With the highest average elevation of the 50 states, vegetable gardening in Colorado can definitely be challenging. Experienced Colorado gardeners have learned to expect the unexpected when it comes to the weather. On the bright side, Colorado averages 300 days of sunshine a year, which is perfect for sun-loving vegetables. Plant hardiness zones in Colorado range from 2b to 7a, reflecting the wide variation in altitude and climate.
Choose a well-exposed location that gets plenty of sunshine. Vegetables grow best with at least six hours of sunlight a day. If your land slopes, try to select a southern exposure for increased light and warmth. Terracing may be required on very steep land to prevent water runoff. Place the stakes in the corners of the plot as markers.
Remove grass, plants and other debris from the plot with the spade. Dig down far enough to remove as much of the roots as possible. Loosen the top 4 to 6 inches of the bare soil with the spade or hoe. The soil in Colorado is typically very high in clay. You will need to amend it by adding sand and organic material, such as aged compost or manure. Spread 2 inches of sand and 6 inches of organics over the entire plot. Turn the soil to blend in the new material and leave the plot to rest for about a week before planting. This gives the organics time to start breaking down into the soil.
Draw a sketch of the plot and plan your garden. Small vegetables such as onion, beets and carrots can be planted in rows 18 to 24 inches apart. Helpful advice on what to plant and when is available from your local Colorado State University Extension office. Draw the rows on your diagram and label where each variety will be planted. Always orient the rows north-south to maximize the exposure to light.
Rake the plot level and mark out the rows with stakes and string according to your drawing. Pull the soil into a 6-inch high mound along the length of each row. Follow the package directions and plant your seeds at the recommended spacing and depth. Keep the seeds and soil moist after planting by spraying the garden with a fine mist of water.
Water your garden early in the day when it is cool. Be careful to direct the water to soil to avoid washing away seeds or getting plant foliage wet. Wet leaves attract both bugs and disease. Your vegetables will need at least 1 inch of water each week. Remove any weeds as soon as they appear. As the vegetables grow, keep an eye out for signs of damage from insects or disease. Contact your local county extension office for advice if problems arise.