You will wake up to several days of frost by the end of the October. Protect tender garden plants and fruit from light freezes by covering them with blankets, sheets, plastic, or cardboard. Several commercial frost cloths are also available. You just need to keep the moisture off the leaves and the temperature just a couple of degrees warmer. Before a hard frost, when night temperatures will stay at freezing for several hours, harvest tender plants and fruits. Fried green tomatoes can be an especially nice late fall treat; pick, wash, slice, dip in whipped egg, dip in corn meal, and fry in your favorite oil for 1-2 minutes.
For more hardy plants like root crops, you can leave them in the ground until you are ready to use them. Root crops include carrots, turnips, potatoes, beets, winter radishes, and parsnips. If you remove the greenery and cover them with straw, mulch, or soil you can store them in the ground for another month. For more information on extended in ground storage see the Colorado Extension Service Factsheet.
Save yourself some spring clean up by removing dead plant debris from annual and vegetable beds after a hard freeze. In areas where tree and shrub roots won’t be damaged, recently frozen vegetation, leaves, and compost can be roto-tilled into the soil.
This is a great time to plant cool season annuals like pansies and primrose. Warm soils keep the roots growing and cool air keeps them blooming. Hand water in generous amounts after planting and during extended dry periods until established.
Sow seeds of self sowing annuals like poppies and cosmos.
Continue planting bulbs such as tulips, daffodils, crocus and others until the ground freezes, usually in November. A general rule of thumb is to plant the bulb two to three times as deep as the widest part of the bulb. If the tulip is 1.5 inches wide, then it should be planted 3 to 4.5 inches deep. Restrain from fertilizing except with bulb food as bulbs are very sensitive to salt damage. Bulb foods have a different chemistry and lower amounts of nutrition that are specifically formulated for bulbs.
A good design tip that also saves some digging is to plant bulbs in clusters or groups. Try placing 8-10 bulbs in a 1 foot wide hole about 1 inch apart from each other. This concentrates the blooms giving you a stronger display of color. Late blooming daffodils can be planted with early blooming varieties to extend the bloom time. This is done by planting 6-8 bulbs of the late variety as listed above, then placing the early variety of bulbs in between and finally back filling.
Wrap the trunks of newly planted and young trees to protect them from winter "sun scald" and from damage by mice, rabbits, and other animals. For larger pests, corrugated plastic drainpipe that has been split lengthwise down the side works well. For sun scald and smaller pests, white cloth about 4 inches wide wrapped around the first 1-2 feet of the trunk works well. Secure the wrapped ends with several lengths of tape. Sun scald happens commonly on thin barked trees like fruiting cherries and young maple trees.
Because plants are going dormant, this is a great time to transplant or move deciduous trees and shrubs. Dormancy is shown by the change in leaf color and dropping of leaves. Keeping the root ball intact as much as possible will aid the success of the move. To help with this, try not to have the soil extremely wet, but mildly damp. Handling the tree by the root ball and not the trunk will also help the keep the root ball together. After transplanting, apply water slowly to the root ball for the next several days to ensure the newly exposed roots can access water and keep the tree turgid.
Continue to add to your compost pile with garden waste; leaves, grass clippings, and other vegetative materials. Remember a happy compost pile has air and moisture, so stir it and water it. Try not to add weeds that have gone to seed, diseased clippings, or any kitchen waste containing meat products.
Deep-water evergreens to prepare them for winter.
Move tender perennials and other potted plants into protected or heated enclosures prior to a killing frost. This includes tender pond plants like locusts, papyrus, and some water lilies. Make sure to thoroughly spray down leaves to remove as many insects as possible. Trim off dead and older leaves that may become a source of disease.
Open sprinkler valves and drain water from sprinkler systems to prevent freezing. This is done by first turning off your main water source that supplies the sprinkler system. Then open each valve for several minutes to release any water or air pressure in the line. If your pipes are installed less than 12 inches deep in the ground without drain valves, it may be best to use an air compressor to blow remaining water out of the lines.
Dig the hole and prepare the site for the future planting of your live Christmas tree.