Enclose the soil ball around the roots in a plastic bag and tie securely around the stem. This avoids having the roots dry out and having the soil sift onto the top portions of the plant during transit and destroying or obscuring symptoms on the stems or leaves. Wrap the entire specimen in another plastic bag. When entire plants cannot be sent or when only parts of plants are diseased as with leaf spots, stem cankers, or swellings, send several affected parts. Cut stem and branch specimens with a short piece of live healthy tissue attached to the diseased portion.
Place specimens in a plastic bag.
Fresh leaf samples keep very well in closed plastic bags. Do not add water or wet paper towels unless the sample is very dried out. Keep refrigerated until sample can be sent. Dutch elm disease or Verticillium wilt. If you suspect either of these diseases, select branches having wilted, yellow, or dying leaves.