I had Homestead Gardens plant a redbud in my yard. It died in within the year without blooming or leafing They replaced it with another tree, a Forest Pansy in another part of the yard. It too died. I don't want to try again and they will not do it without charge. They suggested I contact you about it. Perhaps to test the soil. The first tree was planted about 5ft. from a black walnut tree which is why I had them plant it far from the other . Do you have any suggestions for me?
You can have the soil tested in the area but it will not tell you why the tree died. Soil test results give pH, liming, and nutrient deficiencies. http://extension.umd.edu/hgic/soils/soil-testing
Redbuds tolerate a pH range of 6-8. It does well in most soil types and prefers a moist well drained soil. It does not like permanently wet soils. The tree grows well in full sun but prefers some afternoon shade as it is considered an understory tree. http://www.clemson.edu/extension/hgic/plants/landscape/trees/hgic1021.html
Here is a publication on Black Walnut from Va Tech. Redbud is tolerant to juglone. However, it is a good idea to plant as far as possible from the root system so there is not a lot of root competition for moisture and nutrients.
We do not know how the tree was planted or the site conditions. Usually when plants decline within the first year or two of planting it is due to poor soil conditions, poor drainage, poor planting techniques, too much or not enough water, planting too deeply, too much mulch, girdling roots, etc. Look at our publication on these types of problems http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG86%20Common%20Abio...
Make sure the tree was not planted too deeply. You should see the flare at the base of the trunk where it joins the root system. Make sure mulch is no thicker than several inches and keep away from the base of the trunk.
You did not mention if the tree was balled and burlapped or in a container. If balled and burlapped was twine and synthetic burlap removed? Look at the planting process for container trees below.
Check the soil drainage in the area. Does it drain well? What were your watering techniques? You will have to water deeply enough to penetrate the root ball. You may have to probe with a screwdriver and check for this. Look at our website for the planting process and post planting care