Growing Grapes in Colorado Gardens: A Comprehensive Guide

Growing grapes in Colorado can be a rewarding experience, whether you’re aiming for fresh table grapes, juice, or even homemade wine. This guide will walk you through the essential steps for successful grape cultivation, from choosing the right cultivars to planting, trellising, pruning, and general care.

Types and Cultivars

Types of Grapes:

  • Table Grapes: Ideal for fresh eating, with popular seedless varieties like Himrod, Interlaken, Canadice, St. Theresa, and Reliance.
  • Juice and Jelly Grapes: Popular cultivars include Concord, Valiant, Niagara, and St. Croix.
  • Wine Grapes
  • Raisin Grapes

Cultivars:

  • American Cultivars (Vitis labrusca): Known for their strong “foxy” (musty) flavor and aroma, these are used for juice, fresh eating, and some wines.
  • European Cultivars (Vitis vinifera): With tight clusters and thin skins, these grapes are used for wines and require more heat units for maturity, making them less suitable for Colorado.
  • French-American Hybrids: Popular for wine, with characteristics that vary depending on parentage.

Planting Grapes

Grapes need full sun and protection from wind. Space plants 6 to 8 feet apart, in rows 6 to 10 feet apart, depending on your trellising system. Strong trellising systems are necessary to support the heavy vines and fruit. Use treated posts and 12-gauge or heavier wire.

Trellising and Pruning

Grapes fruit on one-year-old wood, making pruning a balance between fruit production and renewing wood. Proper pruning is essential for high yields and large clusters of grapes. Unpruned or under-pruned grapes will produce many small clusters of tiny grapes, while over-pruning reduces yield.

Single Curtain System:

  1. Pruning at Planting: Cut back to two to three buds to encourage the growth of a strong primary trunk.
    • Image provided by CSU extension
  2. Second Spring Pruning: Select one cane to become the trunk and remove others, leaving one or two renewal spurs.
    • Image provided by CSU extension
  3. Third Spring Pruning: Select two one-year-old canes to become fruiting canes and cordon arms along the trellis. Prune two other canes back to two buds each to serve as renewal spurs.
    • Image provided by CSU extension
  4. Fourth Spring and Beyond: Continue selecting new fruiting canes and renewal spurs each spring, maintaining the balance between fruit production and new wood growth.
    • Image provided by CSU extension

General Care of Grapes

  • Mulching: Use a four-foot-wide weed-free bark/wood chip mulch strip under the trellis to help retain moisture and reduce weed competition.
  • Watering: Avoid over-watering, as it can lead to iron chlorosis.
  • Fertilization: Go light on fertilization. Apply one-fourth cup of 21-0-0 (or equivalent) per established plant, broadcast under the trellis, and water in.
  • Harvest: Flavor is the best indicator for home gardeners to determine harvest time.

Common Grape Pests

Fruit:

  • Birds: Bird netting may be necessary to protect the fruit.
  • Botrytis Bunch Rot: Often a problem with heavy canopies due to inadequate pruning and poor air circulation.
  • Spotted Wing Drosophila Flies: These can affect ripe grapes.

Plants:

  • Powdery Mildew: Refer to CSU Extension Fact Sheet #2.902 for management.
  • Iron Chlorosis: Typically a symptom of over-watering. Refer to CSU Extension CMG GardenNotes #223 for more information.
  • Root Rots: Poor soil drainage can lead to root rot issues.
  • Weeds and Diseases: Grapes do not tolerate competition well, so adequate control is necessary.

By following these guidelines, you can enjoy a bountiful grape harvest in your Colorado garden. Happy gardening!

For more detailed information, call or visit Echter’s Garden Center or contact your local CSU Extension office.

Growing Blueberries: A Comprehensive Guide to Blueberry Care & Culture

Blueberry bushes are an excellent addition to both edible and ornamental landscapes. They not only produce delicious, nutritious fruit but also enhance the garden’s aesthetic with their glossy, deep green leaves in summer and vibrant scarlet foliage in autumn. Here’s how to successfully cultivate blueberries, particularly in regions like the Rocky Mountain West, where soil conditions may pose a challenge.

Essential Growing Conditions

To thrive, blueberries require well-drained, acidic soil (pH 4.5 – 5.5) rich in organic matter. They should be planted in part shade/shade locations and protected from harsh winter winds. Given that naturally acidic soil is rare in the Rocky Mountain region, consider the following methods to create suitable conditions:

  1. Soil Replacement: Remove existing soil from the planting area to a depth of two feet and replace it with a mix of 50% good commercial topsoil and 50% horticultural sphagnum peat moss. Adding extra compost is also beneficial.
  2. Container Planting: Use half a whiskey barrel or a large 20″ plastic pot with additional drainage holes. Fill with the soil mix mentioned above and sink the container into the ground.
  3. Raised Beds: Build a raised bed (3-4 feet wide and 8-12 inches high) using the same specialized soil mix.

Regularly test the soil’s pH using test kits available from Echter’s or other local garden centers.

Plant Care Tips

  • Mulching: Apply a layer of bark chips to conserve moisture, cool the roots, and suppress weeds.
  • Watering: Maintain continuous but moderate moisture throughout the growing season. Avoid over-watering by checking the soil’s top inch for moisture before watering.
  • Fertilization: Annually amend the soil with compost and regularly acidify with products like Ferti-lome Evergreen Food or Miracid. Start fertilizing in May, just before bloom, and continue as directed on the fertilizer label.
  • Pest and Disease Control: Insect problems are rare but can be managed with Malathion if necessary. To prevent fungal issues, water in the early morning and prune correctly.

Bird Control

Birds such as robins, finches, and starlings enjoy blueberries just as much as we do. To protect your crop, cover shrubs with Ross Garden Netting as berries begin to ripen, following the manufacturer’s instructions.

Harvest and Storage

Blueberries are harvested from July through September. Store them in a refrigerator at 32-35°F to keep them fresh for 10-14 days. Fresh blueberries freeze well and maintain their taste, texture, and appearance for up to two years when stored at 0°F. Always freeze blueberries unwashed to preserve their natural protective coating. They can also be canned or processed into syrup.

Winter Protection

For best results, protect blueberry bushes during winter:

  • Apply 4-5 inches of bark mulch around the base in late November after the ground freezes. Remove the mulch in April.
  • Water during extended dry periods or when there’s no snow cover.
  • Stop fertilizing by the end of July to allow plants to harden off before winter.

Pruning Guide

Proper pruning is essential for healthy blueberry plants and optimal fruit production:

  • Establishment Years (First Two Years): Remove winter-killed and diseased wood. Prevent fruit setting to aid establishment by rubbing out flower buds in early spring.
  • First Pruning Year: Prune in early spring after the bush has been planted for two seasons. Remove diseased or dead wood and any crossing canes. Keep two or three healthy canes.
  • Second Through Fifth Years: Continue the same process each year, maintaining a goal of 12 healthy canes of different ages by the fifth year.
  • Maintenance Pruning (After Fifth Year): Maintain the bush at 12-15 canes, pruning out the oldest canes annually and leaving two or three new ones.

Pruning, along with proper soil pH, drip irrigation, and mulching, significantly impacts berry size and quality. Annual pruning ensures consistent, high-quality fruit production.

In summary, with the right care and attention, blueberry bushes can be a fruitful and beautiful part of your garden. By following these guidelines, you can enjoy bountiful harvests of delicious, nutritious blueberries year after year.

For more gardening tips and expert advice, visit our website at Echter’s Garden Center or call us at 303-424-7979.