Our fall-shipped plants may still be growing, or may not have had enough exposure to cold temperatures, to have started hardening off for winter when we ship them. If you are in a USDA Zone 6 (average minimum winter temperature 0 to -10° F) or colder location your new plants will need some extra care to establish and survive their first winter. In warmer (USDA 7 or warmer) locations fall is an ideal time to plant, roots have the entire winter to establish in the ground, and fall is generally long enough to allow the plants enough time to harden off properly before winter.

            In all zones follow the regular planting instructions in the Owners Manual and be sure to mulch well afterward. Mulch helps protect the roots from winter freeze damage. Keep the mulch at least 2” away from the trunk of your plant to prevent rodent damage. Water in well at planting, and then as needed to keep the soil evenly moist. Do not fertilize, except for some bonemeal or other slow release source of phosphorous.

            When severe weather threatens, such as a sudden major decrease in temperature, overnight temperature predicted to be more than 10° F lower than temperatures that have been experienced so far, or day time temperatures will stay below freezing, new plants that are not sufficiently hardened off could be damaged. If there is no snow cover to protect your new plants from drying freezing winds or persistent below freezing temperatures, pile lose straw or other insulating material around the plant, and then cover with plastic to keep dry. Provide support if there could be snow that would crush your plant under the plastic. Remove the cover when the threat of severe weather has passed, but keep handy in case there is another weather event.

Zone 6 and colder locations. In areas where winter temperatures will be experienced within 4-6 weeks of planting (before roots have had time to establish), or where severe temperatures are typical by mid-November, and/or the ground tends to freeze more than 1” deep, it might be better to hold the plants in their containers in a protected location until time to plant in spring. While the plants are dormant and have no foliage light is not required, temperatures between 30° and 40° F are ideal. Keep the soil evenly moist but not soggy. If you have to hold the plants long enough that they start to grow, but can’t plant yet, provide light and keep them at the same cool temperatures. Follow standard hardening-off procedures when you plant out in the spring.

Most of the potted plants have been growing in the pots for awhile and should be removed from the pot. Gently, with one hand cradling the soil and the crown of the plant, tip the plant out of the pot and inspect the roots. If you are careful the soil will stay intact around the roots. You don’t need to wait for the plants to lose their leaves to plant them in the ground. However, it’s best to plant when you are expecting overcast or rainy days to follow. In the Pacific Northwest we generally have a dry summer and fall. Unless you receive fall rains that saturate the ground you will need to keep an eye on your new plantings, water enough to keep the soil moist but not completely saturated to encourage strong root growth.  

            What if the roots fill the pot or are winding around?  Either replant to a larger pot or plant into the ground. In either case, use your fingers to gently pull the roots apart a bit, or if there are a lot of winding roots they need to be cut off. Use a sharp knife, or serrated knife, to slice off the matted roots around the sides of the root ball, then slice off the bottom of the root ball. Poke into the rootball with a pointed instrument and wiggle about a bit to loosen compacted soil.  Loose roots should be trimmed off. The very top of the root ball (crown of the plant) should be at or just below the soil surface when you are done planting. Be sure to read the enclosed Owners Manual for specific planting instructions for individual plants.