Be selective when choosing a Christmas tree

When choosing a Christmas tree, select one with firm needles that don't drop off when the tree is raised up a few inches and dropped to the ground. A small number of needles dropping is normal.

The bottom of the stump should be moist with some sap present. Trees that were cut many weeks or even months ago will drop their needles shortly after being brought indoors. The trees that retain their needles the longest are the balsam and white firs; red, white and Scots pines; and Douglas fir. Once the tree is at home, cut another 2 inches or so off the stump and immediately place the tree into a stand with water.

Make sure the stand is full of water each day. A freshly cut tree can absorb as much as one gallon of water in a day and you may need to refill the basin more than once a day for first few days after installing the tree inside. If left in a stand without water, the tree will form a seal across the stump that prevents it from taking up any more water.

Dry trees can become serious fire hazards. Keep live Christmas trees away from heat sources such as fireplaces, radiators and furnace vents and check daily for water to maintain the tree in the best possible condition.

• Be selective if you are buying greens to decorate containers. I have found an occasional bundle of greens for sale that were “dry” and would not last long on display. These greens likely dried out because of the unusually warm weather we had in November. The live cut greens do not last nearly as long when the weather is warm.

I like to push the branches into the growing medium left in the containers so they are supported. Monitor the weather to install these greens before cold weather freezes the pots.

• Since November was so warm, you may need to mow your lawn one last time. I like to make the last cut of the season shorter (2 inches) to reduce the chance of snow mold developing over winter. Leaves are dropping later than normal, so you may have some clean up to do yet this fall.

I wait until spring to cut back most of my perennials and let some leaves stay in the beds as a natural mulch over winter. There has been a good amount of rain so most of your newly installed plants should not need to be watered. Check the root balls to see if they are moist if you are not sure. The window for installing bulbs is also later this year due to the warm weather.

• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.