|Are mums perennial in Colorado, the Denver area? Do they require special care in winter such as a spot near a tree to keep slightly warmer soil or a wind sheltered sunny spot?|
|Fall mums or hardy mums that you purchase in garden centers are hardy in your gardening zone (florist's mums are not so if you have a gift plant from a florist, expect to treat it as an annual).
Fall mums prefer to be planted in an area that receives full sun, but most cultivars can get by with a half day of direct sunshine. For ultimate growth, plant your new fall mums in fertile well drained soil. Poorly drained soil is the leading cause of winter mortality. Young plants, those in small containers, should be planted 18" to 24" apart. Mature plants can be planted at any desired spacing providing they are planted no closer than just touching its neighbor.
One of the most important tips in over wintering fall mums is to keep the soil moist as winter approaches. If you're the tidy type... after several hard frosts have blackened the plants, cut them back to near soil level. If not, just leave the plants until the next growing season and cut them back then.
Mulching your fall mums to a depth of 3" - 4" after the soil has frozen will help to ensure their return the following spring. The purpose of mulching your fall mums is to keep the soil frozen.
Once your fall mums start re-growing in the spring, remove the old stems if you haven't done so previously. This is the time to start feeding your fall mums with your favorite plant food every month until August.