1. Prepare the planting hole - make it twice the size of the potted plant. Now is the time to improve soil conditions around the plant by adding sand to improve drainage of heavy soils and peat moss or compost to improve water retention of all soils. Then fill the planting hole with water to give a thoroughly moist planting area. Let this water drain away before placing the new plant in this hole
2. Potted plants which are on the dry side should be thoroughly moistened before planting. You can place overly dry plants in a bucket of water for about 5 minutes to get the soil mixture well wetted.
3. Loosen the root mass of pot-bound plants. This can be done after removing the plant from its pot (remember, don’t pull the plant out of the pot by pulling on the stem – invert the pot and tap the plant out of its pot). If the root mass is loose enough, simply use your fingers to pry open the root mass in about 4 places. It the roots are tightly bound, use a sharp knife to make a 1/4" deep length-wise cut down the length of each side of the root mass. This will encourage new roots to grow out into the soil rather than be confined to the pot-shaped root ball.
4. Set the plant in the planting hole and fill in the hole with soil and add water (remember - no fertilizer) to the planting hole area to settle in the plant. In newly prepared beds, set the plant so that it is 1 or 2 inches above the surrounding soil level. In all cases, make sure soil or mulch covers the potting medium. Leaving the potting medium exposed to wind and sun actually wicks away water from the root system and causes unwanted water-loss stress.
There are many perennials that can be divided and planted successfully in the late summer and early fall. The plants in the following list are ones that we routinely dig, divide and place in pots for sale the following spring. Home gardeners can successfully do the same. When replanting your divisions, make sure that you cut back the vegetative top growth (stems & leaves) by 1/2 to reduce water-loss stress.
