When planning your vegetable garden each year, it is a good idea to avoid planting crops from the same family in the same location in consecutive years. The idea behind crop rotation is to grow different groups of vegetables on different beds each year and move them around in sequence such that they aren't growing on the same plot for two to three years. The benefits of crop rotation include:

Reduction of soil-borne diseases and pests that overwinter in the soil
Many insects and disease organisms attack plants in the same family, while not infecting unrelated plants. Growing the same crop, or different crops from the same family, in the same location for several years may lead to a build-up in insect populations or a severe disease outbreak. Rotating vegetable crops will disrupt the life-cycles of the insect pests and disease organisms, reducing their chances of building up large populations or infestations in the garden.

Weed control
Some crops (squashes, pumpkins, cucumbers, potatoes) shade the soil around them and are quite effective at suppressing weeds, reducing the number of weeds that come up in that location the following year.

Improved soil conditions
Different crops have different nutritional requirements. Rotating crops over several years slows the depletion of various nutrients from the soil. Some crops (beans, peas, and other legumes) add nitrogen to the soil, reducing the amount of fertilizer necessary for crops grown in the same location the subsequent year. In addition, alternating between crops with tap roots, such as carrots, and those with fibrous roots, such as corn, allows for long-term improvement in soil structure.

The following list of crop families should be helpful to you in selecting plants for your rotation schedule. Remember, plants in the same family should not be planted in the same spot in the garden for at least two to three years, if possible.

Mustard Family: broccoli, cauliflower, cabbage, Brussels sprouts, kohlrabi, turnip, rutabaga, radish, Chinese cabbage, kale, collards

Nightshade Family: tomato, pepper, eggplant, potato

Legumes (Pea Family): beans, peas, soybeans

Cucurbits (Gourd Family): cucumber, squash, cantaloupe, watermelon, pumpkin, gourd

Chenopodium Family: beet, Swiss chard, spinach

Carrot Family: carrot, parsnip, parsley, celery, fennel, dill

Sunflower Family: lettuce, endive, Jerusalem artichoke, sunflower, salsify

Onion Family: onion, garlic, leek, shallot, scallion, chives

Q: Is it too late to plant my spring-flowering bulbs?

A: Spring-flowering bulbs can be planted during October, but the longer you delay, the more you risk a lack of root development and failure to bloom in the spring. Site preparation is the key to success, particularly if you have our typical clayey soil. Choose a sunny location that will drain well. Amend the soil with organic material such as compost, peat moss, etc. Be sure to plant at the depth and spacing for each type of bulb. Don't be afraid to "layer" different bulbs to create a natural bouquet of varying colors and textures in the spring. After backfilling the hole with amended soil, cover with a 3-inch layer of mulch to protect against freeze-thaw cycles that can damage the bulbs. Anticipate and enjoy the burst of color as these hardy flowers emerge in early spring.

Q: I'm planning some changes to my garden for next spring. How can I determine whether a certain plant I'm interested in is suited to our growing conditions?

A: Colorado State University Cooperative Extension provides a wide range of reference materials to help make wise plant selections, whether you are a newcomer to the high plains or an experienced gardener. Each year, the Cooperative Extension and the Denver Botanic Gardens collaborate with landscape and nursery professionals throughout the Rocky Mountain region to produce the Plant Select® list, containing recommendations for some great garden plants from the high plains to the intermountain region.

Q: Is it okay to plant or transplant trees this time of year?

A: Late fall tree planting can be risky in our area, especially for evergreens. If you are going to plant, do it now, and be sure to cover the planting site with three to four inches of organic mulch to help conserve soil warmth and moisture. If the fall and winter months are dry, be sure and water mature and newly planted trees and shrubs to prevent root damage. For more information on fall and winter watering, visit the Save Our Shade web site at watersaver.org

Many houseplant insect problems, especially infestations of mealybugs and whiteflies, are introduced when infested plants are purchased from a nursery or are received as gifts. Check plants carefully before purchasing and "quarantine" newly purchased plants and gift plants in a separate area for a few weeks to avoid introducing new pest problems into your existing houseplant collection.

To prepare strawberry plants for the winter, slowly reduce watering following the first frost to help harden off the plants for winter. Protect plants over the winter by covering them with a 1-2 inch layer of straw, applied around the first week of December. The straw will reduce moisture loss during the dry winter months and help protect against root damage caused by alternate freezing and thawing of the soil.

To keep plants healthy during fall and winter, water trees, shrubs and lawns during prolonged dry periods. Water only when air and soil temperatures are above freezing.

The authors have received training through Colorado State University Cooperative Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.

Gardening and Insect Fact Sheets are available on-line by clicking HERE.

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This page updated:  Octobe 11, 2004