaves repels pests such as aphids, squash bugs, striped pumpkin beetles, and woolly aphids.

The vibrant reds, oranges, and yellows of French marigolds and nasturtiums are a colorful addition to any garden. Moreover, both plants flourish in poor soil and full sun. However, while nasturtiums thrive on neglect, French marigolds need frequent deadheading for continuous bloom. Nasturtiums offer an added bonus: both their flowers and peppery-tasting leaves are edible.

I have a wisteria vine that is healthy, and over 20 feet tall. This plant is three years old and has never bloomed. What can I do to get it to bloom?

Congratulations! You are well on your way to a blooming wisteria. A little basic biology may help you understand why it has not yet bloomed and what you can watch for to insure it does bloom. Wisteria seems to be a vine that thinks it is a tree; they can be so heavy that they need heavy duty support. That being said, your 3-year-old is just a baby and is not ready to bloom and set fruit (what plants do when they mature). The wisteria is a member of the pea family and the blooms are the precursor to pods (fruit). Be patient and do not start fertilizing; being members of the pea family, they are nitrogen fixers and form nitrogen-containing nodules on their roots. Overfertilization can stimulate foliar growth, but will not encourage blooming. Feeding it once a year with super phosphate to encourage root growth is about all it needs.

What is the cause for maple tree leaf veins to be much darker than the leaf itself?

What you are describing is symptomatic of leaf chlorosis. Chlorosis is the general yellowing of a leaf that can be brought on by a variety of factors. Disease, insects, cold weather, pollutants, a high level of minerals, or nutrient deficiencies can cause it. Your best course of action is to conduct a soil test. Call your county MSU extension office and they will help you obtain a kit complete with easy instructions. The results will help confirm or rule out problems in the soil. The test will also check the pH level in your soil. The correct pH level enables your plants to take up needed minerals and nutrients that are available in the soil. Read your test results carefully and if you need any clarification of the information, the extension office will again be glad to assist you.

Do cosmos reseed themselves? Do I take off the spent blooms or leave them to dry and fall off?

Most cosmos reseed themselves but not always reliably or true to the variety. The common cosmos in Michigan is an annual, so the best way to have nice plants that are the color and height you want is to sow new seeds each spring when the ground has warmed to 70 to 80 degrees. Or you can purchase plants from local garden centers. Plant them in full sun in the back of the garden where a fence or other plants can hold them up. They tend to flop in wind or heavy rain, and it is difficult to stake them because of their thin stems. In her book Annuals for Michigan, Nancy Szerlag suggests placing twigs around the young plants for support that will be covered when the plant is older. The plants germinate easily in the garden with only 1/8 inch of soil covering them. They are very drought tolerant and don’t need much, if any, fertilizer for the whole growing season.

To keep the plants blooming throughout the summer it is best to remove spent blooms. It also makes the plant look neater. If they get too tall and blooms are weak you can trim them back to half their height. They will grow back bushier to bloom again later in the summer. You can selectively cut them back, so there are still some blooming while the others grow back. If you want to encourage reseeding (and that means anywhere in the garden with help from the wind and critters), leave the seed heads on in the fall. The finches and other small birds love the seeds, and what they don’t eat may reseed.