Most varieties of poppy plants don't respond well to transplanting. In fact, you should avoid transplanting poppy whenever possible. If you must transplant, follow these steps to give your poppies the highest possible chance of survival.
Step 1 - Prepare to Transplant Your Poppy Plants
Before you get started, make sure that you have chosen a suitable new location for your poppy plants. It should have the same amount of sunlight that the plants are used to receiving. Dig large holes that will be ready to immediately accept each transfer. Prepare the soil in your new location before digging out the poppy plants.
Step 2 - Prepare the New Location
Prepare the soil in the new location by thoroughly turning and cultivating it. Mix in some high-quality all-purpose fertilizer. Test the pH level of the soil both in the old location and the new location and try to match them as closely as you can. If you need to, you can add some lime to sweeten the soil and lower the pH level. Add some super phosphate or animal manure to provide additional nutrients as well.
Step 3 - Dig Up the Poppy Plants
Dig up the entire root system of the poppy plant. The roots can spread fairly wide, so begin digging far enough away that you can get the whole root system. Once you remove the plant, do not attempt to divide it or shake off any loose dirt or debris. Simply take it to the new hole and insert it.
Step 4 - Replant the Poppy Plant
Once you have the plant in the hole, pack plenty of dirt and soil around it as quickly as possible. Add another application of all-purpose fertilizer and 2 or 3 inches of organic mulch to help protect the root system.
Step 5 - Continue Care for the Plant
Your transplanted poppy plant will need continuous care in order to survive. Add all-purpose fertilizer to the plant every 7 to 10 days until the plant displays signs of new growth. Also, while the root system attempts to reestablish itself, root rot will be a constant concern. To prevent this diseases, water your poppy plants often, but take care not to soak them.