Q. I have a healthy sago that is outgrowing its space rapidly. When is the best time to relocate it? Is relocation successful usually? It is such a nice plant that I hate to risk endangering its life.
A. You would move it this fall, some time between the end of September and mid-October, or next spring. You should not have a problem relocating it. I would not put it any closer than five feet from anything you don't want it to touch or invade like a sidewalk or wall.
Hopefully you will put it on the north or east side of a building or in a spot with a little wind and sun protection and not use rock mulch around it. Pre-dig your hole for the plant. Make sure the hole and soil for replanting are prepared well with compost and a starter fertilizer high in phosphorus.
Remove the bottom tier of fronds from the trunk. I would leave only the fronds which are at about 45 degrees from horizontal and the inner fronds. Remove the older ones that are below this point. Bend the remaining fronds up around the central bud and wrap some twine around them to hold them together if they are pokey.
Take as much of the root system you can when you move it. Cut deeply with your shovel all the way around the plant about a foot to 18 inches from the trunk. Cut the roots in a complete circle all the way around the plant at least twice making sure all the roots are cut. Cut as many of the roots as deeply as you can.
On the third trip around the plant cut in the same spots but push down on your shovel handle and begin leveraging the palm upwards. Move to a new spot and repeat it until you have gone around the plant, leveraging and lifting, the third and fourth time with your shovel.
The plant should almost be free now or, if you are in luck, it can be lifted by the fronds. If not, then push the plant on its side and cut any remaining roots with your hand shears to free it. Tying the fronds up should make it easier to do all this and move it.
Move and orient it so it looks nice. Don't worry about orienting it the same compass direction as it was before. Backfill around the plant and run water in the hole at the same time you are backfilling to remove any air pockets.
Plant it the same depth as it was in its original hole, no higher or deeper. Put a small moat around the plant to contain water from the hose when hand watering. You can drip irrigate the plant but still hand water it for the next 2 to 3 weeks, filling the moat each time. Untie it and release the fronds.
In the spring, remove the bottom layer of fronds at the base of the crown just leaving juvenile fronds that are upright. You will see new growth from the center and it should regrow and fill the canopy in the first year.