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.

How do you go about looking for a good landscape company? We are planning on having some bushes planted next spring and need some landscape advice.

There are basic rules to keep in mind. Define exactly what you want the contractor to do and where. Make a list to organize your ideas and even a thumbnail sketch. Ask yourself how involved you will be with the installation and maintenance. Do you want to observe from the sidelines, or get in there and dig? Will you handle the annual maintenance of your new landscaping, or pay for that service? A single contractor who offers both installation and maintenance has greater continuity with your property than two separate companies. Know your budget and prioritize the areas you want planted. You may decide to do your plantings in phases. Once you determine these conditions, make a list of contractors that fit them. Two excellent sources are the Michigan Green Industry Association and the Michigan Nursery and Landscape Association. These professional trade organizations will have lists of companies who fit your criteria. Also ask friends and neighbors whose yards you admire how they accomplished it. You can learn a lot about the working relationship between contractor and homeowner that way. Then start calling. Be patient as most good contractors are very busy. Get at least three bids or plans, and get them in writing, with details about timetables, unforeseen changes, site repair from heavy equipment, etc. Ask them for references of completed projects and follow up on them. The more informed you are as a homeowner about the work you want done, the happier you will be with the end result.